floor jack safety valve adjustment for sale

An overload valve of a floor jack primarily exists so that the jack does not exceed the weight limit of the hydraulic press, which might cause it to break down. Overload valves stop the press from lifting further up if the weight limit is crossed.

The floor jack overload valve adjustment process is very straightforward and only requires you to follow a set of simple steps. However, if you’re trying to adjust the overload valve, chances are that your floor jack is having some trouble holding pressure. In that case, we have some solutions for that as well.

An overload valve is a safety measure to protect the hydraulic press from unwanted damage due to excessive pressure. It works by loosening the connection between the jack handle and the hydraulic press.

When we’re talking about adjusting the overload valve, we’re mainly changing the max weight capacity of the floor jack. To do that, you just need the right screwdriver. It varies from model to model, some use Philips heads while others use binding heads.

Once you’ve got the right screwdriver, find the location of the safety valve. There will be a shield on top of it that you’ll have to remove with the screwdriver. Spot the screws and turn them counterclockwise to release the shield.

After you’ve done that, the valve should be exposed to you. There are mainly two types of valves used on floor jacks. The handle valve and the screw valve. Handle valves have a handle, while screw valves have a hole for the screw to go through.

For a handle valve, you just have to hold on to the handle and rotate it to adjust the weight overload on the floor jack. Rotate it clockwise to increase the maximum weight capacity and counterclockwise to decrease it.

These valves are typically very sensitive so a small turn could drastically change the output. So, try it in small amounts and figure out the correct amount for you.

For a screw valve, you will need a corresponding screwdriver. Typically it is the same as the shield’s screws, but according to your model, it could be different.

Safety Note: Before attempting to put pressure after adjustments, check the instruction manual of the floor jack for the maximum supported weight capacity. Normally, the valve will be set to 90% of that max capacity. So, you can at best increase it to 100%. Going beyond that will be very risky as it can damage both the floor jack and your vehicle.

This is a very common issue for which people consider adjusting the overload valve. A loose valve can indeed cause your floor jack to suffer such problems. However, that’s not the only cause.

The hydraulic press will fail to operate if the oil levels are above or below the given margins. Also, if the oil is of low quality, it might cause friction which can also prevent it from working properly. To maintain the proper hydraulic level, you should fill your jack with oil correctly and safely.

To know exactly what types of fluid are used in a floor jack, check out this article where we have explained and recommended the hydraulic fluid to use in your jack.

Hydraulics work by using highly pressurized compressed air. After long-term use, some of that air can leak into other parts of the machine causing havoc. The air mostly gets trapped in the oil chamber. To remove air from the floor jack, you just need to bleed it.

The final most obvious consideration would be that the floor jack is damaged. In most cases, it’s the hydraulic press. Repairing a broken floor jack is not worth the effort and the money. You’re better off getting a new floor jack.

Keep in mind that the overload valve is a safety measurement. So, a floor jack overload valve adjustment should only be done under your own circumstances. To be on the safe side, never exceed the given weight limit of your floor jack.

A hydraulic jack serves one fundamental goal: the lifting of heavy loads. Jacks are designed to provide force multiplication to enable a worker to amplify their strength through the jack"s hydraulics or mechanics to accomplish this goal.

There are two main types of jacks commonly in use; one type uses hydraulic pressure for lifting (hydraulic jacks), while the other uses a screw thread to achieve lift (mechanical jacks). Of the two, hydraulic jacks usually provide higher lift capacity and are more reliable.

Hydraulic jacks are available in two varieties: floor jacks and bottle jacks. Floor jacks have a horizontal shaft that pushes on a crank. The crank connects to a lifting pad that rises vertically. These jacks are capable of lifting several tons.

Bottle jacks have been around longer, and their name derives from their resemblance to an old-fashioned milk bottle. Bottle jacks have a vertical shaft that raises a platform called a bearing pad. They can lift up to several hundred tons, depending on the specific capabilities of the model being used. However, these jacks typically cannot lift the load to the same height as with a floor jack.

Both types of jacks operate under the same basic principle: In a closed container, the pressure is the same in all directions. In the case of a hydraulic jack, this container is a cylinder, and it holds incompressible hydraulic fluid. Hydraulic fluid is forced into the cylinder through a check valve that prevents the fluid"s backflow. The check valve keeps the cylinder pressurized so the load does not drop. As pressure builds in the cylinder, the force pushes upward on the plate of the jack and lifts the load resting on it. The weight of the load lowers the plate when the check valve is released, allowing the hydraulic fluid a path to exit.

There are some issues that are common to all types of hydraulic jacks which can impact their operation and safety. At some point, users will likely encounter leaks, rams that won’t lift, safety valves that get tripped, damage to the frames, and jack handles that kick back. While many hydraulic jack repairs are easy to accomplish, others might require the assistance of a professional.

Leaks, in particular, are extremely common, and result from a failed or dislodged seal or O-ring. Repair involves draining the hydraulic fluid, disassembling the jack, and inspecting the seals. Be sure to look carefully for cuts, tears, seals that are out of place, degradation, scratches, and so on. These issues are an indication that the seals or O-rings need to be replaced.

Repairing leaking seals can be a significant undertaking, especially for those not experienced in jack repair. Novices might want to leave this type of issue to a professional with the requisite experience. Also, if the leaked fluid is cloudy or foamy, that indicates the presence of water or air in the hydraulic system and could mean that the hydraulic fluid needs to be replaced and the potential source of the intrusion investigated.

Jacks may also be overloaded, causing the safety valve to trip. The purpose of this safety feature is to prevent the jack from being loaded beyond its rated operating pressure, typically measured in pounds- force per square inch (psi). A jack will not behave the same way after the safety valve has been tripped. The ideal way to address this issue will vary by manufacturer, so always consult the service manual when this occurs. Professional service is recommended in these instances to restore safe operation of the jack.

In other cases, rams may stop lifting, which is usually the result of insufficient hydraulic fluid in the reservoir. Luckily, this is a repair that even beginners can handle. When there isn’t enough hydraulic fluid present, air may become trapped inside of the system. The solution here is to add the appropriate amount of hydraulic fluid, then turn the jack to its release position. Next, pump a few times to purge out the trapped air. Then, refill the reservoir and place the seal cap back on. Be careful to avoid introducing contamination (such as dirt and dust) to the hydraulic system while adding fluid, and never mix two different types of fluid.

