Posted by Paul (in NY) [12.64.114.66] on Thursday, September 19, 2013 at 15:44:51 :
I have a Watco 303 HC, 3 ton floor jack. The previous owner got rid of it because it was quickly creeping down and hardly pump up. I bought a Watco 303 HC rebuild kit from Black Hawk Jacks in Tn.
The release needle valve had a wear mark which I cleaned up with crocus cloth.
The reason she was creeping down, was blow by the deteriorated seal on the piston. I replaced that seal and also the seal on the pump shaft, as I did all other replaceable o rings and balls. Both cylinder bores were perfect
She no longer creeps down and will jack to full 26" height. But now the problem.
The floor jack will only lift about 90 pounds. Pump the handle as much as you want and it will barely lift a bag of cement. Trying to jack the front side of my W300, it would not lift it at all.
Does anyone have a diagram of the fluid flow inside the jack so I can trouble shoot her more.
On the main pump/lift cylinder are 3 ports with valving. The center port is easy to figure, its a pressure relief so you cant lift above Jack Design. On each side of the relief port are ports with a spring and ball. I need to know what these 2 valves are for.
This is a old heavy duty jack. I cant begin to lift her on the work bench. For sure not Harbor Freight Quality LOL.
Paul
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