pto hydraulic pump problems

[jasonblack72]

Hi all. Got my hands on a pto hydraulic pump shes a dowty pump. 100cl. Thought it would power my splitter. Hooked it up and put the tractor in the 1000 shaft on the pto. Tried to split timber and doesnt seem to be buildind pressure. When she does after 15sec shel rev the engine on the tractor. The oil on the return is a wee bit foamy going back in to the return tank. When I toke the pipe off the tank noticed that it wasnt a solid flow of oil, more spitting it back. The pump I was told can return between 20-25 lpm so more than enough I think.

Does anybody know what the problem is?

[ewd ripper]

Hi all. Got my hands on a pto hydraulic pump shes a dowty pump. 100cl. Thought it would power my splitter. Hooked it up and put the tractor in the 1000 shaft on the pto. Tried to split timber and doesnt seem to be buildind pressure. When she does after 15sec shel rev the engine on the tractor. The oil on the return is a wee bit foamy going back in to the return tank. When I toke the pipe off the tank noticed that it wasnt a solid flow of oil, more spitting it back. The pump I was told can return between 20-25 lpm so more than enough I think.

Does anybody know what the problem is?

 

Sounds like its drawing air in on the suction side off the pump somewhere check the pipework and the connections and make sure everything airtight.also make sure the return pipe is big enough to take the flow of oil bigger the better:thumbup1:

[jasonblack72]

There is a bit of wear on the intake pipe. If I change it should it work? The return pipe is the one came with it. It was used for a rapper on a round bailer so the oil on it would have been greater im sure. Can she also be airlocked?

[treequip]

Ummmm

 

Dowty haven't made pumps for quite a while now so there is every chance that the pump is suffering from old and knackered.

 

Check first that the supply pipe from the tank is big enough, that could be causing cavitation.

[scraggs]

are you actually running it at 1000rpm ?

if so try it at 540 as that again could cause cavitation

[jasonblack72]

Yea ran on 1000 but also tried 540 and didnt make much odds. I think maybe il try a new hose on her and see if that makes any different. Also noticed on the pump theres a bleed screw on the side closest to yhe tractor. Then looking at it there was no oil in it. Should there be?

[aspenarb]

Are you sure you have the pumps pipes on the right way round?

 

Bob

[jasonblack72]

As far as I know the pipes are correct. How I think is that the intake will have to come from the bottom of the tank and the return goes to the top threw the filter. Back into the tank.On the pump the feed should go to the top and the feed coming back out to splitter at the bottom? Am I correct are badly wrong?

[openspaceman]

As far as I know the pipes are correct. How I think is that the intake will have to come from the bottom of the tank and the return goes to the top threw the filter. Back into the tank.On the pump the feed should go to the top and the feed coming back out to splitter at the bottom? Am I correct are badly wrong?

 

Pressure out port is generally smaller than the in port, direction of rotation is often marked on the pump or can be derived from the serial number. Oil should return to below the level of oil in tank to avoid entraining air. Cavitation (from things like trying to suck through a long pipe) kills these pumps quickly. As has been said Dowty stopped making them years ago so it may be goosed.

[jasonblack72]

She rotating the correct way arrow shows this.she builds up pressure but takes atlest 20 sec to do so.the ram on the splitter is very jerky as well.