Troubleshooting Rubicon lockers

BCB75

TJ Enthusiast
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York, PA
I will have more time to test after work later today. I have attempted to engage them on gravel while creeping in 4lo, but the lights never stop blinking. After some research, I realize I should have been doing a bit of turning to help them align.

I also did the test where you engage them in 4lo with the engine off. I can hear both pumps run, but neither ever stop running. Should they stop running once pressure is built up, even if the lockers never engage? If so, this would indicate either a broken pump or broken air line? Assuming pressure is being made, could the pressure switch be out, and is that part of the pump?
 
First, you have a leak somewhere as evidenced by the compressors never shutting off. They will continue pumping until the pressure builds up to 5 psi. The pressure switch is inside the compressor. Put your finger over the compressor's output nipple while the compressor is running. If the compressor shuts off the problem is NOT with the compressor. Start pinching off the hose at various points between the compressor and locker until the compressor shuts off... you have isolated the source of the leak.

You can also remove the compressor hose from the top of the axle. With the compressor running, pinch off the end of the hose so air can't get out. If the compressor stops running the line is air tight between the compressor and the nipple on top of the axle housing. That means the air leak is inside the axle housing. Either the short air hose inside the axle housing between the nipple and locker is defective or it has slipped off, or the bladder inside the locker's actuator is leaking.

Don't throw compressors at this problem until you have isolated source of the air leak which is NOT hard to do.

P.S. Thanks Jerry!
 
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Thank you, makes perfect sense. I wasn't sure where the pressure sensor was located to shut off the compressor. I will start by removing the output hose at the compressor and plugging with my finger to see if it shuts off. Odd that both are leaking at the same time. Especially since the seller said he just tested them and they both work. Oh well.
 
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Thank you, makes perfect sense. I wasn't sure where the pressure sensor was located to shut off the compressor. I will start by removing the output hose at the compressor and plugging with my finger to see if it shuts off. Odd that both are leaking at the same time. Especially since the seller said he just tested them and they both work. Oh well.

Be careful, the plastic can get brittle with age. Dont break off the nipple. Maybe use a razor to slice the hose and peel it off the nipple. Hope you figure it out. I have a slow leak on my rear I need to address, compressor will cycle every 30 seconds when my rear locker is engaged.
 
Well, both hoses at the axle sides were cracked pretty good and fell right off with minimal wiggling. Unfortunately, the rear came off with a bunch of the nipple still in the hose. I swear I was being gentle. So what now, toast?
 
Well, both hoses at the axle sides were cracked pretty good and fell right off with minimal wiggling. Unfortunately, the rear came off with a bunch of the nipple still in the hose. I swear I was being gentle. So what now, toast?
Drill it and tap it, or drill it and have it brazed or welded in? Do some searching, certainly not the first time this has happened. Found the issue at least, halfway to a fix now.

Found a post about someone drilling it out and using a piece of brake line to replace the factory nipple. Seems there are options.
 
For some reason I thought the nipple was part of the axle housing. Looks like they do make replacement parts, but they are plastic and overpriced. Can you just jam the new one in without opening the diff cover?
 
For some reason I thought the nipple was part of the axle housing. Looks like they do make replacement parts, but they are plastic and overpriced. Can you just jam the new one in without opening the diff cover?
Either way you will need to open the diff cover to connect the hose that goes to the locker bladder. The part appears to be pressed into the housing. Looks like 05083663AB is the Mopar number for the OE part.
 
Cool, thanks guys. I'll probably get new hoses while I'm at it. I work at a pneumatics distributor, so I can probably just take some stock.
 
Yikes, I would much rather spend 35 for a new fitting than deal with that process. More worried about how to install it, than how to avoid buying the part.
 
Yes, I meant using my work for the hoses. I will purchase the mopar fitting. Probably 2 while I'm at it, even though the front held together.