davedog Posted January 18, 2006 Report Share Posted January 18, 2006 I think my air ride is starting to fail, the more time goes on the less it takes to bring my caddy's rear to the ground. A couple days ago i put the groceries in the trunk, and by the time I got home the rear of the car was VERY low. When ever I have people in the back seats on trips sinks so low it feels like I have no shocks at all in the rear! Hasn't someone talked about some regular struts you can install instead of the expensive task of replacing the OEM ones? Linky? Is this a job I can do my self? Thanks guys!!! -dave Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
jackc Posted January 18, 2006 Report Share Posted January 18, 2006 I think my air ride is starting to fail, the more time goes on the less it takes to bring my caddy's rear to the ground. A couple days ago i put the groceries in the trunk, and by the time I got home the rear of the car was VERY low. When ever I have people in the back seats on trips sinks so low it feels like I have no shocks at all in the rear! Hasn't someone talked about some regular struts you can install instead of the expensive task of replacing the OEM ones? Linky? Is this a job I can do my self? Thanks guys!!! -dave Dave - your car should have air shocks on the back of it rather than struts. Sounds like you're losing air and your compressor either isn't kicking in to reinflate, or can't keep up with the leak. Check the air lines for breaks or leaks. As I recall, there are some o-rings at the various connection points. You also may want to check if your compressor is working correctly. Your FSM should lay out the routine to check. The air-side of those shocks is tough, and likely to be that last place it will fail. After-market passive shocks are available if it comes down to that. Yes - you can do it yourself. But check things out first. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 18, 2006 Report Share Posted January 18, 2006 Oh yes, you buy standard Air Shocks, you will get a code however but your rear will be up.... However, that said, but sure your shocks are leaking and its not the tubing, my tubing was worn very badly where it was rubbing any metal... Check the tubing first. I just checked Arnottindustries and they don't show a replacement for your year they begin in 1993.. Boston Suspension shows Front Struts for your year but they don't appear to show rear struts, you might call them....for 1993 they are $275 I checked Strut Masters and you need to provide your VIN number to them, if they have the rear they will cost $279 Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
KHE Posted January 18, 2006 Report Share Posted January 18, 2006 Check the air lines for leaks... the air shocks in the rear usually last the life of the vehicle. If you sit on the rear bumper, does the compressor come on? If not, the fuse may be blown or the compressor relay may be bad. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
davedog Posted January 18, 2006 Author Report Share Posted January 18, 2006 thanks for the fast responces. the compressor is working, i hear it come on when I start the car, and if I have nothing in the trunk it levels back out and shuts off like it should however, it there is a load it runs for a while, then stops (to protect it self I think), so there must be a leak in the struts or lines. I will check the lines, but I was under the impression that when this happens it was the struts. I got a quote from my mechanic to go with the standard type shocks, he said ~625 with labor, ~75 more if they start working on it and it needs alignment. Seems fair....I think. Tips on testing the lines for leaks? Just jack it up and spay water on everything.....but wait, wouldn't it need to be down with a load on it? Hmmm.....suggestions? Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 18, 2006 Report Share Posted January 18, 2006 If standard struts are about $300, $675 is way too much if you ask me... If you can get the rear up on jack stands (under the control arms to keep the cars weight on the shocks) great, otherwise you will need to do this on the ground with good lights. Chock the wheels front and back. Put a good amount of dish soap in a spray bottle and soak the rubber shock ballasts heavily and lines where they connect and lines. Start the car and load trunk with sand bags and look for bubbles and continue spraying while looking and listening for bubbles. Check the connections at the shocks, we had a member recently with a bad connection/o-ring at that location. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
davedog Posted January 18, 2006 Author Report Share Posted January 18, 2006 If standard struts are about $300, $675 is way too much if you ask me... If you can get the rear up on jack stands (under the control arms to keep the cars weight on the shocks) great, otherwise you will need to do this on the ground with good lights. Chock the wheels front and back. Put a good amount of dish soap in a spray bottle and soak the rubber shock ballasts heavily and lines where they connect and lines. Start the car and load trunk with sand bags and look for bubbles and continue spraying while looking and listening for bubbles. Check the connections at the shocks, we had a member recently with a bad connection/o-ring at that location. OH! $300 a pair, I thought you meant $300 each! oops! LOL. Yeah he said parts would be ~489 and labor ~$137.50....so i dunno, he's always done me right before, and been honest, but yeah now it sounds high. I will check the lines tonight, thanks so much for all the info. Are the lines easy to spot, do I have to remove anything to get to them? Thanks again!!! -dave Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
