Gear Oil Coming From Solenoid: 

3 Basic Causes:

1. Clogged axle breather vent:
The ARB Air Locker system naturally vents off slight amounts of pressure into the axle housing as the diff operates (hence the reason the compressor cycles normally every 4-10 minutes depending on O-ring condition). If the axle breather is clogged or blocked, it can create a high pressure situation inside the axle housing forcing gear oil fluid to penetrate the O-rings and into the air supply line. When the air line pressure is vented, this gear oil will be pushed up to the solenoid and out the release port. Check the axle breather for adequate passage, clean/replace as needed. Remove air line at the differential bulkhead fitting, purge line with compressed air and re-install. 

2. Overfilled differential:
Check for proper gear oil level in the differential in compliance with differential specifications. Remove air line at the differential bulkhead fitting, purge line with compressed air and re-install. 

3. O-ring failure:
Excessively worn or improperly installed O-rings on the Air Locker carrier can lead to gear oil penetrating the air system. When the air line pressure is vented, this gear oil will be pushed up to the solenoid and out the release port. Replace O-rings to correct problem.

Other Scenarios:
Damage to the seal housing:
Damage to the cylinder cap (seal surface for the O-Rings):
Damage to the adjuster nut:

Case Study:
Oil seepage from solenoid - We installed an ARB RD33/CKSA12 into the back of a 97' LX450 (80 Series Landcruiser), the locker was bench tested and held pressure prior to installation. The customer wired his own compressor, thus the axle had never even been pressurized on the vehicle while the problem started occurring. We started with the easiest solution first, which was to make sure the axle had adequate breathers. We added a much larger breather setup, cleaned the air lines with compressed air and then pressure tested the system again. Everything functioned as planned.

Approximately 2 weeks later, the customer was having the same symptoms again, small amounts of gearlube leaking from the top of the solenoid (discharge vent) as it sat overnight, regardless of whether or not the locker was operated recently. At this point we decided to go ahead and pull the 3rd member and inspect the o-rings and seal housing for any obvious problems. Upon disassembly the only thing we could see was looked to be a small "manufacturing" mark on the cylinder cap of the Air Locker... however it was minor enough that we felt comfortable reinstalling the locker with new O-rings. The locker was bench tested using 110 psi (far more than the operational pressure of the locker), it tested above and beyond ARB's specifications. We reinstalled the 3rd member, buttoned everything up and cleaned out the air lines, once again using compressed air. The locker functioned as planned, we probably cycled it a hundred time over the course of a day, each time it worked flawlessly. Problem solved?

Another month goes by and I get a call from the customer, I had actually called him the day before just to double check that everything was holding up as planned... bad news, the solenoid was "drizzling" lube once again, enough to notice and cause lube to be "sprayed" after disengaging the locker. I place a call to the tech gurus at ARB, hoping they could think of something that we had missed. We covered the diff breathers, o-rings, etc... the only thing he could thing of is that we didn't get the lube completely cleaned out of the locker assembly. His analogy was "oil on a table", you can blow it with air all you want, but its just going to coat the entire table. He recommended using some brake cleaner to clean all of the residual air out of the lines. This seems plausible, we had no way of knowing how much lube was inside the piston assembly of the air locker, not to mention all the residual lube inside the plastic line that didn't get removed by the compressed air method (using the compressor).

Our next step is to clear the lines one more time... this time using some brake cleaner and higher pressure to really clear everything out. However if the amount of fluid leaking stays consistent between now and the time we get the customers truck in our hand... this is likely not the issue. If that is determined, we will once again pull the 3rd member, this time paying VERY close attention to the minor "scars" we noted on the cylinder cap, I have another cap ready to go if that turns out to be the case. Stay tuned, if you have any suggestions/ideas let me know!!

To date this is the ONLY locker I have dealt with that has experienced issues as such, we have literally sold and installed hundreds of lockers over the past 10+ years, and while we have had some isolated issues with o-rings, nothing like this case. While o-rings have failed in the past, I am convinced this unit has some issue besides the o-rings. All things considered I'm still 100% sold on the Air Lockers!

UPDATE:
We went ahead and pulled the 3rd again, the amount of fluid coming from the solenoid was enough to prevent the locker from functioning. We replaced the cylinder cap, u-ring/bonded seal, and used the newly introduced "square" cross-section o-rings. Rechecked the system using our pressure tester, re-installed the differential, and again rechecked the pressure. The lines were purged and cleaned and reinstalled on the differential. Fast forward several months and it is dry as a bone!!!

TROUBLESHOOTING

Air Line Supply Disruptions:

3 Basic Air Supply Disruptions:

1. Compressor fails to switch on
- a. Electrical fault (most common, usually a fuse, wiring, relay)
- b. Mechanical fault in compressor (rare)
- c. Isolating switch fitted and not turned on (as in a aux. fuse block switch)

2. Compressor fails to switch off
- a. Electrical fault (pressure switch)
- b. Air leak (compressor trying to meet pressure switch req.)

3. Lockers fail to engage when button is pressed on
- a. Electrical fault (see part 1)
- b. Seized or leaking solenoid valve (easy to swap, relatively cheap)
- c. Mechanical fault in compressor (rare as mentioned before)
- d. Inadequate air line pressure.

Common Solutions:

1.a & 3.a:
- Check the battery terminal is connected
- Check all connections are secure, no loose or disconnected wires
- Check the fuse (system only requires one 30 amp fuse)
- Check pressure switch relay & dash mounted switches
(a simple multimeter/test light can be used for all testing)

1.b:
- If mechanical fault is suspected in compressor (return to ARB service center)\

1.c:
- Test all functions of isolating block with multimeter/test light

2.a:
- Check that pressure switch is functioning using multimeter/test light

2.b:
- Air leakage can occur at several locations in the air supply system for a number of reasons.
2.b.1 - Check all connections
2.b.2 - If leak is detected at fittings, remove, clean, apply sealant, and tighten.

3.b:
- Solenoid valves (Part# 180102 & 180103) can be disassembled and cleaned.
- Assemble onto compressor using hydraulic sealant (Loctite 569)
- If solenoid continues to fail, replace with new (or tested used) solenoid unit

3.c:
- If mechanical fault in Air Locker is suspected, remove differential and inspect

3.d:
- Using a pressure gauge on the line in question, measure the air line pressure. Pressure readings should match ARB specifications of 

ARB Compressor Fault Disagnosis Procedure:

COMING SOON! (email if needed)
 
 
 
 

Information contributed by:

Cruiser Outfitters

ARB Air Locker Servie Manual
September 2003

*See something missing, wrong, or incomplete? Please let us know!

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