: Rear Shock Absorber



AllenPacla
03-29-05, 11:51 PM
I am thinking that my rear shock absorber might be needing a replacement because everytime i am loaded heavy, it takes so long for the self leveling device to actually do the levelling. Or is this related to another problem? And if in case it's the rear shock absorber, I believe that Monroe is the brand that fits the Catera. Should I be looking for a specific model? How about the self leveling feature of the rear suspension, how is it going to be affected by replacing the shock absorbers? And should I also be considering replacing the spring coils? Thanks for any advice.

Vesicant
03-30-05, 12:22 AM
Monroe does make a replacement load leveling shock (Called the Max Air), but im still determing if that will work- the "shock finder" on their website shows it as needing a seperate kit to attach it, so this may be issue (if thats the problem you're having). Notes: Only the rear shocks on the catera are airbag/load leveling; the front are regular non controlled struts.

IN the meantime heres a list of what could be wrong:

1. Compressor is worn out or malfunctioning
2. The controller is malfunctioning
3. You may not loading it enough for it to really see much to improve ride height.
4. A leak in the system

Technically the system should respond within 30 seconds of there being an extreme weight/level change. On start up it inflates the system without the use of the level light- so the only way to tell externally is hearing the compressor. Front passenger side and if i recall its in the bumper area; you'll know the sound if you listen hard enough. Keeping in mind that ontop of this on start up the ABS system is also making noises doing prechecks.

AllenPacla
03-30-05, 12:21 PM
If you are saying that the Leveling light should not be lighting up during start up, then why is mine doing it all the time. It will light up for maybe a second or two and then disappear, just like the rest of those warning lights. They will all light up and then disappear. But when suddenly I load the car with let's say 5 people and then some more in the trunk, there was like 3 occassions that it just kept lit up, I mean the "Leveling" notice in the dashboard. So, I was thinking that it could be the shock absorbers, but since you mentioned about compressors and all these stuff, I am leaning towards blaming any of those you mentioned than the shock absorbers. By the way, how does the controller determines the level, is it a preset height or pressure? Because the bottom line is when loaded heavy, the car can't get it to the preset value so it just keeps on leveling the car. Could be an air leak in between the compressor and the shocks:hmm: . Thanks Jeff. I need to know more about this before i bring it to a mechanic so I won't get ripped off. Or perhaps if it's something I can fix myself then much better.

AllenPacla
03-30-05, 12:25 PM
By the way, is that compressor exposed? How about the tubings that lead to the air shocks, are they easily accessed as well. Because there could just be leaks at connections, a clamp there or somewhere.

Vesicant
03-30-05, 08:27 PM
If you are saying that the Leveling light should not be lighting up during start up, then why is mine doing it all the time. It will light up for maybe a second or two and then disappear, just like the rest of those warning lights. They will all light up and then disappear. But when suddenly I load the car with let's say 5 people and then some more in the trunk, there was like 3 occassions that it just kept lit up, I mean the "Leveling" notice in the dashboard. So, I was thinking that it could be the shock absorbers, but since you mentioned about compressors and all these stuff, I am leaning towards blaming any of those you mentioned than the shock absorbers. By the way, how does the controller determines the level, is it a preset height or pressure? Because the bottom line is when loaded heavy, the car can't get it to the preset value so it just keeps on leveling the car. Could be an air leak in between the compressor and the shocks:hmm: . Thanks Jeff. I need to know more about this before i bring it to a mechanic so I won't get ripped off. Or perhaps if it's something I can fix myself then much better.

The leveling light comming on during your trip doesnt sound that abnormal... especially if it was that loaded. The light comming on during the IP check on statup - normal. Basically theres a magnetic sensor on the frame and the suspension- it runs back to the controller relay for the pump. If it rises above the sensor then it pumps until its level again. If it goes too low (vehicle is rising once weight is off) then it releases air and pumps until its level again with the magnetic sensor. The air-lines run back and to each shock, you can see it on this photo i took; the line runs to the side of the shock and the bag is on the bottom half. This can be something you can fix yourself with the help of a shop manual.