Hydraulic jacks are powerful devices for lifting, but like any other mechanical or hydraulic system, they will inevitably require maintenance and occasional repairs. While someone with fundamental mechanical skills may accomplish some repairs, others are best handled by a hydraulic professional. Be sure to consider the options carefully before deciding on a course of action.

This is a 1 1/4 ton hydraulic floor jack my father passed on to me.  He bought it new during the 1970s. It began to leak down a little a few months ago. The lift arm no longer rises when the handle is pumped up and down. (I was able to pull the lift arm up by hand and it settled slowly enough that I could make a photo with the arm partially raised.)

I checked to be sure it was adequately filled with fluid, but that was not the problem.  A few months before this problem, there were bubbles coming up through the vents at the filler plug.  At that time I raised the lift arm with the handle, released the jack"s valve, and let the arm fall slowly several times to purge air from the system.  Finally, one day, the lift arm would not rise at all. If filling with fluid and purging air from the system do not restore function, there is probably internal leakage, even though fluid is not leaking from the jack.  From what I have read, forty years of service is a reasonable time for a hydraulic jack to operate before it needs a rebuild.

A word of caution: Rebuilding this jack presented several challenges that seemed almost insurmountable at the occurrence of each.  Rebuilding this jack was much more difficult than simply replacing a few "O" rings, and it required more than the very few hours some say are required for rebuilding a jack. Further, I had to make several special tools to get the job done. If you want to attempt rebuilding a jack and you are not a member of Instructables, I would encourage you to pick a password and a screenname, and join.  Doing that will allow you to download a PDF of this Instructable for printing, or to view at any time later on your computer, assuming you wish to consult what I have done as a guide.

When putting fluid into a jack never use anything other than hydraulic jack fluid.  Do not use motor oil or brake fluid. Brake fluid makes the seals swell.

At this link you will find one man"s description of how he rejuvenated his twenty-five year old jack by flushing its insides with a solvent, letting it dry completely, and filling it with fresh hydraulic jack fluid. It could be worth a try. I did find one manual for a floor jack that said the fluid should be changed every year. The procedure is to place the jack over a large pan, remove the filler plug, turn the jack on its side and let it drain. Then fill it again.

Several firms sell rebuild kits for hydraulic jacks. I found Blackhawk Parts and ordered parts on-line. My jack came with the Fleet brand name. It was sold through NAPA Auto Parts.  It should have been easy to find my jack among the listings for Fleet jacks on the Blackhawk Parts web page and order the appropriate rebuild kit, but it was not.  So, I sent an e-mail to Blackhawk Parts with the name of the manufacturer and the model number.  It is good that I did.  The kit I need is not the one I would have thought, but is actually for a Lincoln/Walker jack. Although my jack has the Fleet name, it was actually made by someone else.  I paid about $45 for the parts kit, plus $11 shipping. That is a fairly typical price for a rebuild kit.

I decided not to open the parts kit until I was certain the parts it contains match what I see on my jack as I dismantle it.  I will have less difficulty exchanging an unopened parts kit than I would have trying to exchange a kit I had opened, in case the wrong one was shipped to me.  In the photo you can also see the paperwork that came with the parts kit.  It will help, too, if an exchange were necessary.  And, I do not want to risk losing any parts by opening the bag early and having something roll out.

The rebuild kit does not include any instructions.  The Blackhawk Parts web page offers a few cautionary and a few safety notes, but no helps on the rebuild procedure for the Saturday mechanic. e-How does offer a step-by-step procedure for rebuilding a hydraulic jack in text, but it is quite general. There is avery helpful link at the e-How page that takes you to a set of photos and some useful notes on critical stages for doing work on a low price imported hydraulic floor jack. Some of these things would be very helpful for the proper assembly, too. Floor jacks are remarkably similar, despite small differences. See the next step for information on helpful videos on-line.

The graphic for this step is an exploded diagram of a hydraulic jack and a list of parts.  This one is from aHarbor Freight jack. Diagrams like this one are easy to find on the Internet.  Just search for "hydraulic jack manual."  Diagrams like this one help with the names of parts and with a visual understanding of how the parts fit together. You can enlarge images in your browser to see more detail, or save them in PDF and do the same. But, if you are able to watch the videos linked in step 3, you will see how the parts fit together, too. (The day may come when those videos are no longer available on the Internet.)

There are many videos related to hydraulic jacks at YouTube, but most of those are not really very helpful for a rebuild, even though their titles are enticing.  A floor jack is a really a bottle jack laid over onto its side and installed inside a frame equipped with casters, a handle, and a lift arm. This video shows how to remove the bottle jack unit from the frame. The floor jack in the video is my Fleet jack with a different name and paint color on it.  Some jacks are the least bit different.  You may also want to view this video.

If you do not want to rebuild the bottle jack unit yourself, you can use either of these videos to remove the bottle jack unit from the frame of the jack and simply take it to a repair shop near you.  The cost of a rebuild at a shop is said to be around $150 to $200 plus parts. The e-How article linked in step 2 contains a word of caution. If your jack is a cheap import, it may not be worth a rebuild.  The machining is not always as good as on the older models made in the USA. Further, the correct parts kit may be impossible to get. You may find it more economical simply to buy a new jack.  Classic jacks made in the USA are generally considered worth the expense and effort of a rebuild.

First photo--The halves of the jack frame will need to be spread to get the bottle jack unit out for repair. Loosen the nuts on the axle for the lift arm considerably, but do not remove them. There is one on each side of the jack frame. The nuts on my jack are 15/16 inch in size.

Second photo--Two bolts on each side hold the body of the bottle jack unit to the frame.  Remove all four. (One is partially backed out already.) Although the man in the video from step 3 removed the casters, that is not really necessary to access the bolts on this jack. I did fine without removing the casters.

Fourth photo--A universal joint twists to open and close the release valve. The upper end of the universal joint is a piece of hex stock. It fits into a hex socket in the bottom of the handle.

Fifth photo--Lift the jack frame and the bottle jack unit remains on the work surface, even though attached to the lift arm by hinged extensions. Use a pair of pliers to remove the end of the return spring from the pin.

