My disco2 (00) is sagging at the rear when parked. I've read the issue on the forum and so went out to spray the air bags with soapy water to see which one was leaking. Unfortunately, neither one shows any obvious sign of bubbling..

Also, some times when we park the rear doesn't sag at all.

This leads to me think its the values at the pump, but I'm not sure.

1) When spraying the airbags is there any where in particular I should be looking for bubbles? Do they leak in non-obvious, non-visible places?
2) Is there any way to determine if one of the values at the pump unit is faulty? I took off the cover and put some soapy liquid on the air connections, but this doesn't test for leakage through the value. Any idea how to test for that?

I'd like to find out the area of the problem rather than getting stuck with a bill from the dealer for a new airbag only to find its something else.

 

How many miles on the truck? How long does it take it to leak, and does it come down evenily?
When you start the truck up will the bags lift up the truck within a couple of minutes?
Mike

 

It sags most on the driver side. Question is whether the leak is in the bag or in the value on the compress end for that bag.

Truck as about 90,000 miles on it.

The truck lifts up within a couple of minutes without problems. Compressor seems to run more than normal when up.

 

With that mileage your bags are undoubtedly brittle and could be leaking. The only way to tell for sure would be to have someone scan the SLS system for a fault code. It could be the bags, if so you should replace both. It could be the programing in the ECU may need to be reset.
I just recentl changed mine out because my drivers side bag would slowly settle over a couple days of sitting and it kept getting worse.
If it were mine I would go for a set of bags from, http://www.arnottindustries.com/ . They are far better then the factory bags, less money and come with a lifetime warranty.
The neat thin is they are very easy to change out, less then 30 minutes.
Mike

 

Yeah, I'm inclined to agree with you.

Can you read the SLS code out with an OBD-2 reader or do I need LR to do this?

I've read the instructions on the arnott bags.. Looks easy. Any suggestions for how to support the vehicle and axle? I've got jack stands, are they sufficient?

 

No, a standard OBD2 scanner can't read or reset the SLS system, need a test book or autologic type scanner.
A jack and 2 floor jacks is all you need.
Mike