As of October 1st, 2022 the CLC has reduced the annual e-membership dues to $25. Non-CLC members in the forums, time to join and experience all the other benefits? See post in the General Discussion forum for a link to the Join page

Main Menu

1966 Series 60 Fleetwood: Automatic Level Control Testing

Started by 69Deville, January 27, 2023, 02:14:33 PM

Previous topic - Next topic


I am looking to test my ALC on my 1966 Series 60 and am having trouble knowing where to start.

Here is a brief description of the system as it stands now.

-Compressor and leveling device (rear of car) are in place
-Compressor tank has a small dent (looks like someone started to jack the car up on the tank instead of the frame). The front of the compressor looks good, only the tank has a small dent
-Vacuum lines to the compressor were disconnected when I bought the car
-The air lines from the leveling device to the shocks have been cut and regular shocks have been installed

I'm not sure where to start, but I'd like to replace the shocks and hopefully can reinstall the system.
1969 Cadillac Deville Convertible
1966 Cadillac Series 60 Fleetwood
1996 Cadillac Fleetwood Brougham-sold :(

Chuck Swanson

66 Shop Manual, section 4 has all the detailed info to help.

CLC Lifetime
AACA Lifetime
Like 65-66 Club:
66 DeVille Convertible-CLC Sr Wreath, (AACA 1st Jr 2021, Senior 2022, 1st GN 2022), Audrain Concours '22 3rd in Class.
66 Sedan DeVille hdtp
66 Calais pillar sedan
66 Series 75 9-pass limo
65 Eldorado (vert w/bucket seats)
65 Fleetwood
07 DTS w/ Performance pkg.
67 Chevy II Nova (AACA Sr GN 2018)
69 Dodge Coronet R/T

James Landi

The "wear parts" to rebuild those vacuum actuated level control compressors no longer exist, that's why on your car, someone disconnected all of the lines.  The one important vacuum line that goes to the engine mainifold needs to be blocked off! (Likely the previous owner did that)...  There are several work-a-rounds to get your rear end appropriately situated (pun intended).  Some of us enjoy having control over the height, and I, for one, like to raise mine just a little above the "normal height," for a "firmer ride" that tends to keep the car from being too "floaty."  You can purchase "helper" springs for the rear, you can install air shocks in the rear that inflate from a standard schrader (aka tire) valve,or you can shop for rear springs that compensate for the lack of an operating system.  Or you can design a system that actuates a 12 volt inflator pump that you can control from the cabin. THe orignal system was entirely automatic and very lovely, but, as I mentioned above, parts that wear out are no longer available.   Hope this helps you,  James 


Could I install air shocks in the rear now and then when (if) I get the ALC working, connect them to the valve in the back. I took the compressor off and its holding vacuum.

I have the vacuum ports plugged on the lid of the air cleaner and at the PCV as well.
1969 Cadillac Deville Convertible
1966 Cadillac Series 60 Fleetwood
1996 Cadillac Fleetwood Brougham-sold :(

James Landi

Mr. Mirrione,

When you connect the pump to a stong vacuum source, you SHOULD hear a rapid clicking sound, and feel the pump compressing air. If you don't hear and feel the pump operating with vacuum applied, the pump mechanism is stuck--- likely worn out after decades of use, and jammed.  Chuck suggested that you study section 4 of the service manual. I concur    Hope this helps,  James