tiderunner85

Just bought an 03 allroad last week that was basically sitting on the front bumpstops. PO said car had been fine then over a short time period the front bags stopped working. The rear looks to be at a normal height. I put arnott bags on the front hoping it would fix the issue but that didn't work.

The compressor will run, sometimes with a lot of rattling, other times sounds like I'd expect it to, but the front end doesn't move and I do not hear any air leaks. The suspension light on the dash blinks for awhile on startup then goes solid.

Installed VCDS lite last night and got this. Battery had been dead so not sure if that's why the low supply voltage fault came up.

Wednesday, 04 February 2015, 22:41:28.
VCDS-Lite Version: Release 1.2
Control Module Part Number: 4Z7 907 553 EF
Component and/or Version: - 2C1A1 X040
Software Coding: 25500
Work Shop Code: WSC 23253
VCID: 8D6DAA37D449
2 Faults Found:
01400 - Suspension Level Control
53-10 - Supply Voltage Too Low - Intermittent
01400 - Shareware Version. To Decode all DTCs
11-00 - Please Register/Activate

I cleared these and then tried the whole process over and got this fault...

Wednesday, 04 February 2015, 22:48:17.
VCDS-Lite Version: Release 1.2
Control Module Part Number: 4Z7 907 553 EF
Component and/or Version: - 2C1A1 X040
Software Coding: 25500
Work Shop Code: WSC 23253
VCID: 8D6DAA37D449
1 Fault Found:
01400 - Suspension Level Control
11-00 - Control Limit Not Reached

I also noticed the tank pressure would hover around 4.5bar.

Thoughts? My guess is I'll be rebuilding the compressor next?

raj99

The max compressor output, for a new one, is 16 BAR. You are well short of that.

tiderunner85

Kind of what I expected. What goes into the decision between buying a rebuild kit or a new compressor? I may take a look at it tonight...

raj99

Attempt to rebuild first. The cost of complete replacement is significantly higher, so if the rebuild doesn't work you know what your next logical step will be.

tiderunner85

Rebuilt the compressor and good to go! I'll have to check the vagcom to see what pressure it's getting to but seems to lift it pretty quick. Thanks!

bagpipingandy

You wont see 16 bar with VCDS as VCDS shows the in tank pressure which depends on what stage you scan it but it will never show 16bar, you will get 16 bar if you stick a pressure gauge directly in the compressor output, but ultimately a fast lifting car means the rebuild has done the trick,

however if it is sinking to the bump stops when parked, especially if left at level 1 you have a leak and you must fix this as it will only wear out that compressor again,

if it sinks at level 1 but not at level 3 this is the airbag leaking, best to replace with new one,

best regards

Andy