Suspension problem
1997 Buick Lesabre 6 cyl Front Wheel Drive Automatic 130000 miles

The car rear end has assumed a increase in height and
now slopes down in the front.

I have been told this may be an issue with control of
a (the) air pump associated with the "air ride".

That there is no apparent adjustment for this problem.

Any advice will be appreciated.

How canI isolate the cause the problem?

Are the above statements correct?