I've been trying to diagnose this one for a while... Bobcat 753G
I now have a pressure valve on a tee on the retraction side of the lift boom - lowering the boom with the bucket on the ground gives me:
(With the machine cold), I get 2100 PSI at idle and 2500 PSI full throttle
(With the machine warm), I get around 1100 PSI at idle and 1500 PSI at full throttle - when the machine is warm it isn't able to lift the boom except for small jerks when I press and release the pedal
Tilt seems okay through out this process
I've tried capping off each lift cylinder extension hose and attempted to retract the lift (with the bucket down) to check for fluid bypass but there was none - I then capped off both extension hoses and tried lifting to check for load on the engine (per Willies suggestion) but the engine did not seem to bog down
Could the port relief valve be the culprit? If so, what should I be looking for when taking it apart?
Could it be the spool valve leaking? Any way to narrow it down to this?
Could it be the gear pump itself? I wouldn't think so, because the tilt is working okay, but maybe the tilt doesn't require as much power?
Any advice on what I should do next to diagnose would be greatly appreciated
I now have a pressure valve on a tee on the retraction side of the lift boom - lowering the boom with the bucket on the ground gives me:
(With the machine cold), I get 2100 PSI at idle and 2500 PSI full throttle
(With the machine warm), I get around 1100 PSI at idle and 1500 PSI at full throttle - when the machine is warm it isn't able to lift the boom except for small jerks when I press and release the pedal
Tilt seems okay through out this process
I've tried capping off each lift cylinder extension hose and attempted to retract the lift (with the bucket down) to check for fluid bypass but there was none - I then capped off both extension hoses and tried lifting to check for load on the engine (per Willies suggestion) but the engine did not seem to bog down
Could the port relief valve be the culprit? If so, what should I be looking for when taking it apart?
Could it be the spool valve leaking? Any way to narrow it down to this?
Could it be the gear pump itself? I wouldn't think so, because the tilt is working okay, but maybe the tilt doesn't require as much power?
Any advice on what I should do next to diagnose would be greatly appreciated
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