Sixth photo--The rams from the jacks shown in the videos attach to the frame with a cotter pin.  On this jack a pin both holds the end of the spring and secures the block in the photo to the top end of the ram.  Flip the bottle jack unit over and drive the pin most of the way out with a hammer and a punch.

Place the bottle jack unit into a pan and drain the oil as best you can. On the bottle jack unit in one of the videos it was easy to work the plunger in order to extract more of the oil. The spring on the plunger is too strong for that on this jack.  Be aware that additional oil will pour out of the jack in coming steps. Have a pan or newspaper available to catch it and minimize the mess.

The first photo shows the ram and ram nut (or tank nut, also top nut) at the end of the bottle jack.  Most ram nuts are hexagonal.  This one has two slots for a special spanner wrench.  In the video from step 3 showing a man taking the ram nut off of a bottle jack, the ram nut came loose quite easily.  On my jack the nut was stuck on very hard.  I placed the bottle jack unit into my vise and tried to loosen the ram nut with a very large pipe wrench.  I only did a little cosmetic damage to the nut. It would not loosen.  I soon realized that my workbench and vise were not equal to the task, either.

The third photo shows the tool in use.  Check the yellow text boxes.  My vise did not have enough leverage to hold the bottle jack unit, so I bolted it upright into the jack frame and used the jack frame as my own long bar for leverage. In order to make that work, I planted my foot against the end of the frame that is not shown in the photo. I had to strike very hard with a 16 ounce ball peen hammer, but after about five or six strikes, the ram nut began to move. My tool worked and I was able to loosen the ram nut with the ram for removal from the bottle jack unit.

First photo--Unscrew the ram nut until it and the ram can be pulled from the bottle jack unit.  The ram nut simply pulls off of the top end of the ram.

The outer shell of the oil tank appears to be securely fastened to the base of the bottle jack unit, but it is not. Press against its side and it tips off to one side immediately. There will be some oil that runs out onto the work surface. Put down some newspaper or a pan to catch it.

Third photo--Unscrew the universal joint assembly for the release valve. Insert a magnetic tool and pull out the cone-shaped plug.  The hole from which it came is visible behind the magnet tool.

Fourth photo--Place the bottle jack unit in a vise and use a wrench to remove the plunger mechanism. I had to tap on the end of the wrench with a hammer to loosen it. On my jack a 1 inch wrench was required.

Move your cursor over the text boxes in the first photo. for part names, etc. The cylinder would normally be removed for a rebuild. But, this one is stuck very tightly. Remember how much difficulty there was in removing the ram nut in step 6. It screws to the cylinder, so the cylinder should be difficult to remove, too. It is not as easy as the video linked in step 3. I tried, but could not get it to loosen. There actually are no "O" rings or seals below the cylinder on this jack.  Removing it does not give access to any removable parts. I did notice some oil at the bottom of the cylinder appears dirty.

There are two metal plugs in the body of the bottle jack unit. Two large screws are below them.  See the text boxes again.  This site warns NEVER EVER to open these. It also has a diagram of what is inside. (Scroll down to the middle of the web page.) The author"s concern is that the small balls in the valves can be lost, and the jack would become useless. Get a shallow cardboard box with no holes in the bottom or a large pan and work inside of either one. If any balls roll away, they will be contained inside the box or the pan. Also, extra balls are included in my kit. Even if the balls were not included in the kit, precision steel balls can be purchased at a bicycle shop in a series of sizes. Check the link in this paragraph for the sizes normally used. The ball sizes in my jack are: 5/16 inch (7.94mm), 7/32 inch (5.55mm), and 5/32 inch (3.96mm). I measured them with a caliper through the plastic parts bag. I want to do as complete a rebuild as possible. Dirt may have found its way into the passageways where the balls are. The balls could also have rough surfaces through years of use.

If I turn the jack body back and forth I can hear metal balls rolling inside passageways.  I drilled a hole in the center of each of the metal plugs.  Then I inserted a slightly larger sheet metal screw into the hole until the threads bound against the hole I drilled. I placed a pair of pliers under the head of the screw and pounded against the pliers with a hammer to pull the metal plug out of the jack"s body.  I repeated the process with the other plug. New plugs are included in the parts kit.

The second photo shows the bottle jack unit"s body, but inverted so it was easier to hold while operating the camera.  The metal plugs have been removed. Both holes have a large screw inside them.  The one on the right is recessed so far that it is not visible.  It is the safety overload valve.  This valve protects the jack"s seals from failing under a load heavier than the jack"s rating.  When the safe range of the jack is exceeded, the safety overload valve opens like a pressure regulator to allow oil to return to the tank rather than entering the chamber for the ram. This screw has to be set so the safe level of pressure is not exceeded. In order to do that at home, I carefully turned this screw and counted by half-turns until it bottomed out.  My screw was set to 1 3/4 turns above or looser than the bottoming out point. When it is time for reassembly, I will turn the screw gently until it bottoms out, then I will back it off 1 3/4 turns. The safety overload valve should then be set very close to the original factory calibration.  One author noted that some jacks fail because the safety overload screw unscrews itself, which sets the jack"s lifting ability to a much lower threshold, and the arm may not lift what you want to jack. I found this screw turned with enough resistance that it is not likely to shift its position by itself. That same author also said most safety overload screws are about two turns looser than the bottoming out point.

The fourth photoshows another special tool I made.  The screw for the check valves is quite tight.  I tried the largest screwdriver I had (3/8 inch wide blade) with a wrench on its square shank.  The blade on the screwdriver broke! The screw slot is 1/2 inch across the diameter of the screw and almost 1/8 inch wide. I bought a short bolt 5/8 inch in diameter.  It is #8 on the hardness scale. Near the end I ground the diameter down until it fit nicely inside the recess for the screw.  I kept a cup of cold water near my grinding wheel to avoid softening the bolt with heat. I ground a rough profile by sight. I moved the bolt to a vise and finished cutting the profile of the screw slot by means of a hand file. I checked the dimensions with a digital caliper.  When my improvised screwdriver fit the screw and its slot, I tapped on the bolt"s head to be certain it had fully seated in the slot.  I used a wrench on the bolt head and the screw came out with no difficulty, at all.  I had tried to buy a large screwdriver, but could find none this large.  This improvised solution cost me $1.65 for the bolt and a few minutes of time.

