Internal leak ARB air locker (1 Viewer)

sandcruiser

....back in the saddle again....
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talk about frustration....

for a few months now I've been very very slowly installing my rear air locker. Did the diff some time ago (months), then installed the compressor just last month, then did the switches about a week ago, and most of the electrical wiring as well.

Today I finally did the air line to the diff itself. Nearly screwed myself by breaking the ferrule that holds the blue line to the diff... but found an old, broken one, and scavenged enough bits from each to make a good fitting.

Fired it up to test... and the pump just keeps running.

The locker does engage and disengage. That part is good!
But the pump can't get to the shutoff pressure as the air just continues to flow.

The fittings from diff to airpump are all good, and I can hear air rushing out of the diff breather, so I guess the leak must be in the locker itself.

I plan to tear into it in the next week or so. Anyone care to predict what I might find or make suggestions of what to look for?

I'm predicting bad Orings, which stinks, because I used new ones when I did the install. But is there anywhere else it could be leaking?

I guess the copper tube could be cracked, or the fitting on the inside of the diff, perhaps.

Does this mean I have to tear down the diff all the way? or just pull the pumpkin?

Poop.
 

LC4LIFE

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First thing I would do is make sure the airline fitting at the 3rd member is not leaking. It is very easy to over tighten the fitting and that may cause a leak. If you verify the leak is not there, then you have to pull the 3rd, but you will not have to tear down the diff. Check the locker o-rings as they can twist during assembly also causing a leak. Just connect the airline to the 3rd and make sure it is all working and sealed before reassembly.
 

sandcruiser

....back in the saddle again....
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Thanks for the input.

I'm sure it isn't (just) the fitting outside the diff... I can hear it whistling up the breather tube, and if I pinch the breather, it changes pitch.

Also, when I switch it off.... it takes a while to breath out at the solenoid and smells like gear oil.

I'll plan to pull the 3rd soon to take a look.
 

mca

Joined
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Southern California
Did you ever resolve this issue?

I'm having a similar problem with a TJM air locker on my 100-series. The compressor either runs continuously or cycles every 5 seconds. I can hear the air leaking out the diff breather line. I can alter the pitch of the leak by manipulating the small brass fitting on the end of the breather line.
 
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My bet would be you hit the line when you installed the third member, or the stupid solder joint has a pinhole. Spend hours with a spray bottle and soapy water first...just my 2 cents.
 

mca

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My bet would be you hit the line when you installed the third member, or the stupid solder joint has a pinhole. Spend hours with a spray bottle and soapy water first...just my 2 cents.
i didn't do the install, I purchased the truck this way. Both I and the seller thought it was an air line leak somewhere along the frame. I'll get underneath with some soapy water and a spray bottle. The air definitely comes out the end of the diff breather line. which solder joint are you referring to?
 

Cruiserdrew

On the way there
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If this is a used air locker, there are several possibilities. An air line pinch is a good guess, the o-rings may have been twisted on install, or the internal bonded seal can fail.
 

baldilocks

Battle Ground, WA
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Did you ever resolve this issue?

I'm having a similar problem with a TJM air locker on my 100-series. The compressor either runs continuously or cycles every 5 seconds. I can hear the air leaking out the diff breather line. I can alter the pitch of the leak by manipulating the small brass fitting on the end of the breather line.
I would start by replacing the tiny O-ring at the bulkhead fitting accessed from the outside of the housing.

This O-ring fits around the copper tube. If it is bad, air can leak between the copper tube and hole inwhich it passes through the axle housing.
 
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Hi,

I am super lazy, so will always start with things that require little or no effort. In terms of air lockers, I would:

  • Check the connections (soapy water, etc..)
  • Check the line (soapy water, etc...)
  • If u find a leak, fix it
  • If u don't find a leak, pull the line, retorque the fittings with new seals at both ends and run a new airline
  • If that fixes it, you know it was a leak that you didn't find. If it doesn't fix it, pull the diff and do the hard work knowing you have a new line


Just be super methodical, like any troubleshooting, fully eliminate a variable before you move on to the next.
 

Dave 2000

Not all Land Rovers are useless!
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PITA air leaks on lockers, my only reason to stick with OEM electric versions. My experience is O rings or the solderIng on the tube. Only once seen a rubbed through area on the copper tube, that is easy as a quick clean and dab of solder.

It's the bloody stripdown that's a nuisance!

Regards

Dave
 
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My ARB rear has an intermittent leak, sometimes it’s fine, sometimes it leaks out of the breather. I feel like it has to be one of the two o rings that ride on the locker(vs a snagged copper tubing), I was super careful when I installed them though. They’ll be coming out in a few weeks when I re-gear the diffs.
 
