bobcat 743 hyd lift pump

[DMorphew]

I have 743 bobcat, when raising the lift arms the pump squeals unless I increase the rpms, the more weight the more rpms required to lift. I had the valve body rebuilt, prior it wouldn't lift anything. Does it need a new hyd lift pump?

 

[laurencen]

is it the pump or the relief valve? have you tested the hydraulic pressure

 

[DMorphew]

Good question, I'm not sure at this point. I tired to find pictures on location of relief valve, couldn't find any. Would you by chance have one?

 

[laurencen]

if I recall the relief valve is on the block for the arms tilt and auxiliary, open the machine and on the right side about level with the rear of motor there should be a valve block, if you take a pressure gauge, add a bobcat connector and plug it into the auxiliary port, rev motor and operate the auxiliary lever, the pressure it reaches will be the relief pressure