Hydraulic Screech noise

[owner66]

I have an AC 5015 with a 'factory' FEL and 3pt. It's making a noise very much like a power steering pump low on fluid (it's not). I'v gone thru alot of threads, but most seem to be low on fluid, reaching stops, or binding, which I don't seem to have.

I have had this problem since I bought it a few months ago, and I THOUGHT it was due to the PO not performing regular maintenance on it. I only noticed it while using the FEL since I did not have a box blade. I just bought a box blade, same issue whether using the 3pt or the FEL. It doesn't only make the noise when at the stops, it can be in between. Using the 3pt, it may be say 1/2 way up an screeching, I can bump it up or down and it will stop, same with the loader. It does seem to do it more when I've just finished driving around especially the FEL. The hydraulic pump is much louder when using the 3pt.

Hydraulic valves are a 2 spool open center valve and a 2 position valve to use either the FEL or the 3pt., as well as an 'speed' control for the 3pt lift rate. It drains back into the tank, and there is a pickup pipe piping fluid straight to the pump thru the filter.

I have rebuilt all the loader hydraulics, installed a new 2 spool valve, gone thru all the fittings and replace o-rings and hoses where needed, tightened all pipe thread connections, changed the fluid and replaced the hydraulic filter.

 

[Jay4200]

I have an AC 5015 with a 'factory' FEL and 3pt. It's making a noise very much like a power steering pump low on fluid (it's not). I'v gone thru alot of threads, but most seem to be low on fluid, reaching stops, or binding, which I don't seem to have.

I had the same problem when I built my snowblower remote setup for hydraulic chute controls. You have a relief valve that is blowing off prematurely. The relief valve is squealing as it bypasses fluid. You should be able to track it down by ear. Mine was in my valve set. Turns out they gave me a valve that had an internal relief set too low. I cranked up the blow-off pressure, and it solved the problem.

JayC

 

[J_J]

Check the relief setting on the loader valve and the 3pt.

If all valves are in neutral, and you hear it, then I would suspect a QD or something pinching a hose or steel line. There should be very little or no pressure in neutral.

 

[owner66]

Finally got a chance to look a the service manual on this.
It says to adjust the set pressure by using a shim, 1mm shim = approx 200 psi.
So, would I need to possibly add a shim, or remove one?
Anyone know if there is a service port where I could hook a gauge?
Also, what's a good cheap gauge?

 

[J_J]

Hyd gages run about $10 to 20 at Northern, or Surplus hydraulics. If you have QD's, You can make up a gage and QD to plug into your QD's.

You could also install the gage in a tee at the IN port of the loader valve if you have a loader, and monitor the hyd system and use it for trouble shooting.

First you need the pumps max pressure, and then set the relief to about 50 to 100 psi below the pumps max pressure. Check the pressure and if you have to add some shims, use the smallest and see what the results are. It might take the smallest shim, or the whole pack.Good luck.

 

[J_J]

After you raise the 3pt, where do you leave the lever. If the lever stays in the up position, the 3pt is in relief, and making noise. The lever should be in neutral which is somewhere in the middle of the lever movement. Once you set the 3pt, move the lever slightly down to neutral, and see if it is still squealing.

 

[owner66]

Thanks again J.
I do have a qd to the loader circuit, i'll look at tapping in there once i can get a guage.
When I lift the 3pt, I max it out and it squeals. I can understand it squealing because it is maxed.
I can bump it down ever so slightly, and the squeal stops. What's strange is that it will also squeal at some positions in-between maxed up and all the way down. A simple bump of the lever up or down will stop the squeal in these positions.
I just want to make sure the squeal is not an indication of my causing damage to the pump or other parts, apparently they are hard to come by for this model.

 

[Leejohn]

If it comes to a pump, you might try these people West Kentucky Tractor Parts - Kevil, Kentucky
I just got a engine off of a MF 2010 for a Allis 5015. The engine didn't show many hours on it, had no ridge in the cyls and valve train was real clean. They took the pump off when I got the engine.

 

[RonMar]

Check your lines feeding the pump also, as well as the suction strainer if so equipped, to make sure it is clear. The noise, if it is comming from the pump could be from overload, or from a small air leak or a restricted supply causing cavitation in the pump when it comes under load.