forklift help needed

[CaptTrev]

Hey guys,

I need a little forklift help here. . . (this is for a forklift we have at work, but fixing it fell into MY lap)

The forklift in question is a 1981 TCM FG25N5. Its a small to medium sized gas engine lift (4cyl). pnematic tires, 2 FWD and 2 REV speeds. up/down and trim fwd and trim back.

the problem we've been having with it is that when you raise the forks up they immediately begin to slowly work their way back down. this only occurrs in the up/down, not the trim.

the problem seems to have developed since the lift has been sitting outside all winter in the VERY cold. the problem doesnt seem to go away when it warms up.

Im guessing that the hydraullic switch isnt working well and is allowing fluid to blow by?

Any ideas on how to fix/remedy the situation?

any/all ideas much appreciated.

thanks!

Trevor

 

[Loose_Nuts_Enterprises]

There is a loss of pressure somewhere. would think that if it's not leaking externally (puddle), the seals in the valve must be worn and letting fluid return to the reservoir because of the weight of the forks (and Gravity). Or you could call someone qualified to work on these. Hydraulics are not rocket science, but you may not want to suffer the liability if something fails after you've been working on it. Just MHO.


Dan

 

[CaptTrev]

you may not want to suffer the liability if something fails after you've been working on it. Just MHO.


Dan

hmmm...thats an excellent point. . . . . . . .

 

[Matthew Currie]

There is a loss of pressure somewhere. would think that if it's not leaking externally (puddle), the seals in the valve must be worn and letting fluid return to the reservoir because of the weight of the forks (and Gravity). Or you could call someone qualified to work on these. Hydraulics are not rocket science, but you may not want to suffer the liability if something fails after you've been working on it. Just MHO.


Dan

I've dealt some with old tractors and backhoes, and it could be either a bad valve or a bad piston if the piston is double-acting (i.e. lowers under power rather than gravity). A single acting piston will leak at the seal if fluid gets past it, but a double may not.

Anyway, I agree that with the potential liability of a forklift dropping something on someone, it's best to call someone in on it.

 

[Moto]

Sounds like you have either a bad piston or control valve. It is a forklift so more than likely the forks lower thanks to gravity. If it is leaking at the cylinder, it is really easy to repack the cylinder, but if it is a valve, it will more than likely have to be rebuilt or replaced. It is up to you guys at your work tho, if you do a crappy job repacking the cylinder or replacing the valve or whatever and it falls, the liability is on you, but any person with basic saftey knowlege knows not to stand under a hoisted load on a forklift, or anything hydraulic for that matter, that is why we use jack stands with our Jacks. But not everyone has common sense.