Mahindra 2538 6' bounces

[dwalk19]

It ended up being a bad relief valve for the 3 point hitch, covered under warranty

 

[SPYDERLK]

Thanks for closing the loop.

Good news. I had thought that relief valves only acted during lift - not hold. My Kubots are that way I know. If my 7520 acts up Ill keep it in mind.​

 

[Dave M7040]

Thanks for closing the loop.

Good news. I had thought that relief valves only acted during lift - not hold. My Kubots are that way I know. If my 7520 acts up Ill keep it in mind.​

You need to realize there are two relief style valves on the 3 pt hitch.

The normal one which limits how much weight it will lift.

The second one, usually called a safety valve, is in the cylinder circuit when you are traveling with a heavy implement on the 3 pt.
The safety valve's purpose is to protect the 3 pt against the loads caused by bouncing implements.

The safety valve has to be removed and tested on a fuel injection machine as its release pressure is much higher than the tractor's hydraulic system can develop.

This schematic is from a Kubota but other brands are similar.

Dave M7040

 

[SPYDERLK]

You need to realize there are two relief style valves on the 3 pt hitch.

The normal one which limits how much weight it will lift.

The second one, usually called a safety valve, is in the cylinder circuit when you are traveling with a heavy implement on the 3 pt.
The safety valve's purpose is to protect the 3 pt against the loads caused by bouncing implements.

The safety valve has to be removed and tested on a fuel injection machine as its release pressure is much higher than the tractor's hydraulic system can develop.

This schematic is from a Kubota but other brands are similar.

Dave M7040

Ah! That makes good sense. I think the L3450, an older Kub, does it with a rupture disc.

The rocker arm on mines rocker shaft broke and during fix I saw what I thought was a rupture disc setup that had failed to protect it.​

 

[Dave M7040]

Ah! That makes good sense. I think the L3450, an older Kub, does it with a rupture disc.

The rocker arm on mines rocker shaft broke and during fix I saw what I thought was a rupture disc setup that had failed to protect it.​

I do not know for certain but the use of a rupture disk in a farm tractor would be most unusual. The manufacturer is designing to protect the equipment not to put it out of service which a rupture disk would do. Further, with a rupture disk the manufacturer risks someone using something else to get the machine back working.

I am not saying you are not correct just that I have not seen it done and I can see lots of reasons why it would not be done.

If an amateur was messing around trying to increase the lifting power of the 3 pt and inadvertently changed the safety valve then real mechanical failures would happen.

Dave M7040