OEM Locker Pump Cycling

[Duck Doctor]

Troubleshooting an issue with the OEM lockers in my 06 LJR and would appreciate some guidance.

Rear locker pump turns off and on repeatedly, basically cycling every couple seconds.

Front locker works 100% correctly. I hooked the front locker pump to the rear locker and the front pump cycles.

When I hook the rear pump to the front locker the rear pump works correctly.

So now that I’ve verified both pumps work correctly I’ve determined the issue is with the rear locker. Could a leaking air line cause the pump to cycle? Maybe the interior line is damaged and slightly leaking? Guess the issue could be the internal locker bladder.

Appreciate your help.

 

[JKP]

You have a leak somewhere.

Check the external hoses and the nipple that goes into the diff first.

If they are OK, remove diff cover and check the internal hose and the clip that holds it on the nipple.

If all those are OK, you actuator is leaking.

 

[AndyG]

One quick test is engage it- and remove the rear fill plug- if the line is off or degraded in the diff you will likely know it- an oily mist will come out -

Also the air bladder can fail- there are lockers out there- I think Rubicon Resurrection sells them, based in Colorado.

 

[Duck Doctor]

Appreciate the information and suggestions. I will report back tomorrow with the results.

 

[AndyG]

Appreciate the information and suggestions. I will report back tomorrow with the results.

It seems like it is most often the short line that is used inside the differential and it’s really easy to replace.

 

[Jerry Bransford]

Appreciate the information and suggestions. I will report back tomorrow with the results.

To isolate the leak between the the compressor and air lines and inside of the axle housing, remove the air hose at the top of your rear axle and cover the hose with your finger while the compressor is running. If the compressor continues to cycle you know the air leak is between your finger and the compressor. If the compressor stops cycling and remains off with your finger blocking the air hose, the leak is inside the axle housing.

Inside the axle housing there are two possible leak sources... the short air hose inside that connects to the locker actuator might have slipped off at either end, or the air bladder inside the locker actuator is leaking. The black rubber air bladder inside the locker actuator adjacent to the locker is what was leaking on my Rubicon.

 

[Duck Doctor]

To isolate the leak between the the compressor and air lines and inside of the axle housing, remove the air hose at the top of your rear axle and cover the hose with your finger while the compressor is running. If the compressor continues to cycle you know the air leak is between your finger and the compressor. If the compressor stops cycling and remains off with your finger blocking the air hose, the leak is inside the axle housing.

Inside the axle housing there are two possible leak sources... the short air hose inside that connects to the locker actuator might have slipped off at either end, or the air bladder inside the locker actuator is leaking. The black rubber air bladder inside the locker actuator adjacent to the locker is what was leaking on my Rubicon.

View attachment 418330

Great idea. Appreciate the info Jerry.

 

[Bigfoot15]

Troubleshooting an issue with the OEM lockers in my 06 LJR and would appreciate some guidance.

Rear locker pump turns off and on repeatedly, basically cycling every couple seconds.

Front locker works 100% correctly. I hooked the front locker pump to the rear locker and the front pump cycles.

When I hook the rear pump to the front locker the rear pump works correctly.

So now that I’ve verified both pumps work correctly I’ve determined the issue is with the rear locker. Could a leaking air line cause the pump to cycle? Maybe the interior line is damaged and slightly leaking? Guess the issue could be the internal locker bladder.

Appreciate your help.

To all future people who want to test this issue indicated. These air pumps generate an air pressure of 4.5 to 5 PSI MAXIMUM. (not a vacuum) That 4.5 PSI puts (via hoses) pressure on a fragile bladder inside your differential which forces basically pins to mesh both sides of the axels together creating the axel lock. NEVER put more than 5 PSI pressure on your bladder or they will pop. Both of mine on my first Rubicon were popped before I purchased my jeep and I had to replace the gear assemblies as I couldn't find replacement bladders. The previous owner didn't know that the air pumps had rusted their internal valves open and could not generate the 4.5 PSI. I searched for new pumps but discontinued and no stock. I now rebuild pumps from scratch. I've rebuilt about 50 pumps. I can replace internal solenoids, valves, switches, circuit boards, and I 3D-Print new carbon fiber covers. Lubricated, tested and warranted, $100 or less per pump typically to rebuild your pump. I have some stock on "pulls"/rebuilt, replacement pumps $300 each. Happy trails/climbing. Text 519 909 4298 Paul

 

[tworley]

Good to hear someone repair them but I think most people will buy the kia pumps or opt for a regulator nowadays.