jackc Posted January 18, 2006 Report Share Posted January 18, 2006 There should also be an exhaust solenoid in the compressor - could there be an internal leak there causing the system to bleed down? Might be something to check out..... Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 18, 2006 Report Share Posted January 18, 2006 Yep, $300 a pair, check: http://www.arnottindustries.com http://www.bostonsuspension.com http://www.strutmasters.com You should not have to remove anything.. The compressor has a reed valve in it if I recall and and exhaust solenoid as jackc noted. I had to replace the compressor head in my 91. I would look at the rubber ballasts and lines, look at the rubber ballasts closely, my 96 had many cracks in them.. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
davedog Posted January 19, 2006 Author Report Share Posted January 19, 2006 WHAT GIVES!!!???!!! -Backed caddy onto ramps to provide hight to get under car, and still put load on air ride system. - Loaded up caddy with various extra computer equipment, heavy 19in CRT monitor, two older full tower computers, I eve sat in the tunk on top of this at one point (another ~150 lbs) it never started sinking....ever! Ran car for a while, compressor kicked on for a few seconds (a sort of power on self test accoring to the manual) - car still remained at normal hight! What gives. Surley that was at least as heavy as the oad of grocies I had the other night. No leaking noises, no chnage in hieght- NOTHING! Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
adallak Posted January 19, 2006 Report Share Posted January 19, 2006 WHAT GIVES!!!???!!! -Backed caddy onto ramps to provide hight to get under car, and still put load on air ride system. - Loaded up caddy with various extra computer equipment, heavy 19in CRT monitor, two older full tower computers, I eve sat in the tunk on top of this at one point (another ~150 lbs) it never started sinking....ever! Ran car for a while, compressor kicked on for a few seconds (a sort of power on self test accoring to the manual) - car still remained at normal hight! What gives. Surley that was at least as heavy as the oad of grocies I had the other night. No leaking noises, no chnage in hieght- NOTHING! You lifted the rear of the car and the system thought it was fine! Lower the car, put something in the trunk. Turn the ignition ON (do not start). The air compressor should kick off and run for some 20-45 seconds. If there is nothing in the trunk it kicks off for a few seconds when you turn the ignition ON. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 19, 2006 Report Share Posted January 19, 2006 Did you squeeze the rubber ballasts on the struts to see if they are hard with air? Wow backing up on ramps is quite a task! Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
brmurph Posted January 19, 2006 Report Share Posted January 19, 2006 When I had this problem it turned out to be the compressor leaking (I think it was the exaust solenoid like previously mentioned). What happend on mine was very difficult to diagnois because like your problem it would pump up just fine with a load, dealer added 500lbs and said it pumped up just fine no problems, it would then start to leak out slowly over time. What I found out is that at some point (I think time and speed related) the computer no longer makes ajustments so if the air starts to leak out over a period of time (in my case hours on the expressway) the rear end would ride low until I restarted the car, then it would pump up just fine. If you want to verify that you have a leak I would suggest adding about a 300lbs load (I used sand bags, cheap and easy to measure weight) to the trunk over night. Add the extra load and turn the key on to allow the rear to pump up to normal height and measure the height of the rear. Turn the key off and let it sit over night and measure again in the morning, if it is down more then a 1/4 of an inch then I would say you have a leak large enough to cause problems. This is what I had to do after the dealer replaced the rear shocks ($2300.00 and said it was all fixed, it wasn't). If I remember correctly it would be down about 1.5 inches by morning. I actually measured it by the hour, you could see it drop every hour. Once the compressor was replaced it would hold the load overnight. One last thing, I had to do this several nights because some nights it was just fine, other nights it would be real low by morning. I think the problem was that sometimes the exaust solenoid would leak and some times it didn't, that would explain why your problems are intermittent. Good luck. Link to comment Share on other sites More sharing options...
