Noisey hydraulic valve

[stevewatr]

Hi, been working on my Oliver 770, came across an issue, thought I'd post symptoms, and get some thoughts.

tractor is fitted with a Ware loader/backhoe.

I changed the fluid in the resovoir, and the filter (return line type).

Fluid was milky, and filter was really nasty.

With fluid topped off, symptoms are as follows:

No unsual noise when running, and all spool valves in neutral.

When raising loader, a terrible noise comes from the loader valve, sort of a low pitched screech, and the loader seems slow to me. I say seems slow because this machine is new to me.

Lowering loader makes no noise, and I have enough down pressure to raise front end off the ground.

Backhoe swing cylinders, and boom work fine, and stabilizers can raise rear of tractor quickly, no strange noises, so I figure pump pressure is ok.

dipper stick cylinder is very slow, but no strange noise, so I think that's just a worn piston seal. Backhoe bucket cylinder has a bad leak, so I am not testing that for now.

Based on the above, anybody have any thoughts?

Thanks,
Steve.

 

[oldnslo]

Do you have quick disconnects on the hoses to lift / lower lines on the loader? If yes try raising the loader very slowly by feathering the valve. If it quiet try going a little faster and see if the noise starts. If the noise starts one of the quick disconnects for your loader is velocity shifting from the oil flow. It may just need to uncoupled and re-coupled to work properly or they may need to be replaced.

 

[stevewatr]

Do you have quick disconnects on the hoses to lift / lower lines on the loader? If yes try raising the loader very slowly by feathering the valve. If it quiet try going a little faster and see if the noise starts. If the noise starts one of the quick disconnects for your loader is velocity shifting from the oil flow. It may just need to uncoupled and re-coupled to work properly or they may need to be replaced.

Hello, and Happy Easter. No quick disconnects. this loader is kind of made to stay with the tractor all the time. The noise is definitely coming from the valve body, and since the loader also seems to be too slow, I think the noise is from a malfunctioning relief valve. I'm going to pull the valve and inspect it. Thanks for the reply, I'll file that in my skull "database" for future reference.

Steve.

 

[stevewatr]

In case anybody is wondering, I fixed the issue, it was a bad hose, the suction line from the tank to the inlet of the pump was squashed down in a couple spots causing a restriction.

Oliver 770 Industrial Tractor Part 106 - YouTube