The first photo shows a paper towel I pressed into the cylinder and rotated with a screwdriver without letting the screwdriver touch the sides of the cylinder. (Be careful not to scratch the inside of the cylinder.  A 1/2 inch dowel pin would have been a safer tool to use.)  Jack fluid is clear.  The towel shows how much dirt was in my jack"s oil.  In addition to sopping up some dirty oil still in the cylinder, I poured a little clean jack oil into the openings and passageways.  Most of it collected in the opening for the plunger.  At first this oil was cloudy. After a few tries, it was clear. I think this should adequately clean the jack so that it can be reassembled.

Inspect the seats in the bottle jack unit"s body for signs of rust and pitting.  The seats need to be clean and smooth.  When I let sunlight shine into the recesses where there are seats, I saw more dirt.  I used a wooden dowel rod to scrape and break loose any dirt I could find.  I poured some jack oil into the holes to flush the dirt away.

Second photo--Clean the groove that receives the tank"s outer shell. It has some brown dried oil residue. Something brass would be ideal.  It would be tough enough to remove the residue, but would not scratch the machined surface. Someone said jack oil is a vegetable oil. The oil residue is certainly like what I have seen in the kitchen from vegetable oils.

I kept the bag of parts inside the same shallow pan in which I assembled the bottle jack unit.  This is so I am less likely to lose parts, especially the steel balls.

First photo--This shows the plunger body and the plunger parts.  At the left three leather seals are shown.  My jack does not use these. Several different parts came in more than one version. I think the same parts kit is sold for several similar, but different jacks. I have some parts I will not use on my jack.  In the center area of the parts are the steel washer and the locking nut. The other two parts at the right are the old seal I removed.  It has an oily sheen. Just below it is the replacement part my jack requires.

Second photo--Coat the new neoprene seal with fresh jack oil. During the installation of all parts, double check for any grit or dirt sticking to the oily parts and remove it before the installation of that part. Install the new neoprene seal, rounded end first.  Install the steel washer and the locking nut.  I will discuss how tight to tighten the locking nut after treating how to install the spring assembly onto the plunger body. I made a special tool for putting the plunger assembly back together. It is made from steel wire about 1/8 inch in diameter. The wire came from stubs of concrete reinforcement wire broken off from a friend"s foundation for his new garage.

The third photo shows how this special tool is used. I chucked this tool in my small drill press. The circle of wire at the end of the tool fits over the top of the cap for the plunger assembly. The two straight pieces welded crosswise allow the quill of the drill press to exert pressure downward and to collapse the spring so the "C" ring can be attached.  Notice that the bottom end of the plunger body presses against wood so the smooth machined surface is not scratched.  I used an adjustable pliers to close the "C" ring. My drill press has limited adjustment. I used a couple of pieces of wood on the drill"s base in order to achieve the desired distance between the chuck and the surface supporting the smooth end of the plunger.

Check the plunger for dust and particles of wood. Thread the plunger into the base of the bottle jack unit. Tighten with a wrench and hit the wrench several times with a hammer to make a good seal, since there is no "O" ring or copper washer to make the seal.

First photo--I have a dental pick I can use to remove old seals. This "O" ring shows cracks from age when stretched a little.  Match the new "O" ring from the parts kit to the old "O" ring.  Coat it with jack oil.  Install the new "O" ring.

Second photo--Install the conical metal seal in the hole for the release valve.  The pointed end goes in first.  Tamp on it with a small screwdriver to make sure it seats at the bottom of the hole.  Thread the release valve into the hole.

First photo--The hole for the check valves has a copper sealing washer inside it.  The old washer is barely visible in the hole.  Note its color.  A new copper washer is supplied in the parts kit.  The old washer has compressed to fit very tightly.  There is no good way to remove it.  I did not want to fill the passageways in my jack with copper shavings from digging it out in pieces.  I decided simply to place the new washer on top of what is left of the old washer.  (This photo was made before the plunger and the release valve were installed.)

Second photo--Install the parts in the order shown in this photo from step 8. (The release valve and the plunger are not shown in this photo.) Use the new balls from the parts kit. Do all of this inside a pan or shallow cardboard box so none of the balls are lost if one gets away from you. Tamp the parts down with a small screwdriver so they settle down as far as possible in their hole. Carefully start the screw plug with a screwdriver. It is easy to crossthread. Use the special screwdriver made from a hardened bolt to tighten the screw plug with a wrench.

Third photo--Install the parts shown in this photo from step 8. Drop the new ball into the hole. Insert the spring into the open end of the cap and drop both into the hole.  Insert the screw plug. Carefully turn the screw plug until the valve assembly bottoms out.  Back it off 1 3/4 turns.

I chose not to install the metal plugs that close the valve holes yet in case I would need to open one of the valves during testing of the jack to correct a problem.

Coat the inside of the cylinder with jack oil before inserting the ram. You should be able to pull the ram up and push it down with your hand. A seal too large in size makes the ram very difficult to install and to move.

Second photo--Clean the tank shell, both on the edges that mate to make a seal and inside. I found quite a bit of dirt inside mine. The dirt had not entered the jack from the outside, but appeared to be residue that had formed from changes in the oil.  I applied some jack oil to the inside of the tank and wiped it with a clean paper towel. I did this several times until I could no longer feel anything gritty with my fingertips.

Retrace what you did in step 4, but in reverse, to bolt the bottle jack unit back into the jack"s frame.  (The photo is from that step.) While the bolts are still loose, put the handle"s yoke in place.

I used about 20 ounces of jack fluid. Around 12 ounces was used to fill the jack. The rest was used for cleaning and flushing the bottle jack unit. The fill hole is 1/4 inch in diameter.  Even though the bottles for the jack oil have a pointed end, some spurts out while trying to get the bottle end to the hole, and it makes a mess. Get a funnel with a very narrow end.  This is one I made specifically for this job from some sheet metal.

I filled the reservoir in small steps. The jack"s release valve was open. Occasionally I pumped the yoke for the handle.  When oil was at the level below the plug hole, I pulled the lift arm up and let it fall two or three times. This is to draw oil through the jack. I pumped the yoke between five and ten times to remove any air lock in the check valves.  I checked the oil level again a couple of times. Then I returned the reservoir cap.  The reservoir cap appears to be open, but actually has a small felt filter inside it.

