August 22nd, 2006, 11:04 AM
well got me an ARB in the front end and its all wired and tubed ect but i cannot get this thing to LOCK its not leaking all the way to the brass fittings and its not leaking at the Seal near the bearing caps anyideas??

August 22nd, 2006, 11:31 AM
Is it installed or are you bench testing it? Got oil in the diff or is the cover off to observe? You need to rotate the axle shaft to allow it to lock into place.

How much pressure are you putting to it? They require about 90 psi.

Just some starting thoughts..............

August 22nd, 2006, 11:43 AM
Its in the Axle Cover now on but was off before
I have even tried it while driving but the compressor just keeps running its an ARB locker ARB compressor

August 22nd, 2006, 01:23 PM
If the compressor keeps running, I would think the problem would be in a couple different areas. Disconnect the line right at the locker to verify flow AND pressure. You need both. If the locker itself is leaking, you will hear it with the cover off. So, if you have pressure and flow at that point, you know it is somehow in the locker and you need to look for the air leakage. Soapy water works good if you can't hear or feel it.

Now, the inverse is this. If you DO NOT have pressure and flow at that fitting, you need to back track to see if the compressor is putting out the required amount of air. Disconnect the line right at the compressor. Do you have flow and pressure?

Remember, an ARB need about 90 psi, so just because you have flow does not mean you are getting the desired pressure. That could be why it keeps running........ because it can not generate enough pressure to fire the pressure shut off switch.

IMO, I would start right at the compressor to verify it is building pressure.

Either way, you need to know that A) the compressor is putting out what it should, and B) it is reaching the locker.

By the way, is this a used or new unit?


August 22nd, 2006, 04:37 PM
To add to what Jim mentioned...

If the compressor keeps running, there may be an air leak... I know that seems obvious, but....

August 22nd, 2006, 04:46 PM
Yeah we checked the obvious. The air compressor shuts off by it's own pressure switch. But when the solenoid is open for the ARB it just doesn't shut off. No leaks can be found using snoop. I can pinch the air line right before going into the diff and the compressor will shut off. We just put new orings on and those are not leaking. Do these things have a reputation for leaking internally besides the orings?

August 23rd, 2006, 09:11 AM
Well, it sounds like you have traced it to the diff. Now, a couple more things. Is this a new or used unit? In some of the older ones, there is a releif valve that allows the air to exhaust into the diff when you turn it off. The reason for this is to not force the air all the way back to the compressor and out thru the valve.

I had a problem with this valve a couple years ago. Turns out that a little bug (yes the 6 or 8 legged kind) got into the valve and would not allow the spool to shift. It actually pressurized my diff and I was pumping diff fluid out thru the vent tube. But, it doesn't answer your question about why you can't hear air leakage.

Maybe you could put a larger volume air compressor onto the line to force more air flow. In this way, you might be able to hear the air.

It sounds to me like the main o-ring is blown and you have such a large area that the air is leaking out of that you can't hear it.

Sounds like the carrier needs to come out onto the bench. :angry2: