WEAK THREE POINT LIFT

[Anonymous-0]

I have a 1955 Ford 860 tractor. I have rebuilt the hydraulic pump and replaced the o rings and gaskets under the three point lift cover. I have also replaced the lift piston o ring and pressure safety valve. Set to 2000 psi. When using the lift today, the three point could not lift more than 600 lbs. Otherwise the lift works great. I installed a high pressure gauge in a test port on the right side under the right side foot bracket. It is a 3/8 plug. When the lift is not operating the gauge reads zero, but when lifting it reads about 400 lbs with a 200 lb weight on the draw bar and 750 lbs with a 400 lb weight on the draw bar. I tried to pick up a 800 lbs impliment today and the gauge read 1200 lbs and the lift could not pick up the load.
Should this three point pick up more weight ?
Also should the pump give me more pressure ?
I see no leak coming from the pison area.Has any one had this problem. Could it be a pump problem.
Any help or ideas wood be greatly appreciated.
Rob

 

[Larry NCKS]

Sounds like your pump is not putting out enough pressure. It should be able to "squeal" that 2000 psi relief valve.

 

[RickB]

I think you are confusing the function of the safety valve with that of the system relief valve. Safety valve protects the lift cylinder and external lift components, the relief valve establishes the maximum system operating pressure. Have you checked the relief valve?

 

[Richard_Weaver]

Rob,
did you make sure the valve body is sealed tightly against the top plate. I have a 64 2000 and it was leaking around the mounting plate....hence no pressure

 

[Anonymous-0]

Thanks to all the responses. All were very helpfull. I checked system pressure and the pump was weak. It only gave me about 1100 lbs. I replaced the hydraulic pump and all is well now.
Thanks again to all.
Rob