yanmar 2002d hydraulic lift

Another project probably not needed but just wanted by me so here tis. My lift slowly leaks down so I decided to order all the o-rings and gaskets to go through it. The way the 2002 lift works it constantly raises it if it drops a minute amount it will pick up a minute amount. Remember all Yanmars are not created equal and this one is quite different than the 1500, 1700, 2000, etc. Took sort of step by step pictures. I have cleaned up and put everything back together except I did not receive the lift piston o-ring. I ordered it this afternoon from Crown products. They indicated it might be in tomorrow. Hoyes did not have it and indicated it could be a week or so to get it. Many of these Yanmar o-rings are Japanese standard and not readily available just anywhere. Enough blah blah blah. Will be glad to answer any questions if I can.

Might just state this one thing. The complete lift assembly as you see removed I would estimate weighs around 100lbs. There is nothing there but steel. Took a couple of pictures looking down in the differential housing and pto assembly. I did lightly hone the lift cylinder and could see noticeable wear on the o-ring.

winston1 said:

I did lightly hone the lift cylinder...

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Did you use an engine hone, or something else? I've always wondered what the factory finish is on a new tractor: polished to a mirror, roughed up like an engine, etc.

yep thats a job i need to do on mine. it leaks down and annoys the crap out of me. when the pump starts whistling its time to pull the lever up and lower it till its quiet.

I used this Sunnen model AN hone with fine stones. Just used it very briefly. Not a very good picture.

Neat 1500 said:

yep thats a job i need to do on mine. it leaks down and annoys the crap out of me. when the pump starts whistling its time to pull the lever up and lower it till its quiet.

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Same here Neat. I'm planning on it being a fall project. Going to get my one big order into Hoye.

Thanks Winston for taking some pictures. Always good to see these tractors apart for future reference. The manuals just don't show enough detail.

i want to do this to my 2000 one day. And yes that is not a ym2000! That top is huge!! looks to be 2x the size of a ym2000.

Sorry about the double thread. I got my o-ring today, got it installed and have tested. Lift stayed at whatever position I put it at and never leaked where it had to pick up a little. I parked it with my finish mower in the up position about an hour and a half ago and best I can tell it has not leaked down one smidgen. I'm tickled pink.

For what it is worth the lift assembly would not have to be removed to change the piston o-ring. All one has to do is remove the 4 bolts holding the stop valve assembly and that cover. That cover comes off and the lift piston is not attached to anything. Just floats in there. I believe you could get it out with a big magnet.

winston1 said:

For what it is worth the lift assembly would not have to be removed to change the piston o-ring. All one has to do is remove the 4 bolts holding the stop valve assembly and that cover. That cover comes off and the lift piston is not attached to anything. Just floats in there. I believe you could get it out with a big magnet.

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Now that is $100 worth of info thanks! nice write up btw very complete.

I knew it floated in there, BUT here is what i have been thinking. I will try this method at some point, and let you know it it works. I have the oring. But i dont think it will. The piston rides on the shaft or rod that pushes it. Its just a rounded end of a rod, like a broom handle, the piston is domed on the back and they just fit togeather. The problem i see is once the piston is pulled free from the rod it may flop down in the cyl, and the piston may not seat back ontop of this rod fully therefore not being able to be assembled correctly.

Question, is the pison all the way foward with the 3pt in the lowered position?

That's good thinking Clemson. I believe if the piston could be pulled out it would have to be all the way back when the arms are down logically. Now another question is whether there is a chamfered area at the bottom to the piston to allow it to engage the rod the first time or is the rod semi rigidly mounted somehow or has a stop of sort to keep the rod basically centered? Winston may have a paypal account we send into for all these answers. :laughing: