I don't ever recall the self leveling suspension working as described in other posts. The suspension doesn't automatically go up or down. Recently I been hearing a "hissing" noise comming from right rear near accumulator & level controller when the engine is running. However, with engine off, the system will raise & lower both sides when the level control arm is manually operated (connecting rod disconnected).

I removed (black fluid) and thoroughly cleaned resivour, refilled with new fluid and operated system to evacuate old fluid from lines. Level remains constant.

* Other than using a pressure tester, is there a method to determine what item is malfunctioning, level controller vs accumulator(s).
* Does the "hissing" sound indicate a bad accumulator or level controller?
* If one accumulator is bad, should I replace the other as well?
* From underside, there appears to be 3 nuts securing the accumulator. Or is there something else securing it?
* Left side is reasonably accessible, what's the secret to accessing the right side?

Bob