[N*Caddy]

I spent pretty much most of today replacing the ELC compressor. YEAH almost a whole day!
My exhaust solenoid valve coil went bust and it was shorting out so the CVRSS disabled the ELC since almost 1 month ago (well I was away so I could not address the issue earlier).

I bough (cheap) this brand new ELC compressor (pictured above) as it was almost impossible to find just the compressor head (where the exhaust solenoid is). The trick was, the compressor was for a mystery GM car, so there are some differences. First is the most obvious, is bare metal not painted black so I am sure it will rust like crazy, this is why is only a interim solution. Then the intake port is on the bottom of the compressor head and is not a nipple thing where you can put the intake hose. So this will pull dirt, dust and moisture in no time (the intake originally is away from dirt). Every single connector (except the ground) is different. Since the compressor came with no harness I had to modify the original compressor harness to work with the new compressor (no fun at all). The mounting brackets on the new compressor were in the right position but 90* turned so I had to use the original (rusty) brackets. The muffler has only one port while the original muffler has two output ports so I had to swap the mufflers too. Other than that 100% compatible, and as I saw little better build inside. The compressor rod is made of metal not plastic as the original. But yet since is not quite the original compressor it is in there until I find a brand new OEM for the right price.
Now replacing the compressor, I would like to see the designer and have a few words with him/her. They could not find a harder less accessible place for it, right above the rear subframe. The FSM says to release the mounting bracket and pull the compressor, bracket and all out. How they do that without lowering the subframe I don’t know but after literally 1 h of twisting pulling and wiggling I was unable to pull it out (either way I was turning it). Anyway in the end I removed the compressor off the bracket (don’t ask me how) and then I was able after another half-hour or so to get the compressor out (first the bracket then the compressor).
To insert the new compressor, well I was just unable, I ended up removing the muffler, removing the muffler bracket and finally got it in. Then some how (took me 2 hours) I managed to mount the muffler and the bracket turning the compressor every position possible and using all the extensions (various lengths) I had it all assembled while all the dirt was falling on my face, busted knuckles and all that fun.
I really believe is easier to drop the whole rear subframe to do the job. Even the 3 mounting screws for the compressor bracket are going on top of the subframe so you better ask a blind person to do the job, is the Braille method (especially the inner screw).
I am really, really, really, not looking forward to replace the compressor again when I find the one originally intended for the car, and I got lucky, could have been worst if the screws were rusted or snapped on me, very difficult to access but none put a fight. I have in my hair 2 pounds of dirt, fingers I can barely type, is just a horrible job.
At least the best part: the ELC works again, I did the sit in the trunk test (with 2 other friends) and is WORKING!

I would like to hear from somebody else who did this job, was it just me or is really difficult.

 

[mhamilton]

You are not kidding... I just did that job last month. First went to the pull-a-part which usually has dozens of Cadillacs (literally falling over them). This time, maybe 10. Found *one* '98+ Seville and got the pump from that, thought it would be better from a newer model that had it protected in the enclosure. Got that home, found the pump worked but the vent solenoid winding was open So had to go back for an exchange, this time I found a '97 STS that was the only other car with the pump still in it. Luckily, I got that one and tested before leaving. Must have been a low mileage car, because this pump is silent! (also a NC car, no rust at all)

Anyway, getting it out of the STS was like you said. I ended up removing the pump from the bracket and got it out in 2 pieces. Not such a big deal.

On the other hand, getting it in and out of my Eldo... jeeze was that a nightmare! You'd think it would be identical to the Seville, but no. There's just a 1/8" difference that would not allow the old pump to come past the spare tire well even with the right subframe bolt loosened.

What ended up working was removing the bracket, and removing the dryer. Then assembling it all again over the axle. Also took the time to replace the little o-rings in the connector (and the dryer, of course), so at least those should be leak free.

The '98+ Seville/Deville models are nicer with the pump in the fender well, but even those are a PIA with the muffler in the way. And I don't think all that exhaust heat does it any good either...

 

[mhamilton]

BTW, I saw that same level compressor on eBay last month, almost bought it myself! But I noticed that pressure port on top of the head and figured it would never fit under the trunk floor. Looks like that is from a model where the pump was under the hood with plenty of access. Glad you were able to make it work.

 

[N*Caddy]

Oh I had to go back and forth with the seller for a while, he was not willing to ship to Canada. I mean we were literally in driving distance but no shipping to Canada! Eventually he got soft when I offered the buy now price with no argument. That service port on the compressor head cover is not a issue, the problem with this is the intake port. On the Seville/Eldorado is down on the motor case, but on this one is a rectangular slot in the bottom of the compressor head (you can see it in the Seville/Eldorado compressor too but is plugged from casting). Inside the compressor head is a two stage filter. The first part (close to the port) is something that looks like steel wool, then past that (upstream in the air flow) is a sponge thing.
Also the port (vent) for the exhaust solenoid is plugged from casting. Looks like the exhaust does a reverse flow trough the filters and out on the intake port.
I also think I know why my exhaust solenoid went bad (at least is my theory).
The hoses from the filter to the intake port and exhaust valve are made of s***, the small section of hose from that "T" to the exhaust port was cracked and the exhaust port was free to air. The exhaust solenoid is a intake port too (when the compressor is on) so it got unfiltered air in the compressor head.
So replace your hoses until is not too late. That rubber was tacky and mushy, kind of like a low quality rubber hose immersed in gasoline for few weeks.
This new compressor makes no vibration at all, is difficult to tell when is on, all you hear is a distant buzz, well that until will rust, I am sure will not be in there more than 1 year.
I think I will look for a new compressor for Buick Lucerne, Cadillac Deville and similar as the one for our cars probably are long time discontinued. I may run into a different harness connector though.

The new Seville, Deville and all Buicks with ELC have the compressor in a super easy accessible place (behind the fender), that is a pleasure to work on, but nooooo not on ours.