Dump Truck Hydraulic problem stuck, wont come back down.

[Sir Donald]

I have a problem with hydraulic cylinder. Truck is new to me. it worked fine if i didn't go all the way up. Telescopic style. Top stage wont retract. i have tried draining the fuild and it still didn't come down.

First off the dump bed is about a foot from touching the safety lock so i am being careful

next i drained all fluids from where my finger is pointed. Guessing this was another location for another spool

here is a picture of the pump area. what is my next move?

 

[Sir Donald]

I have disconnected the hose and it is still up

 

[Delmer]

First put the hydraulics back together. The other sections came down so it's not a hydraulic problem.

Did you try raising it and letting it down a few times? Make sure the top and bottom pins, and hinge pins are greased and not binding. Is it off level? try rocking the bed side to side, or hit the gland area of the cylinder front to back with a 2x4 with the valve held open, from a safe distance of course.

 

[digger242j]

I had one once, that was a 1 ton dump with an electric hoist. It was mainly a plow and salt truck. Beat my brains out trying to figure out why it wouldn't come down. It turns out that the hinges were so rusty that the hoist could push it up, but when empty, the bed didn't weigh enough for it to come back down. I got it down by pushing it down with a backhoe. Not saying that's the problem here, but it's not impossible.

 

[Sir Donald]

Update. We have hooked up all hoses, raised the bed unpined the cylinder, greased, smacked with hammer big one, released vent from top so fuild would release down

 

[DMiller]

You figure out the 'Why' yet, burr, gouge, rolled piston packing??

 

[Sir Donald]

No bur, no gouge, no other outlining whys visible from the outter view. Not sure what a rolled pistion packing is. Could be that. I'm taking it as is to a tool shop to be rebuilt tomorrow. Will update soon.

 

[td25c]

Sounds like the cylinder is " jacked up " . Bent tube , something like that .

Ran into this before .
http://www.heavytruckforums.com/showthread.php?263-Some-Holmes-750-action&p=1606&viewfull=1#post1606

Good move on getting it rebuilt .

If my memory is correct the dump trailer cylinder was around $ 2,500 rebuilt .