Slow lift at top on dump trailer

[1gr8bldr]

New member here, glad I found this place. I have a dump trailer, 6x12 that lifts fine in the beginning but gets very slow near the top. I need to understand this thing so that I can better work on it. How do you know what level the fluid should be? I added some by taking a hose loose. It did not help. If I understand it, I can figure most things out. The ram, I understand, having rebuilt most of the clyinders on my skidsteer. What I don't understand is that it has no reservior like the electric lift on my boat

 

[Tx Jim]

Most dump trailer cyl's I've seen are single acting(has 1 hose) dual stage cylinders with a reservoir. I don't understand how your system can have no reservoir. Are you sure a reservoir isn't built into the frame someplace??

 

[J_J]

Those 12 v hyd mobile hyd system, have a tank built on to the pump and he might not know that.

You have a DC motor, pump, and a tank built into one assembly

The pump would pump fluid from tank to fill the SA cyl, and in retract, fluid returns back to tank.

Do you have something like this?

Surplus Center - 12 VDC 1.3 GPM 2500 PSI SPX DA POWER PACK

 

[1gr8bldr]

Those 12 v hyd mobile hyd system, have a tank built on to the pump and he might not know that.

You have a DC motor, pump, and a tank built into one assembly

The pump would pump fluid from tank to fill the SA cyl, and in retract, fluid returns back to tank.

Do you have something like this?

Surplus Center - 12 VDC 1.3 GPM 2500 PSI SPX DA POWER PACK

Yes, it looks almost exact with the exception of the knob looking thing on the top far right

 

[1gr8bldr]

Yes, it looks almost exact with the exception of the knob looking thing on the top far right

That knob looking thing, that is actually a breather is it not? I have not seen a breather on mine

 

[J_J]

Then the long black part is the tank.

With the cyl retracted, fill the tank about 3/4 full, or there might be dipstick under the fill cap.

 

[1gr8bldr]

I have replaced all the shackles, bolts, bushings, one brake unit, adjusted the brakes, tightened the axles by the U nuts, raised the side height yesterday. Today I cut off the jack and welded a brace to remount my jack so that it allowed me a place to mount my spare. As soon as I finish fabricating a tire mount, I will get serious about fixing that lift. It held for hours unloaded in the raised position.

 

[1gr8bldr]

Then the long black part is the tank.

With the cyl retracted, fill the tank about 3/4 full, or there might be dipstick under the fill cap.

When it is retracted, the dump bed is in the way???? Will I have to pull the pins and jack up the bed?

 

[J_J]

Yes, and be safe.

 

[ptgdigger]

If you don't have a breather and the pump was designed with one that could be the problem, the pump could be creating vacuum in the reservoir and can't correctly pull fluid, the reservoir must have a way to get some air in for the fluid the pump has displaced.


Unless it is "power down" most dump beds use a single acting cylinder that is different than you are familiar with on the skid steer (double acting) , with a single acting cylinder the reservoir will be almost empty when the bed is up , this is NORMAL, all the fluid is in the cylinder , when the bed comes down it will all be forced back to the reservoir.


You can add oil with the bed powered up (you should use the safety prop) , just have to be a little more careful not to overfill. Find the fill cap on your reservoir and verify that it is very low, add about 4~6oz of oil, test ,repeat if necessary, don't put in any more oil than it takes to get the cylinder smoothly to the top. Be aware that if you overfill when you drop the bed it will spit out any excess and make a mess.


Ray