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Lost lift ability

john noteloh

New Member
Joined
Mar 25, 2024
Messages
1
Location
Iowa U.S.A.
Occupation
retired mechanic
Afriend loaned out his s40xl-mil forklift and they ran it out of hydraulic oil and now after refilling it it moves and drives but has no lift UNLESS its moving and then it jerks instead of moving smoothly. It sounds like air in the system to me so how do we get it out. Non computered antique.
 

Roadoil

Well-Known Member
Joined
Sep 6, 2022
Messages
166
Location
Vegas
I bought a non working Lull 844C because the owner ran it too low hydraulic which can cause all kinds of problems. Destroyed the plastic seals in main pump then the parts jammed up relief valves. Required new pump and lots of tracing valves.

These systems are self bleeding they work build pressure or don't.
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,054
Location
Alberta, Canada
Occupation
HD Mechanic
if the hydraulic filter is on the suction side of the pump, and it mounted above the level of the pump and the hyd. tank, it can be a pain when they lose their prime. Usually this happened after replacing the hydraulic filter after a service, but running out of fluid might have the same affect.

Check your forklift, if the hydraulic filter is mounted higher than the pump, find a way to fill the filter.
Hope that works for you.
 
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