davedog Posted January 19, 2006 Author Report Share Posted January 19, 2006 WHAT GIVES!!!???!!! -Backed caddy onto ramps to provide hight to get under car, and still put load on air ride system. - Loaded up caddy with various extra computer equipment, heavy 19in CRT monitor, two older full tower computers, I eve sat in the tunk on top of this at one point (another ~150 lbs) it never started sinking....ever! Ran car for a while, compressor kicked on for a few seconds (a sort of power on self test accoring to the manual) - car still remained at normal hight! What gives. Surley that was at least as heavy as the oad of grocies I had the other night. No leaking noises, no chnage in hieght- NOTHING! You lifted the rear of the car and the system thought it was fine! Lower the car, put something in the trunk. Turn the ignition ON (do not start). The air compressor should kick off and run for some 20-45 seconds. If there is nothing in the trunk it kicks off for a few seconds when you turn the ignition ON. i din't lift up the car, I bcaked it onto ramps, wouldn;t that provide the same amount of pressure on the system? And yes, the comprssor kicks on. When I had this problem it turned out to be the compressor leaking (I think it was the exaust solenoid like previously mentioned). What happend on mine was very difficult to diagnois because like your problem it would pump up just fine with a load, dealer added 500lbs and said it pumped up just fine no problems, it would then start to leak out slowly over time. What I found out is that at some point (I think time and speed related) the computer no longer makes ajustments so if the air starts to leak out over a period of time (in my case hours on the expressway) the rear end would ride low until I restarted the car, then it would pump up just fine. If you want to verify that you have a leak I would suggest adding about a 300lbs load (I used sand bags, cheap and easy to measure weight) to the trunk over night. Add the extra load and turn the key on to allow the rear to pump up to normal height and measure the height of the rear. Turn the key off and let it sit over night and measure again in the morning, if it is down more then a 1/4 of an inch then I would say you have a leak large enough to cause problems. This is what I had to do after the dealer replaced the rear shocks ($2300.00 and said it was all fixed, it wasn't). If I remember correctly it would be down about 1.5 inches by morning. I actually measured it by the hour, you could see it drop every hour. Once the compressor was replaced it would hold the load overnight. One last thing, I had to do this several nights because some nights it was just fine, other nights it would be real low by morning. I think the problem was that sometimes the exaust solenoid would leak and some times it didn't, that would explain why your problems are intermittent. Good luck. Great info - this sounds to be my exact problem, since this only occurs (now that I think about it) after driving around for a while with a load. So you replace the comprssor to replace the colenoid? What kind of cost are we talking about? After what I went through last night, this has GOTTA be the problem I will talk to my mechanic today and see what he says. Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
jackc Posted January 19, 2006 Report Share Posted January 19, 2006 BodybyFisher mentioned replacing only the compressor head as the fix for his. A flakey reed valve is sounding like a definite possibility. Its part of the head, isn't it? Link to comment Share on other sites More sharing options...
brmurph Posted January 19, 2006 Report Share Posted January 19, 2006 Luckily when I had my problem the car was still under warranty (third party extended warranty at that, and yes they did pick up the tab for both shocks and compressor). My understanding is that you can replace just the exaust solenoid as you can get that piece separately, since my car was under warranty the dealer choice to replace the whole compressor (who was I to complain :-). Seems to me the cost was about $550.00 for the compressor replacement (done by the dealer, parts and labor). I think gmpartsdirect.com had the parts for sale seperatly if you want to check prices. Also I don't know for a fact that the exaust solenoid was the problem, I just know that after the compressor replacement (which comes with the exaust solenoid) the problem was solved. Link to comment Share on other sites More sharing options...
