how to bleed the hydr. clyinder on a dump

Automatic bleeders, thats what all the dumps I pulled had.

 

Dump cylinders always allow air to enter them. When you let the body down always put the control lever back in the neutral position. Most dump truck drivers leave the control in the down position this allows fluid to return to the tank if the packing rings on the cylinder leak slightly. The weight of the fluid wants to return to the lowest point in the system(the tank) if the packing rings allow air past them the fluid gravity feeds into the tank and the air is at the highest point, the cylinder. To bleed a dump body correctly whether it's a dump truck or dump trailer is to raise the body fully, then lower it to within 6" of lowered. Hold the body at this position while bleeding the air off at the top of the cylinder. This way you've raised the cylinder fully and allowed the air to get trapped in the last stage of the cylinder. When you lower it to 6" from the frame rail, you still have the weight of the body being supported by the cylinder and creating pressure to push the air to the top. You can then get into the body and to the top of the cylinder safely to bleed it. If you don't bleed all the air before the body comes to rest..........repeat the whole process until you no air coming from the bleeder.

The cylinder may need the packing rings tightened, but take the truck to a hydraulic shop to do this properly. If you try to do it yourself you can have problems in how the cylinder stages raises and lowers...........this can be very dangerous with the dump body dropping a complete stage of the cylinder while trying to raise it under a heavy load or the dump body not coming down properly after dumping a load

 

I hate the dang gone things..........they always seem to allow oil past them to make a mess of the truck and trailer

 

air in dump cylinder makes PTO pump work with zzzzz sound, but it is normal.
Dupm truck system is self bleeding system, like PS system, and do not use autobleeders, truck looks greazy! the only good thing with automatic bleeders - oil on frame inhibits rust)))

 

Wasn't my trailer so it wasn't my choice. It never failed anyway, I'd always have a cylinder that leaked a little so the bleeder was of no worry.

But it did work.

 

Had one drop one scope and slam the deck while I was standing there taking a wiz once....

Good thing I already had it out of my pants!

 

Dude you drive a Freightliner! Everyone expects it to have oil all over it, under it, all over the driver (especially his hair).