Backhoe jinma backhoe hydraulics

[denzman]

Does someone know where to get cylinder parts for jinma backhoe? Cylinders will not hold pressure and are weak. Stabilizers will not stay up. Thanks

 

[Bob Rooks]

Welcome to TBN. :welcome::welcome:

One of the places you can get replacement parts is Circle-G Tractor. What year/model is the backhoe, and did you buy it new?
Do all of the cylinders seem "weak" or is it just the stabilizer cylinders?

 

[denzman]

Welcome to TBN. :welcome::welcome:

One of the places you can get replacement parts is Circle-G Tractor. What year/model is the backhoe, and did you buy it new?
Do all of the cylinders seem "weak" or is it just the stabilizer cylinders?

Thanks for reply. Bought hoe back in 2004. Sat in storage since. Only ID I can find is Y 1 . Only large piston at top that curls the arm is weak, support cylinders bleed down and arms sink. Again Thank you

 

[Bob Rooks]

Thanks for reply. Bought hoe back in 2004. Sat in storage since. Only ID I can find is Y 1 . Only large piston at top that curls the arm is weak, support cylinders bleed down and arms sink. Again Thank you

The problem I had with my LW-6 back hoe is that the cylinder cup seals disintegrated from using synthetic AW-32 hydraulic oil. Bad cup seals will cause your symptoms - pistons leaking by. You may also have some cup seal debris stuck in your relief valve. It should probably be checked and cleaned. You will have to order seal kits by cylinder size. Seals should also be available from your local hydraulic shop, who can also rebuild the cylinders.

 

[Johnny P]

The problem I had with my LW-6 back hoe is that the cylinder cup seals disintegrated from using synthetic AW-32 hydraulic oil. Bad cup seals will cause your symptoms - pistons leaking by. You may also have some cup seal debris stuck in your relief valve. It should probably be checked and cleaned. You will have to order seal kits by cylinder size. Seals should also be available from your local hydraulic shop, who can also rebuild the cylinders.

Hello Bob, hope you are well and avoiding Corvid19. Sorry I'm not technically offay with some of the terms for the parts on my backhoe. My ram disconnected itself from the "eye" due to the threads rusting. Can you suggest a repair? Also can you tell me what sizes the nuts and threads are on the inlet hoses? I live in France and have difficulty in getting spares for my Jinma tractor and attachments. I may need to get a new cylinder with standard fitments/thread sizes. Are there any adapters that you know of that will convert from Chinese threads to a more conventional thread?

Thanks John

 

[Troysie]

Hi John
I had the same thing happen to my JW03 boom cylinder, I very carefully welded it, by being careful I mean to not over heat the rod and also be sure things are aligned so the pin will go through easily, I have put approximately 50 hours on hoe since welding the piston and it has worked fine with no seal issues.

Troy

 

[Johnny P]

Hello Troy,

Thanks for that. I did think of that but I may have to get somebody to do it for me. I have a welder and have threatened to use it many times but never have. It would be my first attempt, after a little practice of course. On mine there was an Allen screw on the "eye" part and a slight indentation on the threaded end of the ram. I tried to unscrew this Allen screw but it rounded the corners. I drilled it out, rethreaded it and put a bolt to tighten it all together. Unfortunately it didn't work for long. I wondered if by drilling right through and putting a strong bolt through would work.

John

 

[Bob Rooks]

I wondered if by drilling right through and putting a strong bolt through would work.

Bear in mind that any material removed will also serve to weaken it. I recommend welding it like Troysie suggests, but if you won't I suggest installing a roll pin. If you have the room install a double roll pin. If you will be pulling against the roll pin or bolt because the threads aren't holding then your only options are weld or replace.

 

[Bob Rooks]

Are there any adapters that you know of that will convert from Chinese threads to a more conventional thread?

The hydraulic fittings on the cylinders are 14mm x 1.5 O-Ring Face Seal (ORFS) The fittings are not specifically Chinese. ORFS fittings are widely used throughout the industry. Tommy at Affordable Tractor Sales used to sell the 14 mm & 18 mm adapters to convert to JIC fittings. You can also make your own very inexpensively if you can weld and have a lathe, or you could take the idea to a machine shop an have them whip out a bunch.

 

[Johnny P]

The hydraulic fittings on the cylinders are 14mm x 1.5 O-Ring Face Seal (ORFS) The fittings are not specifically Chinese. ORFS fittings are widely used throughout the industry. Tommy at Affordable Tractor Sales used to sell the 14 mm & 18 mm adapters to convert to JIC fittings. You can also make your own very inexpensively if you can weld and have a lathe, or you could take the idea to a machine shop an have them whip out a bunch.

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Thanks for the replies Bob.