Bench testing and resealing ARB locker

maulcruiser

maulcruiser

Well-Known Member
Joined
Aug 13, 2005
Location
Bladenboro/Wilmington, NC
I had to pull my 3rd member on my 8.4 Toyota as the ARB was pressurizing the housing. I could hear and feel air escaping from the vent. Of course, this all occurred after the diff was out of warranty. I just pulled the 3rd yesterday evening, so I've not sourced the air leak. Is there a common seal that fails? ECGS replaced the gears in the 3rd last year, but I didn't have it plumbed on the truck at that time to know if it was an issue. It can't be too much involved to bench test, right? Looking at ECGS's website, there's a seal housing, two o-rings, and a bulkhead o-ring that it could possibly leak from. The copper line appears intact and doesn't have any witness marks from rubbing. I'm in uncharted territory here, but with the videos online, it seems simple enough. Any further advice anyone could offer?
 
I've seen the bulkhead fittings leak and have heard of the seal housing o rings going bad. Get you a rubber tip air nozzle and check to see where it's leaking at. The bulkhead has an updated design from what it used to be that from what I can tell will be much better than the old. Seal housing o rings are easy to change if they're bad, just grease them and make sure they're not folded weird since they're a square cut. If it's neither of those then it'll be an internal leak in the locker. Never been in one but it shouldn't be awful to change.
 
I've resealed a ton of them over the years. I suggest getting the ARB air test manifold so you can accurately diagnose it before tearing it apart. The "big" internal seal generally doesn't leak unless there is a catostrophic failure. The seal housing orings tend to leak when not installed properly or preload is lost.
 
Jody Treadway said:
I've resealed a ton of them over the years. I suggest getting the ARB air test manifold so you can accurately diagnose it before tearing it apart. The "big" internal seal generally doesn't leak unless there is a catostrophic failure. The seal housing orings tend to leak when not installed properly or preload is lost.
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They had an updated square seal design also vs the original o-ring.

I've replaced a few.

Make sure to lube up the whole deal before assembling it.

The updated bulkhead is better/easier too IMO.
 
Jody Treadway said:
I've resealed a ton of them over the years. I suggest getting the ARB air test manifold so you can accurately diagnose it before tearing it apart. The "big" internal seal generally doesn't leak unless there is a catostrophic failure. The seal housing orings tend to leak when not installed properly or preload is lost.
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I feel like I could make this device considering ARB wants $110 for it. From tinkering with it yesterday, it was difficult trying to hold an air line to it while listening for air leaking.

Thank you all for your responses so far! I'll post up tomorrow with my findings or and other questions.
 
I decided to check the easy stuff first. I took the bulkhead fitting apart and noticed that the line is tapered down here. I suspect it's been loose and allowed to rattle around inside the bulkhead in the years prior to me actually completing the installation of the pressure lines. I did have a 2" piece of crimped air line on the fitting to prevent contaminating the internals.

Any of y'all seen anything like this? Best solution I can come up with is to either try and get as much slack out of what's left to remove that area, or buy a new seal housing kit.
 

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maulcruiser said:
I decided to check the easy stuff first. I took the bulkhead fitting apart and noticed that the line is tapered down here. I suspect it's been loose and allowed to rattle around inside the bulkhead in the years prior to me actually completing the installation of the pressure lines. I did have a 2" piece of crimped air line on the fitting to prevent contaminating the internals.

Any of y'all seen anything like this? Best solution I can come up with is to either try and get as much slack out of what's left to remove that area, or buy a new seal housing kit.
Click to expand...
Try to get some slack to it. If that doesn't work you might could get a compression union to scab in to add a new section (arb may have a fitting for this) Worse case you may have to get a new seal housing. I would go ahead and order the updated bulkhead fitting.
 
maulcruiser said:
I decided to check the easy stuff first. I took the bulkhead fitting apart and noticed that the line is tapered down here. I suspect it's been loose and allowed to rattle around inside the bulkhead in the years prior to me actually completing the installation of the pressure lines. I did have a 2" piece of crimped air line on the fitting to prevent contaminating the internals.

Any of y'all seen anything like this? Best solution I can come up with is to either try and get as much slack out of what's left to remove that area, or buy a new seal housing kit.
Click to expand...

They would crimp the copper line like that on the old style bulkhead fitting that used an oring on the copper line if you over torqued it, I don’t think it’s from the line rattling around. The 8.4 ARB routes the line along the bearing girdle so there is probably a way to get enough slack to pull the line thru another 1/2” to be able to reassemble the bulkhead fitting on a clean section of tube
 
Chris_Keziah said:
Try to get some slack to it. If that doesn't work you might could get a compression union to scab in to add a new section (arb may have a fitting for this) Worse case you may have to get a new seal housing. I would go ahead and order the updated bulkhead fitting.
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According to what I'm finding, what I have is the updated version: PN 170111.

Metto said:
They would crimp the copper line like that on the old style bulkhead fitting that used an oring on the copper line if you over torqued it, I don’t think it’s from the line rattling around. The 8.4 ARB routes the line along the bearing girdle so there is probably a way to get enough slack to pull the line thru another 1/2” to be able to reassemble the bulkhead fitting on a clean section of tube
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I was able to pull enough slack to cut off the last .5" and get to uniform diameter stuff. I need a new o-ring, but it was pretty straight forward.

I'll get an o-ring today and give it a test.

Thanks to you all!
 
maulcruiser said:
@Chris_Keziah I am now seeing a newer one that tees and has even more connections, but is for the 3.5mm black air line. Is that the one you're referring to?
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The one I was finding is for the 3.5mm copper and 6mm black air line. Old stuff was 3/16" and 5mm blue air line. Need to verify what size stuff is in yours.
 

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I have the 3/16" and 5 mm lines. I tested my repairs last night and it seems to be holding. I did not use the ARB o-ring, but found a thinner version at a hardware store. I don't have faith in it being a long-term repair, but it will do for now.
 
maulcruiser said:
I have the 3/16" and 5 mm lines. I tested my repairs last night and it seems to be holding. I did not use the ARB o-ring, but found a thinner version at a hardware store. I don't have faith in it being a long-term repair, but it will do for now.
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If you were closer to me I have about 100 of the replacement orings I had ordered when my old TJ still had the ARB in it. Can't remember if I found them on Amazon or McMaster, I'll look and see what they are in the morning.
 
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