226D Won't Move

hoffmanfarm · May 12, 2019

My Yanmar 226D moves extremely slowly. the FEL and 3PH work but are also very slow. The PTO seems to spin just fine. I should mention that the gasket between the transmission case and rear axle case leaks hydraulic fluid. Tractor moves better when hydraulic fluid level is very high. If I just add enough so that it stays in the dipstick's hashed area, the FEL works barely but the tractor will not move at all.

I have read every post I can find online that has anything to do with this problem and researched quite a bit in the service manual.

Here is what I have tried so far:

-drained hydraulic/transmission fluid and refilled with new fluid
-removed and cleaned hydraulic screen filter
-replaced hydraulic cartridge filter
-removed and checked main relief valve and delay relief valves (both springs are 1mm shorter than specs)
-put pressure gauge on hydraulic test port on regulator case and started the tractor, put it in every gear, released the clutch. It did not show any pressure at all. Ever. Zero.

Still not working.

Any ideas would be greatly appreciated.

careyo63 · May 12, 2019

I have nothing on a 226. But what you said on the test port. No pressure Zero Zilch which tells me something maybe clogged. Look on you Manual and a 226 may have or does have Filter/Screen on the Valve Body of the Transmission. The valve body regulates were the Hyd. fluid goes in the Trans.. It almost sounds like that screen is clogged. I have heard of it happening before on a Power Shift. Just a guess I have nothing. I'm going to see if I can find it on another model so your know what I'm saying. But something stinks!!! Pin sheared or worn on the Hyd. pump and barely or just enough to somewhat spin the pump?? No pressure or very little so see what I'm saying....

California · May 13, 2019

A Powershift Yanmar has two un-related hydraulic pumps: The usual one on the engine to raise the 3-point, plus another pump inside the transmission that engages its internal clutch packs. The transmission one only pumps after you select a gear and let the clutch out to spin the transmission input shaft. So ... I'm not sure this helps clarify what's happening.

Likely when neither pump works well it indicates both pumps are starved for fluid.

The PTO is a direct mechanical connection from that transmission input shaft back to the PTO gears. So if the PTO spins, this shows the engine's clutch and the little driveshaft from the clutch back to the transmission are ok.

winston1 · May 13, 2019

What fluid are you using? Are you using the correct micron filter?

careyo63 · May 13, 2019

I came across a damaged Pump Shaft on a Power shift 175 I have. I believe it was. It was late for me. And When that screen gets dirty. Like I mentioned The internal pump can't get fluid to it, Starving for fluid .......

hoffmanfarm · May 13, 2019

winston1 said:
What fluid are you using? Are you using the correct micron filter?

I'm using Super S Super Trac from Tractor Supply. It says it's tractor hydraulic and transmission fluid. The filter is a Baldwin B2 which I was told by the salesman and Walt'sTractors.com that it cross-references directly.

Jtullis13 · May 13, 2019

Maybe your relief valve is stuck/broke?? Maybe take your pressure gauge off and try to operate with it off just for a brief second or two and see if any fluid comes out. If not there might be your problem. If you are not getting that return fluid you are starving your pump and would explain why everything is very slow. Or your hydraulic pump could have went, but it doesn't sound like that. I would check your relief valve.

careyo63 · May 13, 2019

I will say setting the Relief valve off made a loud noise there was no way you didn't hear it. Done it before. No mention of that happening. And that would be about the only way to get dirt in it so it doesn't close and seat properly all the way. It may have happened but that's why I didn't go there. And then starve the Trans. pump is a major No No. I'm with you though and see what your saying so don't get me wrong. It could be and have to try and give our advice on getting the Org. poster up and going. Which is a lot easier if we was there with the tractor.

winston1 · May 13, 2019

Very puzzling that loader and 3 point are slow and powershift is slow. Both unrelated pumps. Sure point toward dirty fluid or strainer/filter. Although the power shift fluid does not go through the spin on filter. The powershift fluid does go through the strainer. Trouble shooting section also lists a possible cause as damaged O-rings for suction pipe.

hoffmanfarm · May 13, 2019

Thanks for the replies. I double checked the relief valve today and couldn't see any problems. I'm starting to think the slow FEL is a separate problem than the slow transmission. I'm going to split the tractor and take a look at the power shift pump. I'll keep you guys posted.