Auto-level Compressor Rebuild / 1976 Fleetwood

[35433]

I have a 1976 Fleetwood with an air compressor that is not not working. It is receiving vacuum and is making a clicking noise when the engine is running, but is not retaining pressure. I see that the air bladder many times goes bad. Does anyone know someone who rebuilds these units or have any ideas how to get it working? Thanks much!

["Cadillac Kid" Greg Surfas 15364]

caddy Daddy shows one for up to 1970 but perhaps they have a source for rebuilding. At $500 it actually is a bargain
Greg surfas

[35433]

Thanks Greg. I see that compressor on Caddy Daddy. It is a different one from what mine is, but that's a good idea to see if they can rebuild mine.
-Dan

[Big Fins]

Before you condemn the compressor, if you have it out, look really good at the bottom of the canister. Over the years, moisture builds up especially if you live in a humid area. The canister rusts from the inside out.

Take the canister off the pump, if this is the case and locate a shop to either braze up the hole or if the rusted area is too big, braze a patch to the lower end.

Many times the compressor works correctly, but there is a break in the line feeding the rear and/or the leveling valve is bad and hanging open. Can you inflate the system through the charging port at the top of the pump? It looks like a tire valve stem.

[The Tassie Devil(le)]

I know that the rust issue is relevant, but in this case, I haven't seen much worse.   Funny thing was that the actual pump was all there and still operational when the vacuum line was connected.   It came out of a rusted-out '71 that I purchased for parts, and going by the discolouration of the tank, the car must have sat for a long time, filled with leaves and dirt.

Look for a punctured pressure hose, as well as the leaking inflation bag.

Bruce.

[James Landi]

Moisture condenses on the high "compression" end, which also serves as a check valve, so once that pump end corrodes the tiny rubber valve seat,that's the end of the pump. It will click but it won't hold pressure.  Rebuilt a couple of these way back in the 1970's when rebuild kits were still available-- the kit consisted of two fiber compression rings, the high pressure check valve---essential "wear parts." However, in my limited experience the soft metal end that included that check valve were usually badly corroded in the junked Cadillacs, so a couple of my rebuilds would click away, but not hold pressure.  The second generation electric level ride pump was far more durable, and it included an electronic timer that shut off the pump if there were a leak, thus protecting the pump from clicking its life away.  If you still can find a first generation vacuum actuated pump  that works, consider yourself very fortunate.  James

[Highwayman68]

Pull the output hose off of the compressor.

Start the car and hold a balloon or rubber glove over the output connector and watch to see if the balloon inflates at all. This will tell you if the compressor is working properly.

If it does then seal the balloon to the connector, once the balloon is full enough turn off the car and see if the balloon stays inflated. This tells you if the compressor has a leak.

If both of these pass then you have a leak in the system on past the compressor which is a whole different but less costly issue.

See video of me doing this below.


https://i.imgur.com/sqvijTG.mp4

[35433]

Great information, thanks all! I bought a new valve from Dayton Air Suspension so the valve should be fine. I will do the balloon air check. I did pump it up from the stem on the top of the compressor, but it did not hold air. The compressor is extremely clean and still shiny but I will check it out for corrosion as suggested. If it does hold air, I will replace the line to the valve. Thanks again.