How do I hook up my hydraulic pressure gauge to test relief valve?

[lens12]

When the hitch reaches the end of its travel, the relief valve is activated to prevent deadheading the pump.

 

[RickB]

When the hitch reaches the end of its travel, the relief valve is activated to prevent deadheading the pump.

If the relief valve is activated at the end of the hitch travel, the pump IS deadheaded. That means pump output is forced to build to relief pressure before finding a path back to tank. Not normal or healthy for the pump. A properly adjusted hitch valve allows the oil to return to tank at low pressure when the hitch reaches the upper limit, or for that matter, any preselected position. Some tractors have a "test" position at the top of the quadrant that will deadhead the pump output, perhaps the subject tractor has this characteristic.

 

[dieselfuelonly]

I know that if I try to continue lifting my 3pt hitch after it reaches the end of its travel the relief valve will squeal, so I'm thinking that will work.

 

[FL_Jerry]

I'm thinking something is out of adjustment then. There is feed back linkage so when the arms get to the desired height, the lever gets pushed away from the 3pt valve input pin. There are some old posts by Soundguy saying they used to chain the 3pt arms down.....


Jerry

 

[rhett]

dieselfuelonly, if you do adjust the pressure relief, please do it to specs. about six weeks ago this post was started Broken rear end...what are my options? . true the auger grabbed and drug it down, but trying to lift a gazzillion pounds wouldn't be to healthy either.

 

[lens12]

If the relief valve is activated at the end of the hitch travel, the pump IS deadheaded. That means pump output is forced to build to relief pressure before finding a path back to tank.

The whole point is that the original poster wanted to test the relief valve pressure. My response was a way to do it.

 

[RickB]

If the relief valve is activated at the end of the hitch travel, the pump IS deadheaded. That means pump output is forced to build to relief pressure before finding a path back to tank.

The whole point is that the original poster wanted to test the relief valve pressure. My response was a way to do it.

My point is that you are incorrect. If the relief valve is activated as a matter of course each time the hitch reaches the top of its travel, the hitch valve or follow up linkage is out of whack, and the pump will be junk in a short time.

 

[lens12]

I agree that "If the relief valve is activated as a matter of course each time the hitch reaches the top of its travel, the hitch valve or follow up linkage is out of whack" I disagree that "the pump will be junk in a short time." since the relief pressure of a YM1401 is 1138 psi. These pumps are built for a lot higher pressure than 1138 psi. The YM1401 3 point control valve must be held in position to operate the 3 point. It is not a position valve like most models. When it is held in at the top of the 3 point travel the relief valve will be activated & the pressure can be checked on a gauge. It is still a way to check the relief valve. If the relief valve is activated at the end of the hitch travel, the pump IS not deadheaded. I still think my point is correct.

 

[dfkrug]

If the relief valve is activated as a matter of course each time the hitch reaches the top of its travel, the hitch valve or follow up linkage is out of whack, and the pump will be junk in a short time.

Most new CUTs come with adjustable limiters for the 3-pt lift control. If
not used, many (most?) will send the hyd system into relief at the highest
lever position. My 1st three Kubotas were beat up used ex-rentals and they
had no limiters. Often the lever was pushed to the top and the relief
valve could be heard (2000 psi, measured). The engine strained, too, but
this will not hurt anything if you don't run it for minutes and over-heat the
oil. Numerous new tractor owners have experienced a "sick" tractor, only
to find the cause was the 3-pt position lever was in the relief position.