yanmar ym2000 hydraulic pump free sample

Compatible with Yanmar Tractor(s) YM180, YM186, YM187, YM1802, YM1810, YM1820, YM2000 (green chassis), YM2001, YM2002, YM2010, YM2200, YM2301, YM2310, YM2700

New YM2000 owner here. Loader and 3Point worked when cold. After mowing for 10 minutes, lost power to both and in the UP position. Screen filter has been cleaned and new tran/hyd oil JD303.

I had the same problem last year with my YM1500. I opened the connection where the hydraulic line feeds into the valve and it started working again. Evidently some trash was blocking one of the ports. Do this with the tractor at idle--about 800 rpm. A rag over the fittting will prevent the fluid spurting all over everything. If this doesn"t work, the next thing would be to go into the valve, clean it good, and probably replace the o-rings. Hope this helps.

Yanmar is a registered trademark of YANMAR Co. Ltd. Any appearance of the Yanmar name, Yanmar logo, or Yanmar part numbers are for reference purposes only and does not imply that the part is a genuine Yanmar part.

Fig. 2 shows the components of an HST. These are: [1] An input shaft that transmits power from the engine, [2] An output shaft that transmits power from the HST to the vehicle, [3] A control lever that controls vehicle speed and traveling direction (forward/reverse), [4] A center case that transmits hydraulic power, [5] An axial piston pump, [6] An axial piston motor, [7] A variable swash plate that changes pump discharge quantity, [8] A fixed swash plate in the motor assembly, [9] A charge relief valve that determines the pressure of the hydraulic fluid supplied to the HST main circuit, [10] A check valve for closing the main circuit, [11] A relief valve that limits pressure increases in the main circuit, [12] A charge pump that makes up for leaks in the pump and motor, and [13] A housing that holds these components and keeps them immersed in lubricant. Fig. 3 shows an example of an HST hydraulic circuit.

[1] The HST input shaft rotates by the engine power and the HST pump that is connected with input shaft converts the rotational energy into hydraulic energy (flow rate and pressure). [2] When the angle of the variable swash plate is changed, the hydraulic energy is transmitted to the HST motor. [3] The HST motor converts the hydraulic energy back to rotational energy that is in turn transmitted via the output shaft to a sub-shift or other gear transmission. [4] The angle of the variable swash plate can be changed arbitrarily to provide continuously variable gearing in either forward or reverse traveling (see Fig. 4).

In the past we have had several cases with a rear linkage that does not work or moves slowly. Unfortunately, we have not filmed or photographed all of these situations, but we can do our best to tell you about them using facts and examples. Let it be clear that this blog is about hydraulic pumps and any other related problems.

At the start, you listen to the customer and come up with a scenario. In this case, it was clear to us that the hydraulic filter was new and that this could not be the problem. These sometimes get clogged up, but that was obviously not the case in this instance. Then we inspected some other things. Plungers that are known to malfunction or refuse to operate because of dirt (we will come back to this later) could not be the problem. Then one problem remained;

With full courage and tools, we went to the customer and changed the hydraulic pump (very simple). This can be partly seen in the video that will be added to this blog. After the pump was disassembled and exchanged for the new one, we started the tractor and soon found out that it had done nothing. In consultation with the customer, we left the new hydraulic pump in place, as the old one had been running on air for some time and was making unpleasant noises.

Thehydraulic pump has a suction side (in) and a pressure side (out). Logically, there can be no problem on the ‘out’ side, as it would then leak hydraulic oil.

So we continue on the ‘in’ side. We suspected this because there was foam in the oil, pointing to air in the suction side. After inspecting the suction pipe and seeing nothing strange, there was another cause that seemed logical. The hydraulic filter, which the best man had ordered from a colleague who sells filters. Because they often know about general machinery, we will go into more detail about mini tractors.

Anyway, we had taken a hydraulic filter from our warehouse and exchanged it with the current one. Our filter immediately fitted better, although the previous one looked similar to our own.

We start the tractor after mounting and degreasing the hydraulic oil and yes, the noise is gone. Now the big question; does the front loader and the rear linkage work again?

Customer calls us with the problem that the rear linkage of the Iseki TL1900 does not work at all anymore. Also, there is no pressure from the hydraulics anymore. We have made a video of this, however due to lack of time we have not yet placed it online.

The hydraulic pump is the first thing we start with. An important fact is that the Iseki TL series can have 3 different pumps. Therefore, always pay attention to the gearing of the pump!

Since we have them all in stock, we can immediately start the repair. The old pump is removed and after additional loosening of a number of peripheral issues, the new hydraulic pump fits the Iseki TL 1900. We can therefore conclude that even for an inexperienced person the changeover takes no more than 30 minutes.

After completely securing the hydraulic pump, we start the tractor. Immediately after starting, we hear that the pump starts up and the engine starts to run heavily. As if the hydraulics cannot be pumped around.

For your information: The plungers are a known problem when the hydraulics are not working anymore. Known characteristics; slow lowering of the linkage or complete blocking of the hydraulic oil! Many well-known tractors which have this problem are Iseki TU1400, 1500etc. Also other brands like Kubota or Yanmar can have this problem. This is purely due to contamination in the hydraulic oil or line.

After that everything was assembled as it was and again the tractor did not function and the hydraulic pressure built up. Then it occurred to me that perhaps the other mechanic had made a mistake when fitting the plungers. So we mounted them the other way round. Everything was reassembled and, by a miracle, everything worked again.