JasonA Posted January 19, 2006 Report Share Posted January 19, 2006 If you backed it up on ramps, the center of gravity of the car was different, and much of the weight was shifted forward towards the front, off the rear suspension. I would not recommend going with non air shocks as replacements. The spring rate is specified assuming that operational air shocks are installed as well to supplement during high load situations. Without air shocks, I feel you'll be in the same situation you're in now -- put a lot of people in there and the back end will sit down. Places like Boston make passive air shocks that can be installed that will work with both your suspension system computer AND the air compressor...if the shocks are indeed your problem. Perhaps it is another component in the system. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 19, 2006 Report Share Posted January 19, 2006 Jason is correct, you have to use air shocks no question about it... EVEN if you manually fill them and eliminate the compressor altogether like we did in the old days. My dad had a 65 Caddy with a vacuum air shock pump for the rear air shocks that was no longer functional, we just put a T into the line and filled them directly to the desired level. Boston Suspensions sells a kit to eliminate the level control altogether but you must use air shocks or she will sit low Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
KHE Posted January 19, 2006 Report Share Posted January 19, 2006 You do not need to buy the entire compressor assembly. Locate the compressor and use a soapy water solution to determine if the leak is in the head assembly. The head assembly with exhaust valve can be purchased separately. You will need to use RTV to seal the new head and bolts per the service manual. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
davedog Posted January 19, 2006 Author Report Share Posted January 19, 2006 so i guess what it boils down to is my next step is jacking the car back up, pulling the compressor, and running a pressure test on it. I wonder if the head can be found at a local auto zone? The compressor seems kind of hard to get to, I couldn't really get a good look at it - seems like I might need to moke some of the exaust components out of the way??? Thanks again for all this info. Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 19, 2006 Report Share Posted January 19, 2006 Its not easy to get at (there are three or four bolts that hold it to the cross member that run through rubber grommets), it will be easier to pull the wheel off, be careful to use safety stands and chocks... Here is a typical photo (from 91 manual) of the compressor, tubing and struts, I had mine out and replaced the head as I mentioned, Mike If you send me an email I will send you all of my level control scans Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 19, 2006 Report Share Posted January 19, 2006 BodybyFisher mentioned replacing only the compressor head as the fix for his. A flakey reed valve is sounding like a definite possibility. Its part of the head, isn't it? Yes, I do believe it is, as a matter of fact you can see the compressor piston when the head is off, so yes the reed valve is part of the head... my compressor when bad shortly after I went through deep water and when I removed my compressor head the reed valve was rusty... There is also a dryer on the head to keep moisture out of the head.. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
davedog Posted January 19, 2006 Author Report Share Posted January 19, 2006 Its not easy to get at (there are three or four bolts that hold it to the cross member that run through rubber grommets), it will be easier to pull the wheel off, be careful to use safety stands and chocks... Here is a typical photo (from 91 manual) of the compressor, tubing and struts, I had mine out and replaced the head as I mentioned, Mike If you send me an email I will send you all of my level control scans Thanks for the offer mike (you are always so helpful with your scans). I do have the GM 1992 eldorado/seville manual though. If it were only as easy to get to as the picture looks! LOL. So taking off the left wheel (if I'm standing in back of the car) would give me better access to the compressor? Where did you get a replacement head for yours? By the stories you guys are telling me it almost has to be in the compressor/head somewhere - otherwise it would leak non-stop it seems. I'm for sure doing a little more investigation before I shell out $600-$700 to bypass it all (or $300 to do it myself). You guys are awesome! Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 19, 2006 Report Share Posted January 19, 2006 Its the Right Rear, or passenger rear wheel or side of the car. I bought my compressor head from the dealer, you should try rockauto or gmotors. I checked Rockauto and they didnt list it, but you should call. Its an easy job, the hardest part is getting it in and out.. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
KHE Posted January 19, 2006 Report Share Posted January 19, 2006 You can fix the problem for a LOT less money than bypassing the system and you will retain the automatic load leveling feature. You just need to do some diagnostic work. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
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