cameltrophyallroad

2001 AR; the pump runs as soon as i start driving, for a while, it'll shut off, then kick on again. All bags are new and do not leak at all, maintains height overnight all levels. When i start driving the car it runs, not while the car sits and warms up, and it is loud because of the rear aftermarket sway bar, and because it it also is louder than the other car, (i have two 2001 ar's.) Car #2 all bags are new, i never hear the pump unless i change the height. On the car in question; I have #1. rebuilt the pump with bagpipe Andy's kit, made no difference, #2. customized the attachment points so it doesn't touch the sway bar, but it is still loud and in my opinion, comparing it to car #2, runs way too much. the height adjustment is set to manual, so it doesn't change height automatically either.

Does this sound like an old and tired pump?

Air reservoir leak?

any info as always greatly appreciated.

swamper8

So a couple things:
Just because the car sits level all night doesn't mean there isn't a leak. The reason is that the car will continue to keep itself level all night by tapping into the reserve tank air as needed. So many AR owners have small leaks in their systems but never realize it until they let the car sit for 2 or more days. Once the reserve tank has been emptied, you'll start to see the car sag. (if the problem is an air spring) So the way you eliminate the possibility of an airspring is to lockout the air suspension before you shut the car off at night. Do this by pressing both UP and DOWN air suspension buttons until the green lights on the buttons stay on and the orange dash lamp lights up. This will prevent the ECU from attempting to compensate for slow leaks during the night. Your pump is probably running so much in the morning because it is filling the partially depleted air tank back up.
Also, it's not a safe assumption that just because the bags are new doesn't mean there isn't a bag related leak. The bags are sealed to the shock and upper mount with 0-rings. There could be leaks at these spots. Or, there could be a leak where the air line enters the air spring.
I have the aftermarket Hotchkis sway bars and my pump does not hit them. There is a small amount of adjustment in the rear sway bar (up/down) so maybe yours is too high up. I know this because if the bar is too low, access to the rear alignment cam bolt is blocked. Local alignment shop wouldn't touch my sway bar so I had to move it out of the way myself so they could perform the alignment.
You could also try buying new mounts for pump. It's basically just a custom rubber grommet and a spring. I rebuilt my pump once. It was a bandaid. Probably restored 75% of the function to the pump and lasted only 6 months. I eventually bought a new one. Worth the money.
Find your leak before you buy a new pump or your new pump will wear prematurely from running too often. I have a spray bottle filled with a diluted soapy water solution that I use to find small leaks.

amiram

You can leave your car for night in "Jack mode " In this mode The system does not Makes any Height correction.

PetrolBear

Hi,

"The reason is that the car will continue to keep itself level all night by tapping into the reserve tank air as needed. "
do you have a source on this?
Nowhere I could find any info on this, neiter in the SSP nor form mechs. Personally I found contrary to this. SSP wrote that leveling is posssible only downwards. Mean: front left looses air, front right will be aligned (if the diff exceeds 5 or 6mm) in case the difference between the front and rear axles will be too high (approx... 20-25mm?) the higher axle will be adhered to the lower one. If you have a rear leak, the front will be lowered to that level and so on.

The fact that the pump kicks on after engine start and ride above 35km/h is completely normal. The tank is never fullfilled during parking. According my previous mech, certain amount of pressure is released, plus, the final leveling after engine shut off also consumes some air.
After cold start, a new compressor also runs for approx 50-60 sec or even a bit more up to 100 sec. Depends basicly on the number of previous levellings, height settings (how empty the tank is) prior to shut off.
That is the normal operational case.

If you have a leak or the compressor is worn out, it works much more. A worn compressor cannot fulfill the tank, it must deliver above 16,5 bars to comply with. A partially worn compressor often kicks in during traffic lamp waitings (levellings) too. From experience, mine produced aroung 11,5 bars as it acted like this. I replaced and height adjustments were managed from the tank ( one level change took approx 8-10-12 seconds) and compressor kicked in only during travel (above 35km/h).

cameltrophyallroad

good intel there. per the notion there could be a leak, i have left the car at the airport for 9 days and it was still fine so i'm more inclined to entertain other possibilities, like a bad pump. as far as the car leveling itself over night, in all my experience with the other car i've had for ten years, it only levels itself when a door is opened in the morning, or right after. i have never seen evidence the car levels itself, by itself, with the reserve air, but maybe i just haven't been paying close attention. i will look into these possibilities, thanks again.

amiram

The first reason that comes to mind is the manufacturer. This is a bad publicity when most Audi Allroads stand crooked