HYDRAULIC CYLINDER REBUILD

J_J · Oct 26, 2003

HAS ANYONE REBUILT THE LIFTING CYLINDERS ON A PT ?
MINE ARE LEAKING , SO I ORDERED A KIT FOR EACH, BUT THEY CAME WITH NO INSTRUCTINS. THE QUESTION IS , IS THIS A STRAIGHT FORWARD COMMON SENSE KIND OF THING , OR IS THERE A CERTAIN ORDER AND DIRECTION THE O RINGS HAVE TO GO ?
NEXT QUESTION IS HOW TO GET ALL THE AIR OUT OF THE CYL ? IS THERE ENOUGH OIL FLOW TO SEND THE TRAPPED AIR BACK TO THE TANK WHEN THE CYL IS CYCLED AND HOW DOES ONE KNOW WHEN ALL THE AIR IS OUT. J.J.

toy · Oct 27, 2003

I have not rebuilt one of their cylinders, nor seen what is in their kit, but if there is a ceramic disc in the kit or ithere is one where the o'ring goes pay attention which side of the o'ring the the discs are on and replace them in the same order. Is the o'ring a regular o'ring or does it have something different. I have seen some cylinders with a cup type gasket on them, getting them back in the barrell of the cylinder was hard . We had to use a worm clamp on the cup to squeeze it in enough to start it in the barrell., it worked like a charm. But ,I haven't had one of these cylinders apart so I don't know what it would be like to rebuild one. If you rebuild yours let us know how it goes. Pt has an exchange plan for their hydrolic jacks, 70% list price I think.

Bob999 · Oct 27, 2003

I have not rebuilt a cylinder but there is a page in my PT Manual titled "Seal Kit for C026 Series Cylinders" That lists the parts in the seal kit and shows where they go.

If you don't have that page John Coxon (Sedgewood) has it posted on his web site Seal kit

wasabi · Oct 27, 2003

I've rebuilt a couple now. It is not tough. Just keep close track of how things are when you take the cylinder apart and carefully put it back together the same way, but with the new parts. (Caveat: this assumes the cylinder was put together right the first time). Would also suggest you "do the purge thing" a time or two after re-assembly.

J_J · Oct 31, 2003

I DID MY FIRST HYDRAULIC CYLINDER REBUILD TODAY, WENT FAIRLY EASY. I LEFT THE BODY OF THE CYLINDER HOOKED UP TO THE BOTTON PIN, RELEASED THE TOP PIN, THEN UNHOOKED BOTH HOSES, SO THERE WOULD NOT BE ANY VACUUM. UNSCREWED THE TOP OF THE CYL AND PULLED HARD AND SLOW, SO OIL IN THE CYL WOULD NOT SQUIRT EVERY WHERE. TOOK THE INTERNAL SECTION TO A CLEAN WORKING AREA. HAD TO REMOVE A LARGE NUT ON THE BOTTOM OF THE ASSEMBLY, SO ALL THE PARTS WOULD COME OFF THE ROD ASSEMBLY. IT WAS MOSTLY COMMON SENSE FOR THE O RINGS EXCEPT FOR THE WIPER FOR THE ROD. IT HAS TO BE PUT IN CORRECTLY . REPLACED OLD O RINGS WITH NEW, PUT OIL ON EVER THING, AND SLID THE ASSEMBLY BACK TOGETHER. SCREWED THE TOP ON , HOOKED CYL TO THE LIFTING ARM AND AND TESTED THE UNIT. WORKED GOOD , NO LEAKS. I HOPE ALL THE AIR IS PURGED FROM THE CYL.
I HAVE TWO MORE KITS, BUT I AM THINKING OF THAT OLD SAYING, IF IT AIN'T BROKE, DON'T FIX IT. WHAT SAY YOU.

J.J.

smartguyz · Oct 31, 2003

If it is as straightforward as you say, and the other units are NOT leaking, then I agree - keep things simple, keep the kits as spares, and leave well enough alone.

Sincerely,

Rob /forums/images/graemlins/grin.gif

MossRoad · Oct 31, 2003

I agree; if it aint fixed, don't break it.

J_J · Oct 31, 2003

THE LEAK THAT I FIXED WAS FROM THE ROD AREA AT THE TOP OF THE CYLINDER. THERE IS ONLY ONE O RING AND A ROD WIPER IN THAT AREA.
SOMEONE ONCE TOLD ME TO CHECK FOR AN INTERNAL LEAK, WAS TO RAISE THE LIFTING ARMS UP, WAIT ABOUT 12 HOURS, AND SEE IF ANY MOVEMENT HAD OCCURED. IS THAT A GOOD TEST. IF YOU KNOW THE CYLINDERS ARE GOOD , THE HOSES ARE ALL TIGHT, THEN THE VALVE MIGHT BE LEAKING.

J.J.

J_J · Nov 3, 2003

WELL, THE STATIC TEST THAT I DID FOR THE CYL AND VALVES, INDICATES THAT I STILL HAVE A INTERNAL LEAK. IN ORDER TO CHECK ONLY THE CYLINDERS, I WILL RAISE THE LIFTING ARMS WITH A LOAD , SURPORT THE ARMS WHILE I REMOVE SUPPLY HOSES TO THE CYL AND PLUG THEM. THEN I WILL REMOVE THE SUPORT FOR THE LIFTING ARMS AND WAIT TO SEE IF INTERNAL LEAKAGE OCCURS.

J.J.

smartguyz · Nov 3, 2003

I'm not so sure the leakage test you performed is really all that useful, or that things are in need of repair. Every tractor I have does the same thing - after several hours, the loader arms tend to drop. So long as it doesn't do it quickly, I don't see the big problem.

Guys, what do you think?

Sincerely,

Rob /forums/images/graemlins/grin.gif