JD 650 Relief Valve

[PoodlePimp]

When I lift a heavy load with my FEL and the hydraulic relief valve begins to bypass it squeals. It used to be silent about a year ago. Has anybody else experienced anything like this? Would it be dirt or possibly a metal shaving caught up in the ball and seat assembly on the relief valve? Can it be pulled apart and cleaned by pulling the plug on top? My operational manual says it should be disassembled and cleaned yearly, but it looks like it's never been touched.
Also, my rockshaft rate of drop vavle is impossible to turn without sticking some big pliars on it (fortunately I don't turn it much) Is there a procedure to get this lossened up? I sprayed it with some LPS-2 and that helped just a little. TJ

 

[OkieG]

When the swing function on my #8 backhoe goes into bypass, there is a squeal. It has made noise from day one. All the other functions are quiet when they go into bypass. I believe there is just one relief valve for all the BH functions, so maybe the squeal is not in the valve. I don't know if something is wrong with that or not. Since your relief valve used to be quiet, your local JD service guys might be a place to start to find an answer.
I wonder why the relief valve on your 650 needs to be serviced every year?? I don't remember reading any such advice in any of the manuals for my 855. Shouldn't the hydraulic fluid filter pick up anything that could foul the valve?

OkieG

 

[PoodlePimp]

I thought I read that in my 67 loader manual, but looking this afternoon I couldn't find it. It does give the disassembly and cleaning instructions though. I must have gotten my wires crossed with one of the other systems. My loader use to be silent until I took it in and had the clutch repaired. They split the tractor, and ever since it sqeals in the bypass mode, only while lifting the loader, not while tilting the bucket. My thought was that maybe something is caught in the relief valve making the fluid squeal. I was concerned because the dealer did not use hyguard, so I changed the transmission fluid and cleaned the wire mesh screen but that didn't help the situation. It has good lift capability, the pump is not weak. The squeal sure is agravating when you use the loader a lot. any idea's? /forums/images/graemlins/confused.gif