bjr
Veteran Member
Can I remove the 3 pt piston from under the seat without removing the whole lift box? I need to replace the piston oring and would really like to do it as simple as possible. bjr
'02 Jinma JM 354 lift piston removal?
- Thread starter bjr
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quicksandfarmer
Elite Member
If you have the same lift box as my 2007 354, yes. I have the 300HY lift box, the name is cast into the side.
The lift cylinder comes out toward the steering wheel. You have to disconnect the pipe going to the rear single remote, and then there are four bolts that hold the front plate on. Those are on very tight. They cylinder and piston come out together, in order to get them out you have to take the top cover off of the gearbox, six bolts. (The gearshift lever is in the way).
To get the piston out of the cylinder there is a 6mm tapped hole in the back of the piston. I put a 6mm bolt through a piece of plumbing strap and fastened it, and then pulled it out with pliers.
The lift cylinder comes out toward the steering wheel. You have to disconnect the pipe going to the rear single remote, and then there are four bolts that hold the front plate on. Those are on very tight. They cylinder and piston come out together, in order to get them out you have to take the top cover off of the gearbox, six bolts. (The gearshift lever is in the way).
To get the piston out of the cylinder there is a 6mm tapped hole in the back of the piston. I put a 6mm bolt through a piece of plumbing strap and fastened it, and then pulled it out with pliers.
Well after a careful online parts study (online Jinma tractor parts and mostly oring standards) I went to the Hydraulic store and got the wrong orings. It boils to New style/Old style and when I finally got home and reviewed my OEM parts book and went out looked at the tractor I have the Old Style. No front cover plate. Apparently I do have remove the whole lift box off becuase there's stud/ nut on the bottom side of the box and all three of the orings I purchase are for the new style lift boxes. I need the AS568-335 oring 2.725" x 0.210". The oring standards are Metric/US inch converted. I find that kinda refreshing, now if my local suppliers have one and will be open on the Friday before the 4th of July. I'll probably have to let the repair job go till next week as I have a small baling job coming up, so, I can't tear down the tractor and wait on parts. "It's a good thing there are two kinds of luck or I just wouldn't have any" bjr
quicksandfarmer
Elite Member
Before removing the lift box I would check with Tommy at Affordable Tractor, he'll know if there's a way to get the cylinder out without taking the lift box off. Usually that's the case. Some go out the front, some out the back and some under the seat.
Update: I was able to get the oring yesterday and proceeded to tear down the lift box. It was 105 deg. and could only get an hour or so of work done at a time and then stop to cool off. Finally got box off and gutted except for rocker shaft. A LOT OF PARTS. There is a mile of difference between the "new style" and the "old style". There was two orings laying in the bottom of the box after removing the cylinder and two springs. The springs I kinda got where they may go but the orings I haven't a clue. Maybe, they orings go around the thru the case bolts/studs that hold the cylinder on? The piston oring doesn't show any damage or real wear, so, all this was probably for not. I'm just guessin' that maybe the pumps wore out, now. Tell me if there is orings around the cylinder to case bolts please? bjr