Pc35mr Blade cylinder gland nut getting tighter as I loose

[John V]

Howdy, I’m trying to reseal the blade cylinder on my Pc35mr-2 as the rod seal has blown and is pissing a leak. I managed to get the gland spinning with a hook wrench and a 4 ft cheater bar (manual says it’s tightened to about 500ftlbs). Thought the hard part was over. Not quite. After about 1 revolution, it’s getting harder n harder to loosen. Afraid I’m going to do more damage, so I’m taking a break and asking for advice. Worse case I pull it off and bring it to a hydraulic shop on Monday, but was hoping to had it up n going this weekend. Any insights?

 

[Joe H]

Lube the thread with ATF/acetone or whatever you have, tighten it and loosen over and over.

Not some hidden grub screw in there ?

Joe H

 

[John V]

Checked the parts manual, no grub screw in the gland nor piston. I bought the machine used back in November. Some bits and pieces were more rusted than you'd expect, so it probably saw some time in a salty environment. That's my only guess. From the parts drawing it looks like part #13 is an o-ring at the top of the gland threads, so I don't know how it would have gotten that corroded.

I'll give ATF a shot. Thanks

 

[John V]

Couple hours later, almost there… switched to the 3’ pipe wrench with 4’ cheater bar. It’s a good free workout.

 

[Joe H]

And no rust at all, no galling, nothing.

Just not holding your mouth right I guess.

Joe H

 

[John V]

I got about one more revolution after that photo and hit a brick wall. Maybe it’ll move on a Saturday.

 

[John V]

Well, I've tightened and loosen and hit the same spot multiple times. Cylinder is gonna have to come off and go to the shop. Best part is the pin holding the barrel to the blade is seized to the bushing in the cylinder. Amazing!!!!

 

[Tugger2]

Have you tried a bit of hammer work on the barrel right at the stuck threads?
Ive loosened many tight and sometimes galled threads by holding something solid like a 10lb sledge against one side and tapping the opposite side with a 4 lb. Just work on as many places as you can around the barrel and then give it another pull. It seems to work the tight spots out slowly when nothing else is working. Its better than heat on those thin wall barrells.

 

[BluewaterLa]

Rebuilt mine about two months ago.
gland and Piston nut was tight as it could be, Not easy at all once broken to get completely off the threads.
Just like yours there was no marred up threads though I suspect previous abuse pushing into things that dont move or move easily was part of the issue.
There is also a sleeve bushing inside the piston once that is off that will need to be replaced as it does not come with the kit so order that now. Pain in the rear to get out and not to easy to install.
piston was hard to get off the rod as well, spend a long time using a dead blow hammer.
Was even more tight to get it back on with the new wear sleeve bushing installed.
Never had something like this happen rebuilding cylinders though once put back together I had to install the lines to get the empty cylinder to move under pressure to line up the pins.
Figured there was going to be a failure quickly but everything operated normally and been using for two months with no issues.

 

[John V]

Rebuilt mine about two months ago.
gland and Piston nut was tight as it could be, Not easy at all once broken to get completely off the threads.
Just like yours there was no marred up threads though I suspect previous abuse pushing into things that dont move or move easily was part of the issue.
There is also a sleeve bushing inside the piston once that is off that will need to be replaced as it does not come with the kit so order that now. Pain in the rear to get out and not to easy to install.
piston was hard to get off the rod as well, spend a long time using a dead blow hammer.
Was even more tight to get it back on with the new wear sleeve bushing installed.
Never had something like this happen rebuilding cylinders though once put back together I had to install the lines to get the empty cylinder to move under pressure to line up the pins.
Figured there was going to be a failure quickly but everything operated normally and been using for two months with no issues.

Also on a Komatsu mini x blade cylinder? If so, I feel all the more happy to drop this off at the hydraulic shop today, I’m done messing with it.

 

[BluewaterLa]

Yes on my Komatsu PC35mr-2 Blade cylinder.