this may well be (sounds to me) what I call the "velocity fuse" in the lift cylinder hydraulic circuit.
Forklifts (when new and repaired as designed) have a device that is designed as a 1 time use/non-reset-able hydraulic fuse, that is designed to prevent a 'guillotine' effect of the carriage falling like greased lightening should the primary lift feed hydraulic hose break between the mast and the valve. it doesn't prevent oil leaking or the carriage coming down **** quick, just not as quick as without that fuse. when 'blown' the fuse does not prevent lifting, it just limits flow when lowering, you may be seeing the effect of that limiting factor. In thins truck, I think they call it a lowering control valve and it looks like a fitting into the tee that has the hose from the control valve, (and that is the hose the valve attaches to) and hoses that go to the lift cylinders, but this lift cylinders also look to have a fitting-spring and washer setup in the bottom of the lift cylinders that may also be part of your problem and worth checking by pulling the fitting out of the bottom of the lift cylinders to see if it may be malfunctioning..
I am soooo very tempted to say this, but I would NEVER EVER say this...
the best way to know, and maybe the only way to ever get this unit to run right again would be to fly -me- to your neighbourhood to look at it, for a week, maybe sometime in January...
But I would never say that... [and besides, Stam would need it more than me... what with him living in the 'great white north' and all].
;-)
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