FAQ: Automatic Leveling Control (ALC) Concerns

Your compressor is probably fine, but it will burn out unless you fix this soon. You have an air leak somewhere, could be the shocks, the connectors, or the lines. This makes the rear end sit low, causing the compressor to kick on. How's the ride height in the rear?

The noise you are hearing is more than likely the compressor trying to fill your shocks. If the Air Shock(s) or the plastic tubes are leaking you will burn out the compressor eventually, Although there is a timer in the circuit that shuts the compressor off after so many minutes if the controller hasn't already told it to do so because the height of the car is where it should be.
But that timer is reset every time you turn the key on.

The system is simple once you understand how it works. Do you have the FSM for it.? (Factory Service Manual)

One thing you might want to do is remove the relay that controls the system from under the back seat and save your compressor until you can sort out what the problem is.

I do not have a service manual. But I have alldata at school. I did see a 2 volume shop manual on craigslist, but I didn't manage to jump on it in time.

So the compressor is probably fine? How do I find if it's the shocks themselves or if it's the lines leading to them?

edit: Not sure about the ride height. Not sure what it should be, I don't really have a reference. I know it's really bouncy, prone to coming close to bottoming out at the bottom of hills, and lifting up pretty high while cresting a hill.

honestly though,youre better off just replacing your leaky shocks and surrounding components with monroes . you can adjust the air yourself and never have to worry about expensive leaky oem stuff again. and monroes dont cost a whole lot. do a search here to get part#s and related repair info.
and when you do the swap,remove the compressor and make an attractive paper weight out of it. when your friends ask you what it is,tell them its a flux capacitor .

robotennis61 wrote:

honestly though,youre better off just replacing your leaky shocks and surrounding components with monroes . you can adjust the air yourself and never have to worry about expensive leaky oem stuff again. and monroes dont cost a whole lot. do a search here to get part#s and related repair info.
and when you do the swap,remove the compressor and make an attractive paper weight out of it. when your friends ask you what it is,tell them its a flux capacitor .

I understand that the MA-822s are 'direct fit' replacement and work with the factory lines and compressor...

they are, and if you get the monroe AK29 kit too, you can bypass your compressor.

The ride is 100X better with the bypass. The wife has the air ride, I have the bypass kit. Day and night difference.

yap. i love my bilsteins .

You said you have AllData, then look up the Description and Operation of the Level Ride system and all will become clear to you.

You have the manual, if you have Alldata, so you no longer need to ask specific technical questions, unless the data is unclear.

Read, interprate, and then teach young grasshopper.

Ok Guys, I saw a small thread on this subject earlier, but have not seen anything in detail.
Here is my question.
I have a almost brand new commpressor pump from my 95 riv, bought it from rock auto 8 months ago. I now have a 97 riv. I would like to replace the commpressor in the 97 with the new one from my 95 riv. They are different. wiring mostly I think. I have not really taken off the commpressor from the 97 yet to compare. I think the commpressor is not filling my rear shocks as well as it should plus its orginal, and has 144,000 miles on it, sooo would love to put my brand new compressor on.

Has anyone already done this??? I am thinking it can be done, just would like to know if someone has already tried this and what they needed to do for the conversion??
Thanks.....Mike.

Yes, the compressor is different, but I can't tell you why. Looking at the schematics for both years, the wiring is identical. The plug might be different between the 2, but I don't know. For some reason I have no connector end view for that plug.

The compressors use the same dryer, exact same. and the clyinder heads are both the same.
plug on end of cable is different. frame on which both compressors sit on is different. I am thinking if the wiring is the same like you said.....then I still might be able to convert the 95 pump to work in the 97.

I tried to search but didn't find what I am looking for. I got the eibach lowering springs for the car and the front is lower than the rear. I am wondering if disabling the automatic level control will lower the rear. Will this have any ill effects?

If you disable the leveling control, it's a good idea to swap out the shocks to a standard hydraulic damper, imo. Without air to support, I think the air shocks will not function very well, and could even cause damage to the shock.

Scott if you fiddle with the rod going to the control box it may be possible to adjust it to work with the new ride height. Tho I would imagine that would reduce shock life since they would be compressed more than normal.

Would going with regular gas shocks be a better choice for this situation?

I'm willing to be overruled on this, but I would think that even a normal gas shock would have the same problem of shorter life. Its never going to be in its optimum range. A variable rate non-adjustable shock would be even worse because they are designed to work at a certain ride height, any different and it will change the characteristics of the shocks. The solution is to have a custom built shock with a shorter shaft allowing less travel. You'd need to find a company willing to do it (there are some out there, can't think of one off hand) and be able to give them all the info they'd need, ie height, travel lenth, car weight, valve rate, spring rate, ect. Not easy or cheap but doable

J. Chris Davis wrote:

Would going with regular gas shocks be a better choice for this situation?

Probably not. I seriously doubt that resetting the control lever would be a problem at all. I suspect the instructions for your Eibach (if thats what you got) lowering springs probably said you had to do this reset in the fine print somewheres.

