Blowing hydraulic hose solution

[john p]

Still not resolved, blew hose again today and the hydraulic oil was proper hot, no problem on stabiliser setting but as soon as you turn it to boom setting you can hear the engine labouring. Some of the levers are really really stiff, could that be part of the problem? Cheers

[monkeybusiness]

I bought an ex military Rotzler hydraulic winch to run off my tractor’s hydraulics (180 bar). It wouldn’t pull the skin off a rice pudding - when I finally got the specs from Rotzler it needed 300 bar (excavator pressure). New pump and it runs great - I wouldn’t be surprised if your military DAF pump is delivering too much pressure for the MEWP though.

[john p]

Yeah, I was thinking along the same lines, might try it on a hydraulic power pack and see what happens

[Stubby]

1 hour ago, john p said:

Still not resolved, blew hose again today and the hydraulic oil was proper hot, no problem on stabiliser setting but as soon as you turn it to boom setting you can hear the engine labouring. Some of the levers are really really stiff, could that be part of the problem? Cheers

Sounds like the pipe work and valve internal diameters are too small when you switch to this circuit . 

[john p]

Yeah, stabilisers run on bigger pipe work so would make sense

[woody paul]

34 minutes ago, john p said:

Yeah, stabilisers run on bigger pipe work so would make sense

Is there a restriction valve fitted in valve block that works boom.

Or a pipe fitted back to front with fail safe fitted.

Edited September 11, 2018 by woody paul

[john p]

Is there a restriction valve fitted in valve block that works boom.
Or a pipe fitted back to front with fail safe fitted.

Going to get hold of manual with hydraulic circuit in and have a look

[woody paul]

6 minutes ago, john p said:

Going to get hold of manual with hydraulic circuit in and have a look

Could be a after manufacturer balls up. 

[aspenarb]

It would seem that the truck is pumping way to much fluid John. The mewp will have a manufacturers recommended flow rate and pressure, I would check this against the tag on your PTO pump. If the pump is run off the transfer box run it in a different gear on the gearbox, if its a gearbox driven pump you are stuffed and will have to find another pump.

 

Bob

[agrimog]

it is pressure. not flow that bursts pipes, and generally. the smaller the hose, the higher the pressure it will take, if the system was built for 200bar operation and 3/4 2 wire hoses, running 300bar will pop them, if you need the higher flow and pressure for a winch, i sugest you run this as a seperate system from the mewp circuits,  high and low pressure circuits on hydraulics require some pretty fancy( read expensive) valving and arent easy to retrofit