HEY THANKS GUYS I PULLED THE CLYINDERS TODAY AND FOUND SOME ONE HAD BEEN IN THERE BEFORE ME AND LEFT OUT ONE PACKING ON BOTH MAIN CYLINDERS AND FREE LIFT CYLINDER PACKING FELL APART BUT THE HR METER SAYS 743 AND IT IS WORKING MAKES YOU WONDER HOW MANY 1000 S REALY
pull the freelift cylinder ram out and check the safety valve
seen this happen on other trucks where the valve would come loose and get destroyed by the ram and cause all sorts of issues exactly like this.
If your hyd pump failed and you had debris in the hyd system, a good flushing and filter/strainer change is the first step.
I would then install a gate valve between the hyd CV and the mast, raise the mast up 24" and close the gate valve. If the forks continue to drift down, you have an issue in the mast lift cylinders or valves.
If the forks don't drift, but they drift once you open the gate valve, check your hyd CV, (poppets sticking, etc).
Looks like you have a problem with seals inside the lifting cylinders.
operator detection the forks contuine to drop after you let the handle to center
Hello Old Guy ;)
Sorry but I don't understand your problem as you describe, I believe that you changed the hydraulic pump and filters after you had no lift power and dumping hydraulic oil into the engine. Now the problem is that the forks are dropping fast when you lower them? What does OPD mean? What kind of mast is mounted?
There must be a down safety mounted inside the lifting cylinder.
Regards
Marcb