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My ARB rear has an intermittent leak, sometimes it’s fine, sometimes it leaks out of the breather. I feel like it has to be one of the two o rings that ride on the locker(vs a snagged copper tubing), I was super careful when I installed them though. They’ll be coming out in a few weeks when I re-gear the diffs.
reviving this not much information of causation with intermittent leaks, greg did you come to a conclusion on your intermittent leak? Ive got a similar issue with my 100 series and have noticed they lock and seal just fine when the dif fluid is hottest, which is problematic on the trail when the oil cools and they start leaking to the point where they wont lock at all. Ive pulled the rear third to bench test and could not get a failure to happen, did inspect the bulk head and seals. Im leaning on air supply but will be a while before I can get an air tank in the truck to ensure enough volume (im using the smallest ARB compressor with a good bit of length on the line. Contacted ARB and they didnt offer up many solutions or possible failures outside of the normal bulk head install error, but were not hesitant at all to send new bonded seals ( both front and rear doing this ) but before I spend 20+hours redoing this gear install Im interetested in others input.
 
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reviving this not much information of causation with intermittent leaks, greg did you come to a conclusion on your intermittent leak? Ive got a similar issue with my 100 series and have noticed they lock and seal just fine when the dif fluid is hottest, which is problematic on the trail when the oil cools and they start leaking to the point where they wont lock at all. Ive pulled the rear third to bench test and could not get a failure to happen, did inspect the bulk head and seals. Im leaning on air supply but will be a while before I can get an air tank in the truck to ensure enough volume (im using the smallest ARB compressor with a good bit of length on the line. Contacted ARB and they didnt offer up many solutions or possible failures outside of the normal bulk head install error, but were not hesitant at all to send new bonded seals ( both front and rear doing this ) but before I spend 20+hours redoing this gear install Im interetested in others input.
Never came to a conclusion, still happens intermittently, but less often it seems. I did have one time where diff fluid got into the air line all the way back up to the solenoid valve. I cleaned the line out with brake parts cleaner and it’s been fine since. One of my buddy’s rigs(Jeep) has started doing the same thing where it intermittently leaks.
 
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One of the things you an do to minimize leaky air lockers is to regulate down the pressure. I have found that the pressure switch that ARB supplies can be set too high. On my 91, the lockers locked reliably at 68 to 70 psi. That is considerably lower than the 95 psi that the ARB pressure switch would kick off at.
 
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One of the things you an do to minimize leaky air lockers is to regulate down the pressure. I have found that the pressure switch that ARB supplies can be set too high. On my 91, the lockers locked reliably at 68 to 70 psi. That is considerably lower than the 95 psi that the ARB pressure switch would kick off at.
FWIW, I think I have my compressor(ARB twin) set to 135psi(compressor on) and 150(off), I recall asking about the pressure being too high when I installed it but was told higher pressure is preferred(not to say that opinion is/was right).
 
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i heard about 100 series having a TSB issue with leaking arb lockers. if you installed it yourself, they tell you to pound sand. If a shop installed it they will warranty it. Just hear say while on a trail
 
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FWIW, I think I have my compressor(ARB twin) set to 135psi(compressor on) and 150(off), I recall asking about the pressure being too high when I installed it but was told higher pressure is preferred(not to say that opinion is/was right).
The "correct" pressure is the pressure the lockers can lock reliably. Once that pressure is reached, higher pressure is just higher pressure for no reason.
 

baldilocks

Battle Ground, WA
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My arb’s are 9 years old and well used. The only air leak I’ve had was at the compressor due to there being no O-rings at each end of the tank. I bought the rig with the lockers already in it so I have no clue why those O-rings, which are on the parts diagram, were not there. I found O-rings at Lowe’s that we’re the correct size. I haven’t had a problem since.
 

Cruiserdrew

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My arb’s are 9 years old and well used. The only air leak I’ve had was at the compressor due to there being no O-rings at each end of the tank.
Regardless, you will still have problems. ARBs need to be resealed periodically. I've had ARBs in different trucks for 18 years, and in the end, they will all leak air. Just the nature of it. I like the lockers but not the every 5-7 year rebuilds. Very good lock up, but total pain in the ass when not 100%. And that's not to mention the design changes and unavailable parts. And the oil coming up the solenoids. I would never buy another, and I've bought at least 6 of them new. I still use ARBs, like ARBs, but I am done with the leaks, and the oil and the BS they generate. I have heard the newer ones are less problem prone, and my experience backs that up, but still. Great lockers, high maintenance. And it has nothing to do with a "proper install". You drive ARB lockers for 75K miles and use them here and there, and they will eventually need to be rebuilt or replaced. You need them once a year for 5 years, you're likely OK.

I still have ARBs in 2 trucks, and they work great. I just know that in the end, i'll be working on them.
 

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