3-Point Hitch Mahindra 4530 blowing out pressure relief valve

[wrighttim34]

I have a Mahindra 4530 4wd that after 13 years has started blowing out hydraulic pressure relief valve. As long as tractor is just idling things are fine. As soon as three point or grapple is engaged the valve blows out. Any ideas.

 

[K5lwq]

When you say blows out, is it bypassing or oil is coming out? Can you put a pressure gauge on the line feeding the loader valve? And lastly, is it the main relief or the one on the loader?

 

[ptsg]

If it's indeed blowing hydraulic fluid out, you can take the whole cartridge off to replace a couple O-rings and a backup ring in there.

Just be careful to not mess with the relief adjustment.

 

[wrighttim34]

When you say blows out, is it bypassing or oil is coming out? Can you put a pressure gauge on the line feeding the loader valve? And lastly, is it the main relief or the one on the loader?

It痴 the main valve in front of the tank. The whole valve blows out-spool conpensator,spring,plug assembly and snap ring with hydraulic fluid pouring out.

 

[LouNY]

Itç—´ the main valve in front of the tank. The whole valve blows out-spool conpensator,spring,plug assembly and snap ring with hydraulic fluid pouring out.

If the valve is physically being blown out you definitly have a problem, is the port to go back into the tank plugged?
You are saying tank, is that the tractor reservoir?
Most of the tractors that I have worked on the pressure relief is either in the loader valve bank,
or at the 3 point valve area.

 

[wrighttim34]

If the valve is physically being blown out you definitly have a problem, is the port to go back into the tank plugged?
You are saying tank, is that the tractor reservoir?
Most of the tractors that I have worked on the pressure relief is either in the loader valve bank,
or at the 3 point valve

Tractor reservoir. The valve is located under the seat in front of the reservoir where the 3 pt valve is.

 

[K5lwq]

That is a strange one. Pictures would help. I think you have to have five post to post a picture. I would assume it is threaded. Are threads stripped? A new relief valve sounds in order but still need to verify pressure.

Below is a picture of an old pressure relief valve I had laying around. Does it look similar?

 

[wrighttim34]

That is a strange one. Pictures would help. I think you have to have five post to post a picture. I would assume it is threaded. Are threads stripped? A new relief valve sounds in order but still need to verify pressure.

Below is a picture of an old pressure relief valve I had laying around. Does it look similar?

View attachment 644966

Not threaded. Only thing holding it in is an interior snap ring set in groove of valve port.

 

[K5lwq]

As Lou stated, something is definitely wrong. But I guess you don't need us to tell you that.

I tried to find a picture or parts diagram with no luck. The fact that it is physically being blown out would normally point to it not being properly seated before the snap ring is installed. It is hard to imagine that enough pressure is being built to blow it out otherwise.

If a pressure gauge was put on the line feeding the loader, it would be interesting to see what flow pressure is reading without moving any valves. If it is high, like 2000psi or so it would indicate a blockage somewhere.

If it is around 200 PSI or so, and you try to move the loader with no weight and pressure stays around 1000psi and it blows, then you would know it has to be something with the relief valve.

The relief valve should be set somewhere around 2500psi and should not blow out if that was reached constantly. Oil would get hot, but the valve should remain intact.

If you get a chance, post pictures and keep us updated on your findings as this with be interesting to say the least.