Hydralic pump

RJK

Member
I'm working on a 68 Ford industrial. the 3 point will only come up if I have nothing connected to it. I checked pressure at the pump. all I can get if I rev the engine up is about 500psi. any suggestions before I tear into this pump? Ray
 
Could be the relief valve or unloader valve is stuck partially open not letting enough pressure to build. Could also be the piston o-ring is shot. Always good to mention the exact model of tractor you have and which transmission it has so we know which type of pump you're dealing with. Only the 3400 would always have the side engine mounted piston pump. Any other industrial models from 1968 could have either the side engine mounted piston pump or the gear pump mounted in the rear axle center housing depending on which transmission and PTO options it has.
 
(quoted from post at 19:57:21 04/25/20) Did you have something on the lift when you tested the pressure? Hydraulic will only develop the pressure it takes to move the load.

Good point. I assumed that his 500 psi reading was when trying to lift something that it could not lift, but it would be good to know for sure.
 
(reply to post at 03:02:57 04/26/20) No there was nothing attached I didn't realize it made a difference. I'll hook up the drag today and see what I get. I'll figure out what model and trans I've got and let you Know. Thanks, Ray
 
The serial #is C194945 the other numbers above that are 8B12B
and 350226.the 6 might be a 0.then next to each other in front
of the seat on the top edge of the differencial housing and
trans are 42A13 and 7m12B
 
Some pressure will register from the resistance of pumping fluid through the system. When lifting the pressure will rise to only where it overcomes the load and drop back when it hits the set height. I don't mean to be condescending but it sounds like you don't understand how they work.
 
350226 is most likely 35022C or 35022G, which is a model 3500 tractor with a gasoline engine, non-live PTO and if the last character is a C then it has an 8 speed transmission and if it is a G then it has a 4x4 manual reversing transmission. Is there only one reverse in the shift pattern of the main shifter, or two? Forur forward and one reverse on the main shifter with hi/low on the shorter range shifter is the 8 speed and two forward and two reverse on the main shifter with hi/low on the secondary is the 4x4 manual reverser.

8B12B is the Unit Number, which says it was made on February 12 1968 during the day shift.

C194945 is an early 1968 serial number which agrees with the Unit Number above.

It should have the 3 point pump mounted on the left side of the engine back near the flywheel. Definitely test the pressure when it is trying to lift something that it cannot lift and post that back here.
 
your right mike, I've never had a reason to get into one of these systems. My tractors never have had any major hydralic problems. This one was a "gift" from my nephew. so I guess I get an education.
 
I'm adjusting the draft on the 3500 individual. I have the cover
in the vise. The book says for the current model I should set it
at .o30.and for the previous model. .200. How do i tell which
one i have?
 
Previous model is any tractor made before April 1, 1968. Yours was made February 12, 1968, so yous is a previous model. They mad a lot of changes on 4/1/68.
 
Thanks Sean, I went ahead and adjusted it as the previous model. I'll put it back together today. Ray
 
Well Sean this is where I'm at. Adjusted everything under the cover. Pressure tested the 3point under a load, got 300psi. It will lift with no weight. Can you tell me where the relief valve is located . I want to check it before I get into the pump. Ray
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top