YM226D Power Steering Rebuild

California · Aug 4, 2016

Smoody said:
I am taking the power steering cylinder to that shop for the owner to look at it and tell mW if he can repack it. He said he has experience working on those from many yanmars some 20 year or so ago. If it turns out I will give you guys his contact info.

If he proves to you he knows what he is doing ... I'll send him mine to re-seal too. I didn't know there was anyone left who could do this.

Smoody · Aug 4, 2016

California said:
If he proves to you he knows what he is doing ... I'll send him mine to re-seal too. I didn't know there was anyone left who could do this.

I sure hope he can, I told him how impossible getting parts or the aluminum casting cover is, he seemed confident the orings inside it are standard sized, this place is about 30 miles from me, glad I found it. Hopefully it works out, I have nothing to lose as its leaking way to bad to use it now

clemsonfor · Aug 4, 2016

That's good on both accords

clemsonfor · Aug 4, 2016

California the tractors are not that old. I'm sure there is a handfull of folks all over that can do it. Granted there all probably 50 to 60 on the younger side but you just have to find them.

I don't even think they need to be one who worked on yanmars cause hydraulics are hydraulics, this is a fairly simple thing. But you can't find a current part swapped mechanic that needs a computer to start him down the right road to fix it.

California · Aug 4, 2016

I'm not convinced there are many techs that have even seen this rare PS dealer-installed option. It wasn't widely used and I haven't found any other application for it like automotive, forklift, etc.

My particular concern is how to hold it while applying maybe 200 ft lbs of torque to the cylinder end cap, and not distorting or crushing what looks to be a delicate aluminum casting. Aside from that issue I could repair it myself but I can't figure out how to grasp it without damage. I tried unscrewing the end cap with as much force as I dared, I think 15" crescent wrench, and it wouldn't budge. The small and large cylinders' end caps are so close I can't get a box wrench on either. The small end cap won't turn until the large one is removed and out of the way. If they had designed it with more clearance then it would be trivial to open the smaller, control cylinder for the periodic maintenance it seems to need.

There was an old thread where a dealer said he had repaired these, and he described it as simple but taking a long time. I have the parts/overhaul manual for it but there's no mention of how to hold it while working on it.

Its more valuable to me to have functioning power steering. While it isn't ideal, I can live with a little dribble.

clemsonfor · Aug 4, 2016

I need to go back through and look at pics of this thing. Can you use a special thin wrench or grind one down? If it takes 200 lbs of force probably bend out a thin low profile wrench.

clemsonfor · Aug 4, 2016

And California I know what you mean on the service manual. I have the ym240 yanmar (produced by them)service manual. No where did it mention the brake shaft seal removal. Now that's fairly straight foward but it's odd that the process is not mentioned or even the assembly that's on the side of the transmission that holds the bearings for the brake shaft in much detail.

I read the girl and her tractor post hoye has on their forum, but I was going to tear into it anyway...just strange.

Smoody · Aug 5, 2016

Well, I had the Hydraulic Shop look at it, the guy said he is pretty sure he could repair it, however I believe I scared him out of it telling him how rare or impossible finding those aluminum casting parts are, he will attempt it, BUT he is not responsible for it if he breaks any of it trying to remove the large cylinder, same as California has clearly shown the concern over putting the required force to break it loose. I am not sure I want to risk it.

I also was able to measure a drag/steering rod from a YM220, it is 25 1/2" long with a slight bend 5" up the rod on the axle side. I believe I can get someone to make me one of those with some steel tubing and welding a threaded coupler to each end for the tie rod/ball joint threaded stud to screw into.

I was reading over the Actuator Assembly diagram and #2 says Remove the sub assembly, Im guessing that is #15 in the diagram, but do not disassemble beyond that point, so is the #11 o ring closest to the weep/air hole the sole culprit here that needs to be replaced, what about the other o ring deeper into the sub-assembly (#15). I made some annotations on the photo.

clemsonfor · Aug 5, 2016

SoAK that whole assembly in transmission fluid and acetone, and heat that thing up and try to get the nUT off then.

California · Aug 6, 2016

Smoody said:
I was reading over the Actuator Assembly diagram and #2 says Remove the sub assembly, Im guessing that is #15 in the diagram, but do not disassemble beyond that point, so is the #11 o ring closest to the weep/air hole the sole culprit here that needs to be replaced, what about the other o ring deeper into the sub-assembly (#15). I made some annotations on the photo.

I think that #15 assembly is factory-calibrated for neutral steering effect when you aren't turning the wheel. I definitely wouldn't disassemble it.

I would replace only the O-ring nearest the weep hole. Only in case the one deeper into the mechanism is visible, would I replace it, because I think getting to it will disturb the left/right steering balance.

In that diagram the weep hole points down. I wish mine did, it squirted upward all over the side of the tractor until I put a 'diaper' (inner tube segment) over it to change the squirt to a downward dribble. The volume that comes out isn't much, less than the volume of an aspirin tablet for every left turn, but it made a real mess over several days.

Smoody, good luck with this.