Hydraulic Ram stopped working on plow.

mattridessleds · Jan 3, 2013

Alright here it goes... I have a kubota L2800 with rear remote that I have 2 lines that run to the front loader where I have a fisher plow that I welded to a skid steer quick attach plate. The 2 lines power the angling rams on the plow so I can angle it left and right. The other day while I was plowing on side stopped working. So I have a very limited knowledge of hydraulics. I pulled the cylinder off and replaced all the internal seals figuring it was something internal. Well needless to say that apparently wasn't the problem. The other ram works fine and I can run it off either one of the 2 lines even after switching them on the ports on the remote valve. So I don't think that it is the remote valve or an issue with the feeding lines. So I'm baffled. I can take the cylinder off put it in the vise in my work shop and get it to come out with like 120psi of air pressure so I know the seals are holding. My thought was that maybe the remote valve isn't putting out enough pressure but the other cylinder works fine even with a load against it. These are single acting cylinders so when the one cylinder is extended it pushes the other side in. Thanks!
-Matt

oldnslo · Jan 4, 2013

When yoy try to angle the blade do both hoses get pressurized when it fails to move? If yes it sounds like the QD (quick disconnect) is preventing oil from returning on the cylinder that is trying to retract. Try feathering the control to angle the blade slowly to see if it will work then. If it does it most likely is the QD preventing return flow. These occasionally have springs that weak or break in them causing this problem.

mattridessleds · Jan 5, 2013

Ok thanks Ill give it shot next time I get a chance. Sounds like it could be it.

zzvyb6 · Jan 5, 2013

Me thinks you may have the plow cylinders cross connected. If so, then pressurizing the larger piston area cylinder (no rod) wins every time. Hence it only likes to go 1 way. In one ear and out the other...

J_J · Jan 5, 2013

There are several reasons why a cyl will not move.

No fluid flow.

No fluid return port available. Relief will activate.

Bent shaft. Relief will activate.

Hoses not connected correctly, but no fluid flow answers that.

QD's not working correctly, and no fluid flow covers that.

Soundguy · Jan 5, 2013

check all qd's first.

then swap hose functions..

if a da cyl, leave one side open to air and pressurize other..

post back

mattridessleds · Jan 5, 2013

I'll play with it a little tomorrow, at work now. I am leaning towards a bad qd. I'll let you guys know. Thanks for the replies.

Soundguy · Jan 5, 2013

if they get partially unseated they can fully block flow

mattridessleds · Jan 10, 2013

It's one of the qd's. If I feather the valve the cylinder will move. Pretty sure it's one on the Remote itself. Wish I had got on here before I rebuilt the cylinder. Thanks guys appreciate the help!