checking hydraulic pressure on the hydraulic pump on a fo...

ejensen

Well-known Member
Our tractor, 1953 ford jubilee, has the style hydraulic pump which is run by a pump on side of the engine. Where is the port to connect a hydraulic pressure gauge?
 
(quoted from post at 12:39:23 07/25/18) Our tractor, 1953 ford jubilee, has the style hydraulic pump which is run by a pump on side of the engine. Where is the port to connect a hydraulic pressure gauge?
epends on the type of pump, piston or vane. Piston has hex plug on top front, but not vane type. Other places are right side of hyd compartment near brake petals (be sure what you know what you are removing or trouble may occur) and then there is the accessory plate under the seat. None of these will yield full pressure unless you chain lift arms down and apply lift command.
 
There are two different engine mounted pumps that could be on your tractor. The original was a vane pump and had a square body, and the later style which have been used to replace the original vane pumps is a piston pump which has a round body. The vane pump doesn't have a test port, but the piston pump does.

For one with the vane pump the only place to test the pressure is the hole with the large bolt in it in the blocking plate, which is the 3x5 plate that is on the top cover, which you can see by sitting on the seat and looking down between your knees.

On one with a piston pump you can use that same test port on the blocking plate or you can use the port on the pump body.

In any case, to test the pressure you will need to chain the lift arms down and raise the control handle, basically attempting to raise the arms that are chained in place. At that point you will be measuring the pressure that the relief valve opens at, or less if the pump is weaker than the relief valve.

If the lift is not working such that the arms don't try to lift at all, then you probably won't be able to get a pressure reading because there is probably some issue under the top cover that is allowing the fluid to return to the sump without being restricted by attempting to lift the arms, and pressure is a measure of resistance to the flow, so if there is no resistance there is no pressure.
 
(quoted from post at 13:26:47 07/25/18) Jmor
Thank you
ressure test point marked.
hMZXq8a.jpg
 
My jubilee has round pump which I installed a pressure gauge at the bleeder plug. To my surprise if you are not lifting anything there is zero pressure. The pressure increases when you lift something.
 
(quoted from post at 17:34:57 07/25/18) My jubilee has round pump which I installed a pressure gauge at the bleeder plug. To my surprise if you are not lifting anything there is zero pressure. The pressure increases when you lift something.

Exactly.

Pressure = flow + restriction

If there is no restriction (something for the flow to push against) then there is no pressure. Chaining the lift arms down will prevent the arms from being able to lift, thereby providing the most restriction possible, thereby obtaining the highest pressure possible.
 

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