3-Point Hitch 3-point Hydraulic cylinder has flow by

   / 3-point Hydraulic cylinder has flow by #1  

Ben755

Bronze Member
Joined
Apr 13, 2014
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64
Location
Tx
Tractor
Yanmar FX28D
My FX28D needs o ring replacement on the 3-point hydraulic lift piston. I'm somewhat reluctant to tackle this job myself as I'm not sure as to what I might be getting into. The hyd lift breakout drawings for the FX28 are similar to those for the YM series tractors. However, the service manual for the FX28 is all in Japanese. Specifically, I have concerns about removing the piston from the cylinder and detaching the ball shaped ram shaft behind it. (not sure how this shaft mates to the splined rock shaft that rotates the lift arms). Apparently, the panel below the seat and the seat itself, including the panel it rests on must be removed just to get access to front cover plate of the cylinder. I'm also noting that the hydraulic pressure line on the cover plate is metal and rigid. Does the rock shaft or cylinder require removal ? If so, I won't attempt the job.
 
   / 3-point Hydraulic cylinder has flow by #2  
The piston is not actually connected to the rod (the ball end just rests in a socket in the piston) so you could, in theory, just remove the cylinder head and use a suction cup or similar and pull that piston out. I've never tried it but that would certainly make the job much easier.
 

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   / 3-point Hydraulic cylinder has flow by
  • Thread Starter
#3  
"the ball end just rests in a socket in the piston".....I'm confused, the drawing is showing the ball end part of the shaft facing away from the piston. I just talked to a guy that has a repair shop and works on 3-point hydraulic systems all the time and he says that he has always had to remove the rock shaft before removing the piston from the cylinder.
 
   / 3-point Hydraulic cylinder has flow by #4  
"the ball end just rests in a socket in the piston".....I'm confused, the drawing is showing the ball end part of the shaft facing away from the piston.

I guess they are both ball ended but I mean the other ball end- the one that slides up into the piston.

I just talked to a guy that has a repair shop and works on 3-point hydraulic systems all the time and he says that he has always had to remove the rock shaft before removing the piston from the cylinder.

That is the way I have always done it also but it seems possible that you could pull the piston out of the cylinder from the front if the piston was not stuck in there too tight- especially if the oring was shot. There might be a lip of rusty stuff near the end that you might have to hone away before you could pull it out though.
 
   / 3-point Hydraulic cylinder has flow by #7  
Cannot tell for sure, is that a plate on the rear of the lift assembly like this old 2000?

According to the parts book there is not an opening back there- it is solid. I don't have one apart to confirm though. Might be worth a shot.
 
   / 3-point Hydraulic cylinder has flow by
  • Thread Starter
#8  
Here is where us DIY guys get pay back on the cost of a workshop manual. I am sure the Yanmar dealer can get you one for your model. My Kubota WSM has made its cost over many many times.

Ron

Cost of the manual is not an issue. If an English version existed, I would certainly try to obtain it. The Yanmar FX series was marketed in Japan only, and the service manual was printed only in Japanese.
 
   / 3-point Hydraulic cylinder has flow by #9  
it does require removal. and it is heavy I use an engine hoist to lift the unit off. It's really not that bad of a job, but takes time, you need to take all the fenders and sheet metal off the back of the tractor just to get started. I have 2 fx 28's and have done both.
 
   / 3-point Hydraulic cylinder has flow by #10  
I took quite a few pictures when doing it the first time. if you decide to move forward let me know and I'll try and dig some up.
 
 
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