HT4100 4.1, 4.5, 4.9 Discussion, Checked your A.I.R. system filter lately? in Cadillac Engine Technical Discussion; I just checked mine, and it literally crumbled in my hand. It's a soft foam filter with a metal grid ...
I just checked mine, and it literally crumbled in my hand. It's a soft foam filter with a metal grid inside to hold its shape. It's about the size of a pack of cigarettes, and has a light coating of oil on it. The idea is to trap particles from intake air before they reach the air pump. I have to believe that a clogged (or rotten) filter is a leading cause of pump failure.
On the c-body DeVille, it's in a little black plastic box, next to the A/C accumulator. The lid just pops off. The AC Delco replacement is about $9.00
Not sure if there's a cross reference to any other filter company, but it's available anywhere AC/Delco is sold. I'm fortunate to have a great little family owned parts store just down from my office that sells everything Delco ever made.