Questions for all air spring experts.

After installing new front air spring, car was flat in the front the next morning. The rear was normal. Used the soap and water test--no leaks anywhere.

As soon as engine was started, air spring pumped up to normal lever.

This AM, same thing. Car was flat in the front, rear was Ok--however, after opening door , front aired up to normal level.

Q#1: What did opening the door trigger to cause the fill up?

Q#2: Did that air come from the stored air that is in the canister, because I did not hear the pump come on at all?

Q#3: I did not use the new fitting that came with the unit---the fitting with the little plastic insert. I read, somewhere on the forum, that installers cut the supply pipe and pushed the pipe into the plastic fitting. Should I do that and should that correct the problem?

This has me stumped.

Cheers

 

Did you drive the car around at all ? It might be this that "fixes" the height after a spring change.
Just my tuppence !

 

Fraser----
My shop, where I do maintenance on my vehicles, is at our country home, which is about a 40 mile round trip from our home in town, so yes in answer to your question----thanks.

However, height wasn't a problem, the car raised to the proper level after the unit was installed. It was just the loss of air overnight that concerns me..

Cheers

 

Opening the door brought it out of sleep mode. It still sounds like you have a leak somewhere, though, as it should not lower all the way down overnight. Mine doesn't even lower when it sits for over a month.

 

cjd-

I would have to agree with you, but I know of nowhere else to look. Surely it couldn't be the pump, because the rears are not affected with lowering overnight.

It's strange, because the drivers side is where the new spring was installed, but both left and right lower the same. One would think that the right side would remain pressurized if it was the new spring with the leak. I may be out in left field about that, but my limited knowledge on the subject reasons that way.

Maybe someone else on the forum has the answer, so I'll keep waiting to see.

Cheers

 

You would think that only one side in the front would lower completely, but because they have to carry the weight of the engine, the whole front end will lower to prevent damage to the other air shock. You maybe a fault somewhere else, such as a ride height sensor, that may be triggering it. Did you replace the shock with a genuine or aftermarket unit?

 

for Chuck
Where did the new air spring come from ? Was it a Bilstein OEM ? Can I assume you get a fault code if you turn on the ignition ?


If the front drops overnight, there surely has to be a leak somewhere, because my car stays up for days on end. Only when I start does it sometimes do a little "adjustment" but that's it.

 

The '05 model removed one of the front height sensors, so it only uses a single front sensor, and 2 on the rear. The result is the front will lower as a whole, but the rear can lower a single strut.

As for the leak, it may not be at the strut. The valve block is under the spare tire in the rear, and the nylon lines lead forward to the struts...so the leak can be anywhere from the vlave block to the front shocks.

 

Chuck,

To answer one of your questions, as the car sits the air suspension will lower one or more corners to help level the car. When the car door is opened, the air suspension system wakes up, checks its current height and if necessary fills one or more corners using pressure stored in the reservoir under the spare wheel in the trunk/boot near the valve block as John mentioned. When the engine is started, after a short delay the air compressor will run for up to 2 minutes to replenish the pressure in the reservoir, unless you put the car in Drive before the 2 minutes elapses, in which case the compressor will stop running until the vehicle speed exceeds 25 mph (off the top of my head).

The document at the link below is the most detailed explanation of system operation I know of:

http://www.mediafire.com/download/7r...on_Section.pdf

Is it possible the car is parked at an incline ("up hill")? If so, it could simply be that the air suspension control module (ASM) is relieving pressure to the front air springs to level the car.

If the car is parked on a level surface, it does sound as though you have a leak somewhere. The air hoses attached to the air springs all go to the valve block, which controls the pressure to each spring (as John mentioned, the two front air springs are pressurized or depressurized as a pair).

It is possible that you have an air leak that is so slow you couldn't detect it with the soapy water test, but it would be worth testing the fittings at the valve block. It might also be worth replacing the fitting at the new air spring with the new fitting and compression ring or "olive" that was supplied with the new unit. Off the top of my head, I think the instructions are to trim 1/2 inch off the end of the air hose using a special tubing cutter that puts a nice square end on the hose. You can probably achieve a satisfactory cut using a razor blade and a wooden block as a "cutting board," doing your best to get a square edge on the hose. I believe our member abonano has posted about this process in the S-Type forum.

Please keep us informed.

Cheers,

Don

 

Maybe stupid, but could it be that, after having replaced air springs, it is needed to make a re-calibration (kind of teaching the sensors) using IDS-SDD?

 

Simple answer, that's not so simple, is that there is a leak. If the condition described above are in fact true. If it stabilizes level upon wake, then the sensors are calibrated correctly. It could be a faulty replacement air suspension module, a cut/break in the feed line, a solenoid or distribution block in the boot...

 

Thanks to all. I'll keep looking and if there are any other comments--all are welcome.


Cheers

 

There is a calibration procedure that can be ran using the sdd.