AllenPacla
03-30-05, 09:28 PM
So are you suggesting that there may be a leak somewhere along the lines? Because, the reason why it just keep on leveling with heavy load is because it can't get enough height as you suggested which means that air pressure is not enough to bring the shocks to a desired height. I guess I'll have to look for leaks, or could it be a weak compressor not generating enough pressure to get the shocks to rise. But I'm thinking, if it's a leak, then why is it that even if the load is like say 4 people or maybe 5 but without nothing in the compartment, why is it not happening? I mean, the car would just level normally and i won't see that light saying the car is leveling. If there is a leak, then it would continually leak air and once in a while, I will have to see that leveling notice. But since i don't see it, it means that the initial leveling that the car did is holding up. Unless the compressor is continually producing air, which to me if happening, should get that leveling notice lighted up in the dash board. I am not sure if my analysis is right because i am not aware of the actual mechanics of this leveling system in cars. And why is it that if in case the passengers get out of the car, i don't remember seeing the leveling indicator light goes up again. It should light up again right, since the air will be too much after the passengers alight so the leveling system must release some air to get the car levelled again. Oh boy, this sounds like something we have to understand better to finally figure out. :confused:

stevehogan
03-30-05, 10:56 PM
Here's EVERYTHING you ever wanted to know (and some stuff you probably don't care if you know :) ) about the Automatic Leveling Control

AllenPacla
03-31-05, 01:28 PM
Thanks about that Steve. Reading through it, it just confirms that the leveling system failed to level the car when i got it filled with 5 people with things in the trunk, but i'm just wondering, the 5 people i go it were not big. It says that when an extreme amount of weight is loaded that may cause problem the leveling light illuminates but not during normal raising and lowering. So, it means that the car lowered beyond what the car deems to be normal and then since the light stayed illuminated, it means that it fails to level the car no matter how much the compressor pumped air into the system. Correct me if my analysis is wrong, could it be the springs wearing that it folds too easily even if the load is not that much really or the air max leaking air after it is initially inflated. Because, it also says that the system is designed to not pump air continously in cases of severe leak in the system. And after each compressor cycle, the shocks should seal off so that air won't escape. It's a little confusing though, because there is no telling wether or not the car keeps on doing some leveling when i am alone in the car of when I have like three passenger because the leveling light does not illuminate during these normal operations. Anyway, I don't see it happen unless i have heavy load, should I be worrying that not finding the root of the problem now would eventually cause me some major headache in the future? And why is it that springs are just so difficult to find for the Catera, I mean aftermarket ones that doesn't lower the car. Thanks guys

stevehogan
03-31-05, 01:59 PM
It might be that the compressor is getting worn or that you indeed have a small leak in one of the control valve.

There is a complete checkout procedure in the Service Manuals. The preliminary test involves loading the trunk with a 300 pound load and seing if the car returns to its original trim height after the compressor stops. (It should run no longer than 3 MINUTES - it will take 25 seconds for the compressor to initially respond.). Then removing the weight and seeing if the car returns to the original trim height after 5 MINUTES. If it passes those two tests, the next step in the test program is to have a martini and stop worrying about it. :D

AllenPacla
03-31-05, 03:57 PM
Well, let me get that Martini ready then before i do the testing because in case the car fails the test, i will get drunk first before deciding to fix it. Thanks for that tip, i'll certainly do that, I guess i'll have to hire one of those guys who stand around the corner of our block looking for part time jobs, I just hope they won't charge me that much for a 15 minute experiment. Hey by the way, I have finally proven that HID would perform well during rainy condition. I just installed an HID foglight replacing the one in the Catera and complementing it with the Extreme White lights by PIAA as my headlight, the result is just awsome. And during rain, I still get a good illumination from the HID foglight but of course, the headlight becomes invisible. This puts me in a dilemma, my fingers are now itching to get my headlights converted into HID as well, I'm thinking, with the foglights(HID) and a set of HID headlight, i'll be blinding everyone in front of me( just kidding). I mean properly aimed, the performance is just unmatchable by any type halogen bulb combination.

Vesicant
03-31-05, 04:45 PM
So are you suggesting that there may be a leak somewhere along the lines?

Not exactly... That sentince " This can be something you can fix yourself with the help of a shop manual." should have been reworded to make it mean that whatever's wrong should be easy to fix with a simple shop manual. Sorry for the confusion in this all Lol.

stevehogan
03-31-05, 04:50 PM
FOFL :eyebrow:

AllenPacla
03-31-05, 11:23 PM
Maybe you're the one having the Martini, what do you say Steve?