Update: After using my jack a few times, it tends to throw off extra oil through the felt filter in the reservoir cap. I do not have the original instructions for this jack, so I do not know exactly what the recommended fill level is for it. From what I have read, some jacks are to be filled to the bottom of the hole while the floor jack is level on a floor. Others vary between just covering the cylinder with oil to slightly below the fill hole. At first I thought I might have a leak, but it was just the jack throwing off extra oil. This extra oil may also be due to the jack evacuating air trapped inside the jack. There are bubbles in the oil vented. One source suggested raising the jack fully and lowering it slowly twenty or so times to remove all air that might be trapped inside the jack"s passageways. Check the oil level to keep it at the desired level.

My jack worked as it should immediately. The real test is to lift something heavy with the jack. I left the jack in this position for a few minutes. It did not leak down that I could see. Now I can use a hammer to tap the metal caps into the holes for the safety overload valve and for the check valves. I will check the fluid level again after I have used the jack several times. I will also watch for signs of leakage. It is also a good idea to oil or grease all moving parts on the jack now and regularly in the future.

Troubleshooting--What do you do if you have rebuilt your jack, but it still does not work under load? Be certain the oil level is correct. Here are instructionson properly filling a floor jack. The jack could be air locked. This site says to open the release valve and pump the handle rapidly 10 to 15 times in that case. Here is a link to a document on troubleshooting hydraulic systems, like a jack. If necessary, check to be certain all check valve balls were installed properly. Check for leaks.

Conclusions--I did not find any clearly damaged seals in my jack, other than cracks in an "O" ring on part of the release valve, but it was a non-critical part. I did find dirt in the oil. I expect the seals were just old and less efficient. It feels good to have my jack working again, especially since it once belonged to my father. Rebuilding a hydraulic floor jack was much more difficult and a lot more work than I expected from information I had gathered before I began. I found some parts were not as easy to remove as I expected from videos and other helps that I linked earlier in this Instructable, and I had to make several special tools. I first had to develop those in my mind. Then I had to design them and build them with materials I already had. Fortunately, I have a welder and was able to do that without too much difficulty.

I can easily understand why many suggest a person ought simply buy a cheap jack and replace it with another when it fails. I have a hard time doing that, no matter how much financial sense it might make, That seems like the waste of a good tool containing numerous carefully machined parts. An imported floor jack comparable in capacity to mine lists for around twice the cost of the parts kit I bought, sometimes even less than twice the cost of the parts kit. I do not know if my Fleet jack will last longer than an import jack.

Knowing all I know now, I might suggest flushing out old jack oil every decade and replacing it with fresh, clean fluid. Even then, I am not sure draining the old fluid and refilling the jack with new fluid would have removed all of the dirt I found. Some of it was in places that seemed to hold the dirty oil in that particular place. The oil in the reservoir had always appeared clear and clean. Still, neoprene seals used in hydraulic jacks do harden or crack and will fail to seal properly in time.

Owning and using a hydraulic jack is often a necessity. But, it has costs over time. Those costs mean the eventual repair or replacement of a jack.  If you choose to repair your jack, you have the option of doing it yourself or of taking it to a shop.  If you choose to do it yourself, you will learn a lot, but it may require more of your time and be more difficult than you expected. If you take it to a shop, there will be a cash outlay that will likely be a fair amount greater than the cost of a new imported jack.

Several times I feared I had ruined a vital part on my jack, or was about to do so, simply because I was without knowledge and experience related to rebuilding a floor jack. It is my hope that this Instructable will enable others who wish to do so to rebuild a hydraulic jack with confidence and without some of the near mishaps I experienced. I wish someone had published this before I began to rebuild my jack. It would have saved me time and trouble.

Thank you. That is what I expected you have. I suppose you could also try to collect names of jacks using those gesrs and inquire of them to see if the gears are available as replacement parts.0

My CRAFTSMAN floor jack has 3 ports (valves)..... could you tell me what each one is and how to set them ? It was made around 2005...... (MADE IN CHINA) model #214.50145

I rebuilt this with new parts no problem...... I just did NOT check the turns for the check valve and safety overload valve and a 3rd one ??? ( factory settings) Any help would be greatly appreciated !

Thank you for your gracious comment. I hoped someone like you might see this and comment, especially in case I might have given totally false information, and you would correct me. This is my first intrusion into hydraulics, other than replacing a couple of brake lines on a previous family automobile and bleeding air from the system afterward. As I mentioned in the Instructable and in response to a previous comment, I needed to rebuild my jack; but, could not find all of the information I felt I needed. I wanted to document what I did, should I ever need it again, and also make it available to anyone else in the situation in which I found myself.

What would be your recommendation on the type of solvent to use and how long would let it soak inside the jack prior to rebuilding the 45+ year old hydraulic floor jack:

Ajack does not get hot and accumulate burned residue. Most parts will wipe clean with a rag. Sometimes there was residue where oil dried out. A wooden popsicle stick cut off square makes a good tool for removing oil residue without scratching the steel.0

There is one thing I learned that is worth knowing. Rebuild kits for hydraulic devices, even pneumatic devices, sometimes include two nearly identical O-rings, but one is slightly larger. One works, but the other does not. If an O-ring does not seem to fit, or the device does not seem to work, check for a nearly identical O-ring. A couple of years ago, my son-in-law rebuilt a nail gun. It did not work after rebuilding. He asked me to look at it. I replaced an O-ring with a nearly identical O-ring that was just a little different, and suddenly the nail gun worked just fine. I ran into something similar on rebuilding my jack.0

Very very good posting on rebuild of floor jack.Will be helpful with much detail for anyone wanting to complete a jack rebuild Thanks for all your suggestions, KneeWalker0

I understand. My life situation has changed. I am retired with a car that gets about all of its service at the dealership. We moved across the country and I left my floor jack with a brother-in-law. Here there is a son-in-law who will lend me a floor jack when I need one, but that has not happened. But, it is something you can check on your bucket list.More CommentsPost Comment

Hydraulic Jacks need to be bled on occasion, This can be account of a Low Oil situation allowing Air to be ingested, Heavy Movement which can allow the oil to slosh around in the Reservoir or a Weak or Poor Pump seal that will extrude Oil/Air into the system. A General rule of thumb is 1st make sure there is sufficient oil in the Reservoir, then simply put the jack in the Release position and Pump the Handle 6-8 times. What this will do is make the circuit between the Reservoir, Through the Valve system, Through the Release vein and back into the Reservoir all the time purging the lines from any Air.

