View Full Version : My hearse has an air exchanger

Wesley Hord
04-29-2015, 02:16 PM
Okay, as stated in the title, my hearse literature states that it has an air exchanger for the rear compartment.

As a Cadillac Fleetwood, my car has a part that I can't find as being a part of a 1992 Fleetwood - an electric vacuum pump, mounted just forward of the front drivers-side tire underneath the car. It connects on one end back to the power brake booster, and on the other end is connected to... nothing. There is a hose, and it is connected to nothing. And I can't find anything it MIGHT connect to!

My car runs fine, brakes fine, etc. The pump has been disconnected until today. It runs, it's noisy as all-get-out, but it doesn't seem to have a function.

So I'm curious if it could be connected to the air exchange system possibly?

Paul Steinberg
04-29-2015, 02:21 PM
That air compressor is for the rear shocks. There is, or was, linkage to connect the rear differential to the body, and when the vehicle was loaded, the linkage would adjust the ride height to a neutral stance. Good chance that the original shocks were removed, and it is also a good chance that someone has removed the original linkages. I have no idea why when the system is rendered inactive by replacing the shocks with a standard shock, the person doing the work almost always removes the linkage assembly. There is no reason to remove it, since it is strictly a mechanical devise that controls the air from compressor to the shocks. If you disconnect the line, and unplug the compressor, the system is rendered inactive.

Wesley Hord
04-29-2015, 02:31 PM
That air compressor is for the rear shocks.... Good chance that the original shocks were removed...

No, I still have rear air shocks, and they work just fine. This has got to be something else.

Kurt Arends
04-29-2015, 07:17 PM
Factory air suspension, or aftermarket air shocks on it currently?

John Royark JR
04-29-2015, 09:05 PM
The air compressor would not be down there, so its not that. The leveling system compressor is near the top of the engine, mounted between the engine and fender well.
I cant remember what the part that I think you are referring to is called, but I remember hearing its part of the emission system, and almost every one Ive seen gets unplugged because of the noise it makes with age. I unplugged the one on my coach over 100,000 miles ago and has no effect on the car. Again, that is if its the same part, tucked just on the inside of the fender right by the inner fender well, and can be easily unplugged from laying on the ground and reaching up. I never looked to see where the lines go.

Wesley Hord
04-29-2015, 09:38 PM
Well, I appreciate the help my friends! But I got someone at cadillacforums.com involved, and they were able to photograph pages from the factory service manual for the fleetwood/deville/60 special line-up. It is a vacuum pump that is used to give the brake booster additional boost. I guess it provides more consistent and powerful vacuum. It was only used on commercial chassis cars. So, I guess now I know!

If any of you drive Cadillacs and need any other information for your vehicles that is specific to the Cadillac part, I highly, HIGHLY recommend that you join cadillacforums.com. It's broken down into classics, modern Caddys, and discontinued cars, with appropriate subforums. A lot of great people there willing to help - just like here!!!

Kurt Arends
04-29-2015, 10:35 PM
Or........ buy the factory service manual and own a quick and easy reference!!