The Monroe MA-822 description does not claim that they are position sensitive:

MONROE MAX-AIR SHOCK ABSORBERS, SET OF 2 -- 24.38 in. extended length; 14.5 in. compressed length; With stem upper mount and cross-pin lower mount; Includes air fittings; Does not include air line and air valve kit; These nitrogen gas-charged, twin-tube shocks can maintain ride height when up to 1,200 lbs. of additional weight is loaded, making these ideal for vehicles that haul heavy loads or tow trailers; Features all weather fluid containing special modifiers for reduced friction and smooth rod reaction, full displaced valving for better valving range on both compression and extension for a smooth and comfortable ride, sintered iron piston that is stronger than traditional metals to enhance durability, lubricated air sleeve to reduce friction and provide smoother operation during suspension movement, special air fitting to resist air leakage, 0.5 in. hardened and precision ground piston rod for consistent performance and long service life, and large volume air chamber that can inflate up to 150 psi with loaded vehicle and deflates for normal driving.

(source - http://www.autopartswarehouse.com/performance_sm/monroe~struts~performance.html, today)

If your currently-installed shocks are worn or not holding air if I were you I'd reset the level control to the right height then install the KYB replacements.

The Monroe self-load-adjusting replacements (no air connection at all) **DO** have position-sensitive damping.

The Monroe® Sensa-Trac® load adjusting shock absorber with PSD (position sensitive damping) and the Safe Tech™ system combines our exclusive precision tapered grooves in the pressure tube with application engineered valving and Fluon banded piston to improve the ride, handling, and safety characteristics of the vehicle.

(source - http://www.monroe.com/products/Sensa-Trac, today)

I wonder if they are basically Nivomats with progressive assist springs but I really don't know.

Thinking out loud so to speak, Gabriels with VST ought to work fine in this application, they are intentionally not position sensitive by design.

What I would do (for what it's worth)

- if I have a different vehicle for hauling passengers around or taking family/highway trips, I'd consider converting the Riv to Bilsteins and having a set of progressive springs wound -- get rid of the air ride. Bilstein makes an outstanding monotube gascharged shock. I put them on an Audi I used to own, 2-stepped them from Europe so as to get the ones valved for there rather than for US (too soft IMHO). This would be only if the Riv was strictly a personal recreational car. Ride height then would be defined by the new springs.
- if I want to be able to use the Riv for occasional or even frequent trips with any additional passengers, or 2 passengers and luggage, or to haul occasional loads (bags of water softener salt or what have you) then I'd keep the air-ride and install KYB, OE or Monroe replacement shocks. It is a 45-minute job startup to cleanup. You can reset the ride height but getting the camber right will be a custom-parts-faricatino headache at best, I wouldn't bother.
- what I have on my car: I am on my 3rd set of OE air shocks. First set of replacements came from GMPD, second set from rockauto.com. If/when I need to replace the current set I plan to get KYBs and definitely keep the air ride. If I can find one or disassemble/recharge it I plan to replace/refresh the dryer. I can get the dessicant on eBay but don't know any more.

Has anyone done the Monroe coil conversion for the back shocks to eliminate the air pump?? I was wondering is this would be a viable way to save a little weight and reduce the possibility or future failure of the pump. also, how does one go about lowering these cars? I tried to look in the write-up section and have not found much.

GreenMonster wrote:

Has anyone done the Monroe coil conversion for the back shocks to eliminate the air pump?? I was wondering is this would be a viable way to save a little weight and reduce the possibility or future failure of the pump. also, how does one go about lowering these cars? I tried to look in the write-up section and have not found much.

There is no adjustment for camber at the rear. If you lower the back of the car below the stock ride height, the rear tire camber will go negative.

When I bought my Riviera, the ALC was non functional, and the back of the car was very low. One of my friends who was following me one day, noticed the rear tire camber and told me about it. When I brought it in for an alignment, I was told there was no adjustment. We were able to lift the back of the car while it was on the alignment rack, and see the camber change. I followed the diagnostic in my FSM, and found a broken wire between the back seat relay, and the level sensor. Ran a new wire and the ALC works to this day 7 years later. It's a pretty good system. If yours isn't broken, I wouldn't try to fix it.

The pump is working fine however the suspension is getting extremely soggy, and the air pump seems likes its on alot more than it needs to be so I assume the rear shocks are leaking. I guess I'll just replace the struts and shocks with new units and just call it a day.

New shocks will firm things up, but if the pump is on a lot, there's probably a leak. My pump burned out shortly after I noticed it was on a lot. A $15 air line kit was the option I chose - replaces the pump and lets you manually fill with air to set the level of the rear.

GreenMonster wrote:

The pump is working fine however the suspension is getting extremely soggy, and the air pump seems likes its on alot more than it needs to be so I assume the rear shocks are leaking. I guess I'll just replace the struts and shocks with new units and just call it a day.

Not sure what "soggy" is, but yeah, I would replace the shocks and/or check the lines. If the compressor runs a lot, there is a leak somewhere.

Is there a writeup here for the part Aaron mentioned above and how to set the level of the rear? I might be dabbling in some interesting things soon.

good info here. what about installing the coil conversion to eliminate the pump all together?? I can imagine the pump and system weighs a good amount.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Conversion-Kit-Monroe_10020739-P_2553_R|GRPCHASAMS_1527370456____

Actually you'd be surprised, I just pulled the pump assembly out and its fairly small for what it does and it doesn't weigh very much. I'd estimate between 5-10 lbs. The air shocks are a bit bulky, but I imagine that a shock with a helper spring wound around it wouldn't be much lighter if at all. If you're looking to shave every pound then I understand but a riv isn't exactly a lite weight and likely never will be.