Hydraulic cylinder refurb

Johnny P · Mar 22, 2009

Hello,

Is it possible to strip, refurb and rebuild a hydraulic cylinder on JW03 backhoe? Is it something you can do yourself or does it have to be done by a specialist? Any pointers please.

Thanks Johnny P

Bob Rooks · Mar 22, 2009

Most definitely. I did it several times on my old LW-6 (same as JW-03).
I assume you mean to disassemble the cylinder and replace the seals because that's about all you can do except maybe hone the cylinder tube. Straightening and refinishing rods is best left to a hydraulic shop.
Cup seals are readily available from various tractor dealers and some hydraulic shops.
You may find as I did, that there were different cylinders used on the hoes. Some had a split retainer end, and some had a screw-on end with a locking set screw.

Good luck.

Johnny P · Mar 24, 2009

Bob,

Thanks for that. I do not want to strip the cylinder down if I can help it. The reason for asking is that I disconnected the two hoses to the cylinders and nether one had o rings in them. I wondered if they have been sucked into the cylinder. This is all to do with the failure of my backhoe. See my threads dated, 2/222/2009, 2/23/2009 and 3/13/2009.
Please see attached photograph and could you tell me which part is unscrewed. Is is part A the inner end or Part B an outer part of the cylinder(don't think it's this part). Do the holes C play any part in the dismantling of the cylinder.

Thanks

Johnny P

Johnny P · Mar 24, 2009

Bob,

Here is the photograph. Sorry.

Johnny P

SPIKER · Mar 24, 2009

JohnnyP

the seals may have stuck to the hose end or even popped off when you removed the hose end. If they were not leaking them the seals were there when it was running but there should be no way to have those o-rings sucked into the hyd cylinder. rebuilding them is only needed if they are leaking out of the rod ends, (or bent/damaged.)

Mark

kennyd · Mar 24, 2009

What kind of fittings are they? Not all types use O-Rings.

Bob Rooks · Mar 25, 2009

Part B appears to be the female threaded boss that is a weldment part of the cylinder tube. This is yet another new type to me.
Part "A" screws into part "B" and has an O-ring seal just inside that seals the threads. The hole "C" could be a pin spanner wrench hole if there is two of them - also there could be set screws deep within the pin holes (the set screws need to be removed in order to unscrew part "A".) - also check around the periphery of part "B" for set screws.

As Spiker said; You probably misplaced the O-rings. It would be virtually impossible to "suck" an O-ring into a cylinder. There is always pressure on both sides of the piston, coming and going. However, a cylinder can still be faulty and have no external leaks. The piston cup seals can be blown and the cylinder will not function under load.

Kennyd: The Chinese hoes have 18mm x 1.5 ORFS fittings.