AC Rebuild - Part 4 - 09/20/2018

The AC cooled quite well... for 2 weeks. Freon ran low. Dammit... had a leak. Checked it out with soapy water and found out where it was leaking: the AC manifold at the muffler fitting. Since it was already damaged when I removed the old hose and I took a chance... turns out I lost. Oh well. Time to order a new one! Except no one makes a replacement hose for a 1989 Cadillac full size. That's quite annoying. I investigated other car lines since the Olds 307 and the GM B-body ran from 1977-1990, I had a decent amount of cars to look for. I eventually found a 1981-1985 Olds Custom Cruiser with a 307: the manifold was slightly different (muffler is larger and curves at a different angle than the Cadillac version). I have no clue why they're different, but if you look at the two they appear that they'll work.

Image appears courtesy of, where I bought the part from for 1/3 the price of O'Reilly and 1/2 the price of AutoZone.

New manifold is installed in place. Pretty tight fit around the A.I.R. hoses but they were curved this way on the Olds full size lineup too, so no reason why they couldn't use this hose. Unless for some odd reason it interferes with the tensioning of the A.I.R. pump, which as best I can tell is uniquely mounted on the Cadillac version of the Olds 307 compared to the Oldsmobile, Buick, and Pontiac versions. And I'll bet if for some reason I need to remove the compressor mounting hardware it will be more inconvenient than before.

Frustration... it's 3 inches too short. It isn't a drop-in fit.

That's all right, a few direct and calculated bends on both ends allows it to mate up with condenser fitting. New lubricated o-rings were used.

Everything fits. Just barely. It's more convoluted than the original manifold, but since that isn't reproduced, this is what we do. Olds used it for years on their cars.

Let the vacuuming begin!

After pumping down for 90 minutes, closing the gauge manifold off, and turning the pump off, it is holding steadily at around -28inHg, which is pretty good. Time will tell if it remains there.

Now begins the fun part of waiting overnight (or 2-3 days to see if the leak is playing the slow burn game) before we can charge it and get it running again.

Return to 1989 Cadillac Brougham

Last updated September 20th, 2018