I have a leak between the flow control valve (the valve with the big adjustment knob on it underneath the seat) and the housing it mounts to. In looking at the parts diagram it looks like there is an oil seal there. I removed the four bolts from the flow control valve and it only slid forward about 1/8" inch. Before I slide a prybar in the gap and try to work it out, is there anything else I should be doing or removing or to release it? I am assuming the cylinder just slides forward but is a tight fit, but really have no idea. Thanks for any advice!
Hydraulic Flow Control Valve Leaking - Jinma/Nortrac 254
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piper184
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It would appear that there is an o-ring that seals the cylinder to the valve housing but there is nothing shown between the housing (called a cap) and the tank body. One would think that there needs to be a gasket between them.
Have you completely removed the adjusting knob and associated parts below it? If I remember correctly, there is a set screw that locks the knob from rotating. You might have to take that all the way out so that the adjuster can screw out the top. I think that the bottom of the adjuster might be catching on the groove at the base of the cylinder. There is also a bolt on the right side of the cap that might be holding onto the cylinder too.
I would be inclined to remove everything I can unfasten before going any farther. Hopefully someone that has actually had this apart will chime in.
Take pictures so you can post how it is done.
Have you completely removed the adjusting knob and associated parts below it? If I remember correctly, there is a set screw that locks the knob from rotating. You might have to take that all the way out so that the adjuster can screw out the top. I think that the bottom of the adjuster might be catching on the groove at the base of the cylinder. There is also a bolt on the right side of the cap that might be holding onto the cylinder too.
I would be inclined to remove everything I can unfasten before going any farther. Hopefully someone that has actually had this apart will chime in.
Take pictures so you can post how it is done.
Appreciate it piper184! I did find the below direction on this thread 3-Point Hitch - Farm Pro (Jinma) 2425 hitch will not stay up .It seems like the piston should just pull out but it doesn't seem to want to. Hopefully someone who has done it before will chime in and give me the courage to pry harder.
"Steps to rebuild the hydraulic piston -
1. Drain Fluid
2. Remove Gear Shifter Cover and Arms (you will need to do this to get the cylinder out, its in the way). (See Pic)
3. Pull out the cylinder. (See Pic)
4. Remove the piston from inside the cylinder, on mine it slid right out, the rings were bad, but if the rings have a good seal you will need to tap it on something while holding the cylinder upside down to get it to come out enough to get a grip on it.
5. Replace the ring and nylon washers (See Pic)
6. There is a arm that goes into the cone side of the piston which faces the rear of the tractor) this will drop down when you pull the cylinder out. You will need to pull the plate off the back of the tractor where the 3PH top arm connects and when you put the cylinder back in reach in and put the arm up into the cylinder cone.
7. Replace the 3PH plate, the cylinder and the Shifter and cover. Make sure the shifters line up with the linkage arms. This was not too difficult but took my several tries to line them up as well as the gasket. I had to put the cover on and get the tractor in Neutral in order to line up the shifter with the linkage arms, there are three arms, one for High and Low, and the other two are for Reverse and first gear, the other for second and third gear. You can see them in the picture.
I hope this helps anyone with the same issue I was having. It was much easier to do than I thought. I wish that I would have tried it myself first and saved the $277 that the John Deere dealer charged me to look at it and not find anything wrong."
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"Steps to rebuild the hydraulic piston -
1. Drain Fluid
2. Remove Gear Shifter Cover and Arms (you will need to do this to get the cylinder out, its in the way). (See Pic)
3. Pull out the cylinder. (See Pic)
4. Remove the piston from inside the cylinder, on mine it slid right out, the rings were bad, but if the rings have a good seal you will need to tap it on something while holding the cylinder upside down to get it to come out enough to get a grip on it.
5. Replace the ring and nylon washers (See Pic)
6. There is a arm that goes into the cone side of the piston which faces the rear of the tractor) this will drop down when you pull the cylinder out. You will need to pull the plate off the back of the tractor where the 3PH top arm connects and when you put the cylinder back in reach in and put the arm up into the cylinder cone.
7. Replace the 3PH plate, the cylinder and the Shifter and cover. Make sure the shifters line up with the linkage arms. This was not too difficult but took my several tries to line them up as well as the gasket. I had to put the cover on and get the tractor in Neutral in order to line up the shifter with the linkage arms, there are three arms, one for High and Low, and the other two are for Reverse and first gear, the other for second and third gear. You can see them in the picture.
I hope this helps anyone with the same issue I was having. It was much easier to do than I thought. I wish that I would have tried it myself first and saved the $277 that the John Deere dealer charged me to look at it and not find anything wrong."
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piper184
Gold Member
Well, that raises some questions. The parts books show the cylinder and the cap being two different parts but the photos from that post show it coming out as one piece.
Is yours leaking between the cap and the tank or is it leaking around the adjuster screw and just running down the cap? There is an o-ring on the adjuster screw that you should be able to replace without taking the cap or cylinder off. Mine leaks a little at the adjuster but not enough for me to try and fix it (yet).
I think I would rather pull the seat and tank off of the rear end than take the shifter and top off of the transmission. It is heavy so it is best to use an engine hoist. I've had mine off to work in the differential area. If done carefully, you only have to drain the hydraulics and not the diff/trans.
Is yours leaking between the cap and the tank or is it leaking around the adjuster screw and just running down the cap? There is an o-ring on the adjuster screw that you should be able to replace without taking the cap or cylinder off. Mine leaks a little at the adjuster but not enough for me to try and fix it (yet).
I think I would rather pull the seat and tank off of the rear end than take the shifter and top off of the transmission. It is heavy so it is best to use an engine hoist. I've had mine off to work in the differential area. If done carefully, you only have to drain the hydraulics and not the diff/trans.
I got the courage to pry a little harder and was able to walk the cylinder out, just like the photos above show. The o-ring came out with a tear in it so I hope a new one will fix the leak. To answer your question, mine is leaking between the cap and tank. The adjustment screw is not leaking. Thanks again!
piper184
Gold Member
Thanks for posting the update. Good job!
Does the cap separate from the cylinder?
Does the o-ring seal between the cap and the cylinder or the cap and the housing?
Did you have to remove the top of the transmission for clearance?
Post pictures if you can.
Does the cap separate from the cylinder?
Does the o-ring seal between the cap and the cylinder or the cap and the housing?
Did you have to remove the top of the transmission for clearance?
Post pictures if you can.