How to adjust a relief valve?

Cord · Apr 1, 2015

I put a gauge on my skid steer and confirmed that my relief valve is opening a couple of hundred psi too low. I know the relief is part of the valve assembly, but I don't know what it looks like or how to adjust it. Any suggestions?

narampa · Apr 1, 2015

Cord said:
I put a gauge on my skid steer and confirmed that my relief valve is opening a couple of hundred psi too low. I know the relief is part of the valve assembly, but I don't know what it looks like or how to adjust it. Any suggestions?

Post a picture of the valve they all are not the same.

/pine · Apr 1, 2015

Most have lock nuts....some are as simple as loosening the lock nut and adjusting with a screwdriver...
Others require adding shims/washers on top of the springs...

A good picture will get you detailed advice...

J_J · Apr 1, 2015

You have either an adjustable relief valve or a shim adjustable relief valve.

To adjust the adjustable relief valve, install the hyd gauge, run the engine so as to get about 10 GPM flow.

Remove the cap nut and loosen lock nut and then max out a cyl to read max pressure , and then if low, turn screw in to raise the pressure. Set lock nut cap nut back on.

If relief valve has shims, your dealer will sell you a set of shims.

Install hyd gauge.

With engine off, remove the cap nut , remove the lock down nut and install the correct shim to bring the relief pressure to specs.

narampa · Apr 3, 2015

I agree with JJ but there are so many different designs. If you feel he has supplied enough information go for it. Let us know how you make out.
If you can't do it with the information you have, post a picture. If you had to ask how, I would suggest you post a picture.

Cord · Apr 3, 2015

narampa said:
Post a picture of the valve they all are not the same.

I was going to do this last night, but it slipped my mind. Put a reminder into my phone to do this tonight when I get home.

Cord · Apr 3, 2015

Well, this is the best pic I can get without tipping the cab. Hopefully it helps.

J_J · Apr 3, 2015

Most relief valves are on the top of the valve by the spool lever.

Here is an example of the relief on a valve.

3 SPOOL 17 GPM KYB OC VALVE

Cord · Apr 4, 2015

Where is it in the photo?

J_J · Apr 4, 2015

The Acorn nut assembly on the left of the valve.

Your relief valve is usually close to the IN port.

Cord · Apr 4, 2015

That's what I thought. I took mine off and found a screw under the cap. Turning it in didn't change the pressure. Honestly didn't know what the screw was supposed to do. There is another section to the left and this one looks simular. When I take the cap off I don't have a screw under it.

narampa · Apr 6, 2015

Cord you have posted a picture of the control valve. That is not the relief valve.
Did you take a spool cap off? Not sure what you are referring to when you say you removed a cap.
If you are afraid to lift the cab you had best take it to a shop.
From the looks of your picture I would suggest you lift the cab and give it a bath.

J_J · Apr 6, 2015

Can you show a picture of the relief valve which is on the top of the valve where the lever connect to the spools.

When you say you were adjusting something, did you have a hyd gauge in the system and were the cyl's maxed out.

Cord · Apr 6, 2015

Per the manual, the relief is part of the control valve. When I was talking to my dealer, they said to adjust the relief on the far left section, but I don't see a set screw there. There is a relief at the second section, but per the dealer this just adjusts the lift circuit relief. I was testing the relief using the curl feature and adjusting this set screw did not change the pressure setting. Yes, there is a gauge on the machine. Currently the relief is opening at 2500 psi. Per the manual, this is supposed to be 3,000 psi.

J_J · Apr 6, 2015

That is where the relief valve should be.

Is this the first valve off of the pump?

You could also have a no relief plug in place of a normal relief valve.

If there is one relief valve in the circuit on the first valve in the series flow, every valve does not have to have a relief valve. The one relief valve will protect the pump.

Independent hyd circuits can have relief valves such as the work ports on a valve.

narampa · Apr 7, 2015

JJ
i'm a bit confused.What do you mean by a relief plug?
The picture he posted is really not that clear. It kinda looks like the type that you release a lock nut than turn the body and than tighten the lock nut. Or as you say split the body and add a shim.I have worked on that style with some old RexRoth systems. It is hard to tell with the picture,any Ideas?

J_J · Apr 7, 2015

You had me confused by some of your statements.

I think you have mislabeled the lines and fittings.

Most valve reliefs is close to the IN port.

That is the IN port you have label lift with float, and the relief valve has the acorn cap on it.

Exactly what is under the cap?

Don't know you are pointing to the far left.

Did you do exactly what I said on how to check the relief pressure.

Loosen the cap nut and lock nut

If that is an adjustable relief valve , after you start the engine max out the lift cyl and hold it to max.

This will show what the cyl is developing as to pressure, and if you turn the adjusting in, the pressure setting will rise.

If it is not adjustable, and uses shims, then you need to add shims to set a higher pressure.

There is no spool with relief valve. If a spool has a relief valve, it will be associated with a work port.

Forget the no relief statement. If your FEL is the first valve in the series flow path, it has to have a relief valve, and will set the relief for the hyd for most conditions.

You have two spools, and one of them is not aux. One is lift with float and the other is curl.

Cord · Apr 8, 2015

The drawing is correct. Supply is on the far left with three spools. Per the dealer the lift has a circuit relief. The main relief should be to the left, but when I took the end cap off there wasn't a set screw under it.

Tx Jim · Apr 8, 2015

J_J said:
You had me confused by some of your statements.

I think you have mislabeled the lines and fittings.

Most valve reliefs is close to the IN port.

That is the IN port you have label lift with float, and the relief valve has the acorn cap on it.

J_J
The valve section labeled in Cord's photo labeled "lift with float" has 2 steel lines attached to that one section so I think it's not the "in Port".

J_J · Apr 8, 2015

Well, it is not a spool valve and it is close to the IN port, and I don't see any other something that looks like a relief valve.

Cord, can you get a name or model number from that valve.

or

Wash it down and get some better pictures.

It is possible to have the IN port and an OUT port on the same end plate, and a relief valve also.

Looking for a picture.

3 SPOOL 20 SERIES PRINCE STACK VALVE OPEN CENTER

Better pic showing both tank and IN port with relief valve above.

5 SPOOL 20 SERIES PRINCE STACK VALVE OPEN CENTER

Click on second picture.