A general Rule of Thumb is on Floor jacks, The oil should rest aprox 5/16" below the fill hole or rest just above the inner cylinder, when peering thru the hole. On bottle jacks the Fill hole is generally on the Reservoir aprox 3/4 of the way up, It should be filled till oil starts to trickle out of the hole when the jack is in the Upright position. Always Check oil levels with the Jack arm lowered or Bottle jack Ram retracted.

2. Unfortunately the Next step requires you to tear into your jack and Inspect the Individual Seals. There are some Tutorials Available to cover some of the Most Popular Models.

1. Now i cant get the Tank Nut off... Grr... Ok first and Foremost, Make sure it is a Threaded Nut, Some Jacks use a Internal C-clip to get to the Ram. If its Threaded The Thread is always been Standard (Lefty Loosey/Righty Tighty). These Tank nuts are Extremely tight, because alot of them (not All) need this torque to seal the Reservoir at both ends (Metal to Metal). First and Foremost, a Proper sized Tool will play dividends, If you dont have the proper sized socket/Wrench you can use a Pipe Wrench on the "Hex" style nuts. It will leave teeth marks, If this bothers you... Go buy the Correct Socket.

2. Next you will need a Vise or Press capable of Holding the Unit while you attempt to unscrew the Nut, Dont be afraid to add Leverage, I keep a 6ft piece of Square tubing that slips over a Breaker bar. I also manufactured a piece that mounts between the floor and the nose of the Unit to keep things on the level while i levy on that cheater bar.

When you adjust the Plug down it compresses the Spring which in turn adjusts the Seating pressure of the Ball/Cone. All of your seals have a Maximum Operating PSI, When the Overload is properly adjusted it is set to OPEN up when the Cylinder PSI exceeds the Working pressure of the Seal. This Setting will Vary from Jack to Jack, Based off of the Cylinder Bore/Spring Tension etc.. Ive found that over the Years these Heavy springs which are compressed for there entire life lose there tension or Backoff and thus lift prematurely. It takes a specialty Press with a gauge and some minor calculations to properly adjust these.. This is why you shouldnt start blindly turning things. IF you feel the need to get into the Overload during a rebuild, I recommend that you first find out the Current setting by adjusting the Nut completely closed, Taking consideration to count the Revolutions. This way when you go back together you can simply tighten it down and back it off apropriately. LET ME BE CRYSTAL CLEAR... A Hydraulic Jack is Only for Lifting the Load, Once its UP, Make sure you use Jack Stands. NEVER.. NEVER trust your life to a Hydraulic Jack, I dont care what the Brand is, What the Tonnage is etc... JACKSTANDS SAVE LIVES.

Generally when you see any Leakage around the Tank nut, This is a good sign that either the Seal has failed or is compromised, Hydraulic Jacks utilize a Seal in the Top end that is supposed to handle any light leakage (Start up leakage). Its not designed to handle High Pressure blow-bye, You also find instances where the Load will Drop over time, Obviously the more severe the seal problem the more Noticable the decent will be.

2. Type of Seal/Material Used, Alot of you Older jacks used HUGE Ucups versus alot of the Smaller ones used today, It seems when combined with Heavy usage those things lasted along time. The Same can be said for Leather Piston Cups.. Ive seen jacks with 40-50 years of service.

If you want to work under a garden tractor or any other automobile, you need to raise it. This applies if you want to change the tires as well. For this, you can use a hydraulic floor jack. Many people seem to dread this floor jack because they do not know how to use it properly or to adjust it to the desired height. This floor jack operates through a simple mechanism. The jack has a cylinder into which fluids are pumped in small additions. This has the resultant effect of raising the actuator arm. The cylinder then continues to provide the lifting effort because it is hard to compress fluids. This lifting is sustained as long as the fluid keeps being pumped or until the arm extends completely. However, you can still lift beyond the extent of the actuator arm if you adjust a threaded saddle.

On the side opposite the wheels you are raising, place the wheel chocks on either side. Ensure that the vehicle is in first gear if it has a standard transmission or in “Park” if it has automatic transmission. Do not forget to set the emergency hand brake and to remove the key from the ignition. Now, put the floor jack under the vehicle you are planning to lift. The saddle should be aligned with this firm part of the car. Ensure that you pick the most stable part of the car’s body. Before you start operating the floor jack, you should ensure that the fluid bleed screw is closed. This screw is found at the base of the hydraulic jack cylinder. After this, turn the saddle in an anticlockwise manner until you get the height that you are looking for. Different jack manufacturers have different height limits for their saddles. After this is done, pump the handle up and down to raise the floor jack and the saddle, by extension.

Now, to adjust the extension of the hydraulic floor jack, you need to pump fluid into the cylinder so that you can raise the car up to the height that you are looking for. Now, tighten the bleed screw further if you plan on raising your vehicle or garden tractor. The bled screw usually has a horizontal pin. This pin fits perfectly into the base of the pump. To lower the load, you need to turn the bleed screw anticlockwise.

To lower the jack, you will need to turn the floor jack handle anticlockwise at a half turn. You will then notice that the jack collapses a little. This should be enough to allow you to remove the jack from under the vehicle. You then have to step on the floor jack to lower it further and all the way back to its original positions.

In those simple steps, you have now learnt how to adjust a floor jack. This is one of the simplest devices to use and people need to stop thinking that it is a difficult process. You can then teach others how to use the floor jack and become a local hero. There are more info about the best floor jacks.

ARI-HETRA’s Model WS-1945 hydraulic jack is designed to engage the shackle mounts of your heavy-duty military and construction vehicles, allowing you to raise the front and/or rear of your equipment weighing up to 45,000 lbs. Now available on our GSA Schedule (GS-07F-291AA)!

Whether you need a tool for roadside tire changes or you plan to work on your car’s undercarriage, investing in one of the best car jacks is a good idea. The standard scissor jack or lift jack included in most tire replacement kits can get the job done, but they’re difficult to use and often less safe than alternatives.

