hydraulic cylinder repair. Can't remove the gland nut.

Kernopelli · Sep 15, 2014

I have leaking seals on a backhoe cylinder and can not get the gland nut loose. This is the second time I've had to rebuild one of these cylinders and on the first one, the gland nut never came loose......I tried and tried and eventually took it to a local hydraulic shop that does most of the work for local mines and excavation contractors and they ruined the gland nut and still didn't get it out.

I can put enough pressure on the spanner that it will simply shear the pins off in the gland holes ( this is a heavy wrench with treated 1/4" pins). The nut is recessed so I can't get a pipe or chain wrench on it. I am at a loss! I have tried heating, turning both directions, tapping with a hammer and penetrant to no avail. The nut is aluminum and the barrel is steel. The nut has 2 holes for spanner pins, I am considering drilling 1 or 2 more holes and making a 3 or 4 pin wrench to get more "bite" on the gland.

Anyone know a secret or have a better idea than a wrench with more pins?

r8nger · Sep 15, 2014

Are you sure it's threaded? I've done some that have a spring or clip that you remove through that slot in the pic. If that's the case, you have to push the gland in to remove it.

J_J · Sep 15, 2014

Did you pull the wire retainer from the side?

Indygunworks · Sep 15, 2014

make a small screw driver small enough to fit under the retaining wire to provide a "ramp" for the retaining wire to ride up as it leaves the hole.

Are you able to move the gland even 1/8th of an inch either direction.... if so then the retaining wire is probably binding. I just had the exact same thing happen on a backhoe cylinder and it was a PITA but w/ one person holding the screw driving and prying and me turning the gland it eventually started moving just a tad and I was able to free it up.

I doubt yours is threaded... You might also try some penetrating oil into the retaining wire slot and let that soak in over a few days to help free it up.

Could the cylinder be under pressure?

Kernopelli · Sep 15, 2014

Thanks for the responses!

It isn't threaded.....or at least I don't think it is ( I've yet to get one apart). I have tried tapping the gland "IN" but it won't budge.

JJ: The "head" ( bent section sticking out of barrel slot) on the wire is too short to grab and pull, I tried pushing the wire on the previous cylinder that needed new seals and it simply broke the wire head off. I was under the impression the wire didn't really need to be pulled much, that it would feed out as the gland was turned. (?) Either way, I didn't have success with that method last time so I have not tried with this one. ( I tried using a small chisel to tap the wire forward, that is how I broke the "head" on last one).

Am I "able to move the gland even 1/8th of an inch either direction?" NO, the gland nut won't budge in either direction, if I could get it to turn at all, I'm sure I could get it out ( eventually). This thing is REALLY bound.

The gland is aluminum so I haven't tried to turn it with a hammer and punch. I tried that on the last one since I didn't have anything to lose after getting it back from the shop. It simply made a bigger mess of the holes in the gland nut ( hard to believe they could be messed up worse than the shop made them).

Also, no hydraulic pressure on the cylinder, the rod will easily move in/out by hand.

Only thing I can think to do is drill more and slightly large spanner holes and make a 3 or 4 pin spanner wrench....with only two 1/4" holes the spanner pins just keep breaking. Any other advice or "tricks" on getting it to loosen up?

Indygunworks · Sep 15, 2014

Kroil may be your best friend on this one. If you don't already own a can, then you need to pick one up anyways.

bigdeano · Sep 15, 2014

Can you look at a service manual to see how to get it apart, or call the manufacturer? Maybe there's a trick to it.

Leejohn · Sep 15, 2014

I'll tell you what I did on the last one I did. Got some flat stock drilled a hole a little bigger then the rod then cut it off center to leave some stock to driil and tab the size as the holes in the cover nut. After drilling and tabing to size I used allen head set screws for pins, they are hard. Then welded a long handle to the part I just made. The handle I welded on was at least 2 ft. long. Where you cut the metal off center it well not go over rod until you grind some on it.

farmallman1949 · Sep 17, 2014

Lots of penetrating oil, a large hammer, small screwdriver, and your spanner wrench should be all the tools you would need. First drown the thing with penetrating oil, then pull the rod all the way to the extended position and hit the gland firmly (not hard enough to distort the holes but hard enough to jar it into the cylinder tube), now take the screwdriver and gently work it under the retainer ring, and then try turning the gland. If this does not work wash rinse and repeat (not literally but just keep trying the process).