Remote cylinder problem

[Jim Knapp]

I recently purchased a JD 3 1/2"X 8" remote cylinder from a local salvage. After working 2 days with my 4020 pulling a crustbuster springtooth, two of the 3- 3/8 X 1 bolts popped off letting the "guide" slip foreward. I got the broken ends out and replaced the bolts and promtly popped all three bolts again. Serviceman checked the tractor hydraulic pressure-2250 lbs. so thats probably not the problem.

I disassembled The cylinder, everything looks OK. But looking at the exploded view on JD Parts, it appears that the cup of the piston is toward the upper (rod) end of the cylinder. When I took my cylinder apart, the cup was toward the lower end, over the nut. I haven't went back to the shop since looking at the exploded view, but it looks like with the piston installed with the cup down, the part of the piston near the rod would strike the "guide" before striking the end of the bore in the cylinder. This would put all strain to stop the piston and rod on the three 3/8 bolts. Has my cylinder been assembled wrong at some point or can someone give the reason that the cylinder blew out?

Thanks for any advice

Jim

 

[JBarbee77]

Seems to Me like your on the right track. (I know you havn't been back to the shop.) You have to look at the piston and see if there is any damage. If there is you know that is it. Seems to reason, that it would leave some kind of mark.

Good luck

Jason

 

[WTW]

Jim,
That is exactly what was wrong. The piston was installed backwards. Been there and have seen this same thing happen before. Cup on piston goes toward the rod end and straddles the rod guide that protrude in cylinder barrel. You got it figured out. DW

 

[Jim Knapp]

I think turning the piston over fixed it. No apparent damage. We will see when it's back in the field. Thanks for the advice.

Jim