ARB front locker (disconnected air line) (1 Viewer)

[pfran42]

A while back I had front and rear ARB air lockers installed as well as the ARB CKMA12 high capacity compressor (Not the new high CFM model). When I would go to lock the diffs I would:

-Turn on air compressor (hear compressor motor for 1-2 seconds)
-Turn on rear locker (hear compressor motor for about 1/2 a second)
-Turn on front locker (hear compressor motor for about 1/2 a second

If both diffs were locked for an extended length of time (3-5 min), you would hear the compressor kick on for about 1/2 a second every 3/5 minutes. I am assuming this is normal operation.

On to the issue...

A few weeks ago the front locker stopped functioning. I could power the compressor, engage the rear locker but when I would hit the switch for the front, the compressor would just stay on. I assumed I had a leak, kept the front locker switch in the OFF position and only used the rear.

I finally got around to looking at it today and upon checking for snugness of the brass fitting that houses the air line connected to the diff, I gently tugged at the air line and it popped right out. I went to a hardware store, got a new ferrule, reassembled the fitting and reattached it to the diff. During the entire repair I referenced the installation manual provided by ARB.

Here is the "issue". Now when I engage the lockers I:

-Turn on air compressor (hear compressor motor for 1-2 seconds)
-Turn on rear locker (hear compressor for about 1/2 a second)
-Turn on front locker (no sound)
-Turn front locker off then back on (hear compressor for about 1/2 a second)

I thought it odd that I now have to play with the locker switch to get the compressor to kick in. To further test the system I connected my auxiliary air fill up hose (so that I could drop the compressor pressure on-demand) and repeatedly tried the full cycle of getting both front and rear lockers to engage. The front locker consistently required two or more on/off cycles in order to get the compressor motor to turn on. On the third test cycle, I experienced the same issue with the rear locker. I turn the compressor on, hit the rear locker switch and nothing. I rocked the switch back and forth and it turned on the air compressor.

One of my questions is, if I had a small air leak since day one (which I am assuming I did since the blue air line came out of it's fitting with next to no effort), does a fully operational front/rear ARB air locker system ALWAYS cause the compressor to turn on when flipping the buttons for the rear and front?

I am not 100% certain that I actually have a "problem" yet. All of my testing was conducted with engine on in park. I never moved the vehicle during locker testing so that I could hear the click of the lockers engaging. I'd like to hear some feedback from those of you with the same setup so that I know what "normal operation" is.

 

[pkelly72]

I had front and rear air lockers in my 80.

I would turn on the compressor and it would cycle
I would engage the rear and the compressor would cycle
I would engage the front and the compressor would cycle 50% of the time

Turn off the front...pshh
Turn off the rear...pshh

Lock the rear compressor would cycle....

 

[farinvail]

My ARB front does not always result in hearing the compressor run for the 1/2 second, but frequently does. If that is any help to you.
I'd throw a floor jack under a front wheel and lift it off the ground with t-case in N and parking brake on. Turning the tire by hand will result in front drive shaft turning. Flip switch, you should no longer be able to turn tire(due to locked diff)

 

[elkaholic]

Paul -

The compressor will kick in only when the pressure drops below 80 psi (as I recall). In the past, I had a heep and rant ARBs in both the stock axles and the 60s that I later installed. This was 12 years ago when ARB's compressors were fairly small. The volume of air required for the rear locker would cause the compressor to cycle on every other locker application. The front (with a much shorter hose run) would cycle the compressor every third application. This is perfectly normal.

When I later added a small air tank to the system, the compressor would run for a while when I first started it to pressureize the system, then would not run for quite a few locker application cycles due to the added volume inthe system.

The ARB compressor is essentially a miniature version of a shop compressor with tank. The compressor only ruins when the pressure in the tank drops below the setpoint.

 

[pfran42]

Thanks for the input. So I guess from what everyone is telling me, I had a small leak in the system since day one (since I was completely accustomed to the compressor engaging every time I turned on the front air locker).

 

[elkaholic]

Not necessarily. If you engaged the lockers rear first, then front, the combined volume requirement of air might have been enough to drop the pressure in the system below the pressure switch's cut in point. However, since you found a loose connection, you probably did have a leak.

 

[Nottajeep]

Thanks for the input. So I guess from what everyone is telling me, I had a small leak in the system since day one (since I was completely accustomed to the compressor engaging every time I turned on the front air locker).

Did you get some type of labor warranty from ACC?

 

[pfran42]

Did you get some type of labor warranty from ACC?

Officially, I don't know. As a customer who knows all of them, I am certain that they would have addressed the issue no questions asked. It just happened to be something that I could tackle so I never mentioned it to them. I have progressively become more demanding of the truck and I could totally see a branch or something getting wedged in a manner where it would pull on the air line right were it connects to the diff.

It is still noteworthy that the compressor activation behavior is different now when compared to how it functioned prior to breaking the front. I tested it on the trail today and the compressor definetely kicks in a lot less now.