If you perform any kind of at-home car repairs or tune-ups, you’ll want to invest in a quality floor jack. These recommendations are a good place to start your search. We’ve made an effort to suggest car jacks with various clearances, ton capacity, and price points.

The Torin Blackjack is a low-profile floor jack that is made with heavy-duty steel. A built-in safety overload system prevents lifting beyond load capacity. We like this floor jack because it is very easy to use, rolls nicely on its casters, and is simple to assemble.

While the instructions included with the Blackjack are practically useless, it isn’t too difficult to figure out how to assemble and operate this floor jack. The handle has a comfortable grip, and the low-profile jack easily slid under our test vehicle.

The release valve is integrated into the handle, which you twist when it’s time to lower the pump’s hydraulics. Among the car jacks that we tested, the Blackjack stood out as the strongest, lifting our vehicle with the least effort on our part.

Those who like the Blackjack appreciate its heavy-duty construction and low-profile design. Many are impressed with the value given the relatively low cost of this car jack. It is easy to maneuver with a long handle.

Some people received the Blackjack with parts missing or with broken swivel casters. While this isn’t common, there are multiple complaints on Amazon about this specific issue. There are also reports that customer service is slow and difficult to contact.

This low-cost, low-profile floor jack has a lifting range up to 14.0 inches. It has a 3.5-inch clearance, making it suitable for low-riding vehicles. A built-in safety valve prevents over-pumping and overloading this car jack. We like it for the price and ease of operation.

The F-767 is not as ruggedly built as the Torin Blackjack. However, it is made from alloy steel construction and is generally easy to use. The lever design offers an easy way to raise your vehicle, and this device is ultra low profile (just under 4.0 inches).

Users with low-riding cars especially seem to appreciate this car jack, which is able to neatly slide under such vehicles. The majority of reviews are comments from those who were happy to report that the jack works as advertised with no issues.

There are reviewers who say that they were shipped jacks with missing parts. This appears to be rare, but it can be very annoying if it happens to you. Some also say that it is a little short, and would prefer a jack able to raise their car higher.

The Blackhawk B6350 is a beefy car jack with a weight limit of 3.5 tons for larger vehicles. This steel floor jack has a lifting range of 5.5 to 22.0 inches and built-in safety valves for overload protection. It features an extra-long handle for greater leverage and is the most powerful car jack that we tested.

Operating this hydraulic jack is similar to the other floor jacks that we tested – insert the handle, tighten the release valve, and pump. The included instructions are easy to follow. Generally, we were impressed with the construction and material quality of this car jack. The handle is very long which makes operation easier, and it is covered in a comfortable foam. It has a fast lift speed and is made of high-quality materials.

Though quite heavy, this jack isn’t difficult to maneuver on its wheels. It does take two people to lift, however. This is the least portable jack we tested.

Most are impressed with the high load weight offered by this relatively inexpensive car jack. According to customer reviews, this is a long-lasting jack.

Some have reported poor welds on the handle, which broke for a handful of customers. Aside from that item, the jack is well-constructed. It may ship low on hydraulic fluid (and need to be topped off), but most are satisfied with a jack that can lift 3.5-ton vehicles at this price. The Blackhawk seems to be an especially popular jack for DIY mechanics.

This tiny bottle jack has a 10.0-ton lift capacity (6.0-, 8.0-, 12.0-, 30.0-, and 50.0-ton versions are also available). It can lift vehicles up to 18.13 inches and comes with a one-year warranty. This bottle jack’s small size makes it highly portable, but the design means that it won’t fit under vehicles with low clearance. It did not fit under our first test vehicle (a sedan), so we tested it on an SUV with a higher chassis.

The Big Red hydraulic bottle jack is easy to carry and position, weighing only around 10.7 pounds in total. When first using this jack you must follow the instructions to remove excess air and possibly top up the hydraulic fluid.

The lever is shorter than with floor jacks and doesn’t include a comfortable handle. It also fits together awkwardly – one part slides into the pinched end of the other, and rests that way, somewhat wobbly.

Besides positioning, this jack is harder to use than the standard floor jack, but still not difficult. It has a very high load capacity (10.0 tons) and easily raised the test vehicle.

Many write that this is an excellent option for high-clearance, heavy vehicles. It has a high weight capacity and its portability makes it a popular choice for changing spares. Be sure that it is stored upright, however, as bottle jacks can leak fluid otherwise.

Some have complained about receiving jacks that leak fluid. In the worst case, a few people got packages wet with hydraulic fluid. It’s annoying to need to clean and maintain your new product, but given the shipping distances, this isn’t entirely unreasonable.

The Big Red floor jack is a good low-cost option for a strong car jack. This jack has a maximum lift height of 20.88 inches. It uses a single-piston quick lift pump and is designed with a safety bypass system to prevent overloading.

This car jack comes with an extra-long saddle neck which can save you some pumping when lifting raised vehicles. The neck extension can be removed for lower-clearance vehicles. We found this car jack easy to use if not quite as well-constructed as our other top picks.

What most distinguishes the Big Red floor jack from the other jacks in this review is the neck extension. This positions the jack saddle higher to begin with, meaning less pumping to lift a car. This is helpful if you have a raised car, though is not necessary for low-profile vehicles like our test car.

This car jack is as easy to operate as any well-designed floor jack. However, the handle design doesn’t seem as sturdy or as comfortable as the Blackjack or F-767. Still, we were able to raise and lower our test vehicle with ease using this floor jack.

Happy reviewers like how this jack works, and many mention the extended saddle neck as an appreciated convenience. Several report years of reliable use from this car jack, which is easy to maneuver and pump.

There are some comments about faulty welding on the wheels. Though uncommon, more than one reviewer posted complaints about the wheels failing. Another typical criticism is that the jack lowers too quickly. Some write that when the pressure valve is released the jack falls down very quickly. We did not experience this when we tested the Big Red floor jack, but this issue may be more common with heavier vehicles.

Scissor jacks are accordion-looking contraptions found with many spare tire kits. These jacks use a screw mechanism to raise your vehicle. They are slow and can be difficult to use.

Floor jacks are large and heavy, but stable and easy to use (if more difficult to maneuver). These are the most common type of jack for a garage or workshop.

Bottle jacks are small and bottle-shaped. These often operate with a lever and are easy to use, but can’t lift as high as a floor jack. A bottle jack is a good option for a portable jack but a poor choice for a car with low clearance.

When selecting a jack, you need to pick something that will fit underneath your vehicle before you begin to lift it. Some sports cars and luxury vehicles have especially low clearances, so require a low-profile jack to elevate. When purchasing a jack, consider your vehicle’s clearance compared to the jack’s.

Also, consider a car jack’s maximum lift height. If you have an especially high vehicle like an SUV, smaller jacks may not raise high enough to hoist your car off the ground.

Any car jack is rated to lift a certain tonnage. If you’re buying a car jack to lift your vehicle for repairs, pick something with a weight rating to match the vehicle you’re trying to lift. Keep in mind that to change a tire, you’ll only need to lift half the weight of the vehicle. You should be able to find your vehicle’s weight on the door panel or owner’s manual. The typical sedan weighs around 3,000.0 pounds, while trucks can weigh around 8,000.0 pounds.

How you plan to use your car jack should determine which type of jack you get. If you want to raise your car so you can get under the body to tinker around, you’ll most likely want a floor jack. These are the most stable and provide the best lifting power.

Floor jacks can be large and heavy, so they aren’t reasonable to carry in your trunk at all times, should you get a flat. If you need a car jack for spare tires, a scissor jack or bottle jack will serve you better (keep in mind vehicle clearance if you get a bottle jack, which may not fit under your car unless you have a truck or SUV).

If you need to jack up your vehicle, a floor jack is typically the universal choice for its ability to lift vehicles higher than a bottle jack. Most vehicles also come with a scissor jack that can support the weight of your vehicle but may not be compatible with other car models.

You don’t need to be a professional mechanic to use a car jack, and many jacks are simple to operate. However, there are some steps you’ll want to consider to keep yourself and your car safe. Additionally, drivingtests.org has a detailed guide should our instructions here not suffice.

Before raising your car, you should also have jack stands and wheel chocks. Jack stands support and stabilize your car after it’s been lifted. They are a crucial safety component if you plan to work under your car while it is elevated. Any jack, especially a hydraulic jack, can fail and if that happens jack stands will prevent you from being crushed. Wheel chocks stop your car from rolling while it is elevated.

Before lifting your car from the ground with a car jack, make sure that it is on a level surface, in park, with the engine off, and the emergency brake engaged. If you have wheel chocks, place those behind your wheels.

You don’t want to place the jack just anywhere before lifting your car. If you put it in the wrong spot it can damage your trim or undercarriage. Consult your owner’s manual to find the jack points – typically a reinforced metal plate just behind each front wheel and just in front of each back wheel.

Slide the car jack under your vehicle and start lifting. If you’re using jack stands, set those up once your car has been raised and before you get to work.

Hydraulic floor jacks often need maintenance, sometimes even when new. Before using your jack, be sure to inspect the welds and bolts. Make sure there are no cracks and that every screw is fully tightened. If your car jack isn’t lifting properly it may need bleeding, a fluid top-off, or both.

New car jacks typically don’t need oil replacement for at least a year. However, if the screw or cap covering the oil chamber is loosened or damaged during shipping, your car jack could arrive low on hydraulic fluid.

To determine if your jack is low on fluid, open the oil chamber and inspect the fluid levels. Hydraulic fluid should come up to 1/8 of an inch from the top of the chamber. If you can’t see any oil, you’ll need to add more.

A floor jack like the Torin Blackjack will offer the fastest lifting speed and most stability. However, these jacks are heavy and not something you can store in your trunk for emergencies. For changing a tire, you’ll need a bottle jack like the Big Red Bottle Jack or a scissor jack.

Regardless of which car jack you have, be sure to also use safety equipment like wheel chocks and jack stands. You may not need jack stands just to change a tire, but you should certainly use them if you plan on sliding underneath a raised vehicle.

The automotive jacks in this article went through two rounds of reviews. We started by searching Amazon for top products, looking at customer ratings, Amazon superlatives, and prices. We combed through customer reviews to find a variety of jacks that are consistently rated for quality, durability, and value.

The car jacks that best met these standards were ordered by our team for testing. A team member assembled and tested each jack on a car, lifting it several inches off the ground. Each car jack was given a rating out of 5 stars based on ease of use, durability, and value.

To test each car jack, we unboxed and assembled the jacks according to the instructions (if any were included). We placed each jack under the test vehicle and lifted it several inches off the ground. Our tester was able to note the quality of materials, ease of use, and overall performance.

Based on our testing, we think that Torin, Pro-Lift, Blackhawk, and Big Red are all excellent brands for car jacks. Many car jacks are sold by different companies but manufactured by the same factory, so in some cases, it may be worth buying whichever is cheapest.

Never get under a car that is supported exclusively by a car jack. Even the safest car jack isn’t safe enough to hold a car on its own. While all of the car jacks we recommend (Torin Blackjack, Pro-Lift F-767 Blackhawk B6350, Big Red floor jack, and Big Red bottle jack) are excellent car jacks, you should always place your car on jack stands when working underneath.

Car jacks are reliable for lifting your vehicle, changing tires, or doing work under the chassis. However, no car jack is reliable enough that you should trust it with your life. Whenever working underneath a car be sure to support the vehicle with jack stands and not your jack’s lift arm alone.

A 3.0-ton jack can safely lift up to around 3,500.0 pounds. If the thing you’re lifting is significantly lighter than that, you may not need a 3.0-ton jack. If the thing you’re lifting weighs more than 3,500.0 pounds, you’ll need a stronger jack.

If you’re lifting a car, keep in mind you may only need to lift one side of the vehicle, so if your car weighs 7,000.0 pounds, a 3.0-ton floor jack can raise it enough to change a flat tire or perform oil changes.

A 2.0-ton floor jack can lift vehicles up to around 2,400.0 pounds. This will lift some SUVs, but the typical mid-size SUV can weigh up to 5,000.0 pounds. However, when using a jack, you’re likely only lifting one side of the vehicle, and not the entire car’s weight.

Professional mechanics generally use hydraulic jacks since they can bear the entire weight of a vehicle and allow greater access to work on a variety of issues.

The best car jack stands are best suited for specific maintenance tasks like replacing tires, changing brakes, or working on the underbelly of the vehicle. In other cases, ramps are cheaper and typically safer.