Hi, I was jacking up the GL320 to put rear break pads on and one of the shocks started leaking. This also happened a few years ago when replacing one of the air bags. Is there some sort of jacking procedure I am missing? I did not see any special instructions in the user's manual.

 

Do you mean the actual shock absorber, or the air spring?

I'd guess your rear shocks were about end of life anyway, and pulling them to full extended position stressed the seals.

You don't get more than 100k miles out of the rear shocks.

 

There is not, you did it right - rear bags were as Eric said, at end of life.
The good news is: If you can do brake pads, you can do rear air bags. About 15 minutes a side while you have it up there and the wheels off.
Recommend Arnotts.

Max