Dump slow to lower

Sounds like there might be a "peanut" in the pressure line to the ram... It's a flow restrictor that is often used when the full flow from the pump is to much for a particular application. By resticting the flow the movement of the ram is slowed down. It works great under pressure from pump... But SEVERLY reduces the speed of gravity return.

Another possibility is that the valve is not cycling fully to the "Return" position due to a worn linkage, or valve spool.

 

Is the valve built right into the pump???? Or is the returning fluid forced back through the pump???

I've never seen a system that doesnt have a valve somewhere... Not that it doesnt exist, just ive never seen one like that. I have however seen them where the valve is built right into the pump.

Pictures????

 

Also a peanut just looks like a normal fitting, but when you undo the fitting it only has a very small hole for the fluid to pass through... I didnt even know they existed until I discovered one while trying to figure out a similar problem.

 

This is a good picture of what I have called a peanut..

 

Single line cylinder means the pump has nothing to do with lowering. The diverter valve should put oil directly back to the tank when "lower" is selected.

Has it been slow like that since you bought it? Or did it develop recently?

Could be an issue anywhere in the return side of the circuit (including on your truck). Undersized hoses, debris caught in an orifice, excessively long hoses, too heavy (thick) oil, poppet connector to the trailer not fully seated etc.

Could possibly be too tight of cylinder packings or the cylinder binding up as well.

 

I very highly doubt the return oil goes back thru the pump. Its pretty much impossible (if you saw a gear pump opened up you'd see why). There should be a diverter valve, most likely open center, that will control pump flow to/from the trailer.

 

Even if you had a bidirectional pump (and a means to reverse it from the PTO, extremely cost prohibitive), turning it in reverse with a raised cylinder supplying the fluid you would cavitate and destroy that pump in very short order.