squealing pressure relief valve

[tigershark57]

Hi I'm the new kid on the block and I need some help on this hydraulic question?
I have a C174 hinomoto tractor with a squealing pressure relief valve. This happens when the front end loader is raised or lowered without any weight. I have checked out the pressure relief valve, the hydraulic lines to and from the control valve and everthing appears to be good. I've attached a pressure guage to the control valve and the pressure reads 1200 psi. I've also tried lowering the pressure to see if this would help, but no luck. Does any one have any suggestions as to what to try next? Any help would be greatly appreciated!!!
Thanks

 

[3RRL]

What is the suggested psi rating for your tractor? Is it higher than 1200psi? Try turning the pressure relief up to what the manual says, if it's higher than 1200psi. If it still does it, remove the valve and check for a worn spring or any worn gaskets or "O"rings. If that doesn't work replace it.

 

[jinman]

Hi I'm the new kid on the block and I need some help on this hydraulic question?
I have a C174 hinomoto tractor with a squealing pressure relief valve. This happens when the front end loader is raised or lowered without any weight.

I don't think your problem is the pressure relief valve. If the pressure relief valve was squealing, your loader would quit working because the fluid is being bypassed. You say that you are hearing this with no weight (load).

It sounds to me like there is a loader valve causing vibration that sounds like squealing. Often, rigid hydraulic lines will vibrate together or in clamps without the proper rubber grommets. It also could just be a noisy joystick valve.

Also, if you have dry pivot points that need grease, they will sometimes squeal and squawk really loudly.