[Kehyler]

Hi all,

I spent an hour or so trying to diagnose a problem, but didn't come up a solution. Below are the symptoms, anyone have a suggestion for a fix?

• Rear locker pump is cycling on about once per 2 seconds
• Pinching off air hose right at the pump increases the rate at which the pump comes on
• Rear locker engages
• No damage is visible along the air hose, even the short line inside the differential

My conjecture would a bad rear air pump. Any possible way to diagnose/repair or just jump to replace at this point?

Thanks!

 

[DAA]

Sounds like you have done a pretty good diagnosis already. Switching the pumps would only move the symptoms to the front, but I guess that would be one way to further isolate the pump as the problem.

- DAA

 

[johncanfield]

^^ That's my guess as well ^^ If you pinch off the air hose and it continues cycle that's a bad pump.

 

[Kehyler]

What about installing a t-fitting on the front air line, in-line with the front & connecting the third connection to the rear locker hose? The upside is that it could give me my rear locker back, the downside would be that I would only be able to use both simultaneously or neither at all.

 

[Ken White]

Are you sure the rubber hose is good and/or making a good seal to the nipple? If I remember correctly, the pressure is 5 PSI so you should be able to hold your finger on the nipple to see if it is generating the pressure and if the internal check valve is working correctly.

 

[Kehyler]

Are you sure the rubber hose is good and/or making a good seal to the nipple? ...

Not fully, I visually inspected the rear one (I could only see about half of it) and it looked OK. I should probably check the entire line around the nipple before I get too excited. I pinched it off about 6 inches from the nipple.

What do you think about my idea of installing a t-fitting and using the front compressor to pressure both lines simultaneously?

 

[Ken White]

I am pretty sure one pump will lock both without issue.

The only problem I see is that without independent control, both will need to be unlocked during tight maneuvering or you will bind the front axle u-joints and risk their failure.

Just something to think about.

 

[BobsLJ]

Agree with Ken. Find the issue, fix it right. You’ll be glad you did.

 

[Kehyler]

I am pretty sure one pump will lock both without issue.

The only problem I see is that without independent control, both will need to be unlocked during tight maneuvering or you will bind the front axle u-joints and risk their failure.

Just something to think about.

That's an avoidable situation because I could just unlock both lockers to do tight maneuvering.

Agree with Ken. Find the issue, fix it right. You’ll be glad you did.

In the even that my rear pump is non-repairable, I am wondering its worth the possbily >$100 to replace.

In any case though, does anyone have sources which describe if the locker pumps are repairable?

 

[Kehyler]

This weekend I plumbed both off the front pump. They both appear to lock together.

 

[johncanfield]

If you offroad very much you really don't want to lock both axles all of the time when on the trail. I use the rear locker only about 90% of the time. With both axles locked it can be very hard to make a tight turn on any surface except dirt or gravel.

 

[FLLJ]

In any case though, does anyone have sources which describe if the locker pumps are repairable?

Now that you determined the pump is the culprit maybe this can help get you back to stock.
How to repair a locker pump

 

[Kehyler]

Now that you determined the pump is the culprit maybe this can help get you back to stock.
How to repair a locker pump

I had actually read that before deciding to plumb them both off the front. From the text, I couldn't really understand what I was supposed to be doing. Does anyone have some pictures?

 

[Kehyler]

If you offroad very much you really don't want to lock both axles all of the time when on the trail. I use the rear locker only about 90% of the time. With both axles locked it can be very hard to make a tight turn on any surface except dirt or gravel.

I would consider myself a rather technical offroader, and I have not yet had a situation where I think I needed only the rear engaged. Such a situation would be (1) need to make a tight turn and (2) am stuck without lockers.

Of course, I have used the rear locker independent of the front many times. I'm just not sure that I've needed it.

I'm actually somewhat open to diagnosing the rear pump, I just couldn't understand the instructions clearly enough to pursue it at the moment.

 

[johncanfield]

When I'm in a large group or trail leader I'll lock both axles on an obstacle so I can get up and over and not hold up the group. Sometimes I'll lock just the front axle which can help on a climbing turn - a "front dig." Without a two stick Atlas it's not a true front dig but close enough.