forklift hydraulic problem

[Brad_bb]

1975 Warner Swasey rough terrain forklift(ford based). 8000 lb lift capacity. Just bought it recently. The side shift cylinder is leaking externally. The two tilt cylinders drift down by themselves quite quickly whether under load or not(faster with load). You can return the lift carriage with the lever, but it will immediately drift down again. I want know is this a problem with the cylinders themselves or the control valve? I also recently started it and was lifting the carriage up and it stopped about a third of the way up so I suspect that the hydraulic fluid is low. It acts like it. I don't think that's the problem with the tilt cylinders though. This is my first time working on a forklift or hydraulics like this.

Is there a better forum or website that I should be posting my question on?

 

[showcrop]

I have a 1969 Yale that I used regularly up until 5 years ago. Every now and then the tilt drifts but after working the valve back and forth a few times it will hold, so I attribute this to a dirt particle in the valve. Mine leaks at the main packing and after leaking for so long it will not lift all the way so I just add oil. I fixed the supposedly rebuilt alternator on it last year, which was the most bothersome problem, so it is probably time to get on to the next one.

 

[Vern113]

I am a 30 year forklift mech. the tilt cylinders need to be repacked. If one of the tilt cylinders packing fails then the oil will transfer to the other causing the mast to drift especially with a load, and the lack of lift height is most likely caused by low oil level. Be sure to check oil with the engine off and forks on the ground.