Bobcat bucket cylinder disassembly wrench

[cathead]

The bucket cylinder became droopy all of a sudden so had to find a way to take it apart and have a look at the inner workings.
The aluminum end cap on the cylinder has two quarter inch diameter holes for disassembly but one needs a specialized
tool to remove it. I made up an adjustable tool with 1/4 inch pins and it worked very well for the job. As it turned out the
nut that holds the piston has come loose causing the problem. Not having a 42 mm socket, I tightened the nut with a
hammer and a punch without doing much damage to the nut. I will have to disassemble the cylinder once I get the correct
socket and tighten it properly. For now, it is working just fine. I suppose it would be prudent to install the new ring and seal
kit while it is apart.

Here are several photos of the tool and one of the end of the bucket cylinder.
The pins were made of 1/4 inch diameter material, some pretty hard stuff...

 

[Cadillac]

I just had this same problem on a machine at work. I can’t explain how a locking pinch nut comes loose on the rod inside the cylinder and the rod end doesn’t rotate just pivots????
You had much better luck my cylinder had a recessed snap ring holding the cap and the snap ring was so corroded to the aluminum cap that the holes in the snap ring just broke off. I tried walking the ring out but was to stubborn so had to buy a new one.

 

[john.k]

Ever seen the piston nut come adrift and then get speared by the rod backwards?....Seen that a few times ...makes a mess.........One time a piston nut on a D9H blade lift ram wasnt fully tightened ,ended up speared backwards ......very expensive mess........the business owner sacked everyone in the workshop......including me.

 

[cathead]

Ever seen the piston nut come adrift and then get speared by the rod backwards?....Seen that a few times ...makes a mess.........One time a piston nut on a D9H blade lift ram wasnt fully tightened ,ended up speared backwards ......very expensive mess........the business owner sacked everyone in the workshop......including me.

Thanks for the interesting post, John. That gives me good incentive to tighten my Bobcat bucket cylinder nut properly. It's fine
thread almost an inch in diameter so guessing it would take 100 foot pounds or more to tighten it... I have the gasket and
ring kit and I see that it comes with a new nut.

 

[cathead]

The saga continues.................

A mechanic friend was nice enough to lend me a 3 foot bar and a 1 and 5/8 inch socket so I had to disassemble the cylinder again to
if nothing else tighten the nut. The one inch fine thread requires 230 to 250 foot pounds of torque so I was happy to have the 3 foot bar.
Removal of the piston nut was quite easy as it had already started to work loose after an hour of heavy excavating work. I decided to
replace the inner sleeve seals while it was apart and the kit was already in my possession. That part was quite uneventful. The plot
then thickens... It turns out that the nut supplied with the kit went on the threads slightly more loosely than the original and was just
a standard nut, not the self tightening like the original. To top it off, as I spun the nut on the threads, it was apparent that the nut wasn't
exactly true as it went on. My best option was to use the old nut but apparently it was a 42mm nut, not fitting the 1 and 5/8 inch socket
at all. I resorted to filing off by hand a thousandth of an inch or two so I could pound the socket onto the nut and reassemble the cylinder.
The out of spec nut would have been the easy way to reassemble the cylinder but in the long run may have caused fluid leakage and
likely would have cocked the piston slightly causing more problems in the future. As it turned out, the bucket cylinder is back together
and working fine now. I don't know how tight the nut is but I put on all the torque I could muster with the 3 foot socket handle. I could see
the bar bending with the final reefing so I have to believe it is tight enough.