Faulty "Bomb" infos

[Pisobiker]

Hi guys,

need some infos about most common faults produced by a dodgy bomb.
Never had the need, so I actually don't exactly know what kind of problems does a faulty bomb cause, nor how to check if it really is the bomb needing to be changed.

Here is the problem:

I have a friend in Rome whose RS2 flashes the ABS light very frequently. Audi service say the bomb needs to be replaced (I haven't had the chance to test the car so I don't know how the pedal and overall braking feels).
What should I tell him to look at?
How much does a new bomb cost (Martyn?) and how much a reconditioned one?

Thanks

Marco

[Mihnea]

Marco, AFAIK a bad bomb can never make the ABS light flash...

HTH,

Mihnea

[Pisobiker]

Out of topic Mihnea, this guy might send to you a mail asking for a chipset soon .

Marco

[Mikes2]

If the ABS light flashes while driving it could be a faulty or badly seated sensor.

Other things it could be are the controller, the pump, the wiring, the fuse, the relay or the rear diff switch.

I would check all the elctrical items to make sure they are seated correctly.

VAG Com will throw up the cause of the fault but don't see how the bomb can cause it. The ABS is electrical, the bomb is hydraulic

[Graham]

On yahoo Uk i typed in "brake pressures" and it came up with an interesting read about a blokes problems with his audi Hydraulic system and a number of fixes. One surprising one which when i think might have cured mine. My oil was like sludge and this sludge prevents the bomb check valve from shutting properly and allowing some of the pressure to leak back into the system.
HTH
Graham

[Pisobiker]

Thanks guys.
Will talk to my friend and try to better figure out what exactly the problem is.

Any other suggestion welcome.


Ciao

Marco

[newsh]

To test the bomb, run the engine then switch off, now pump the brake pedal till it goes hard, count the pumps, a healthy bomb will give 15 - 20 or more pumps, less than 10 on the way out, less than 5 change it.

[audiman]

My servo has gone and leaks internally, gives no probs with the engine running. It brings the warning light on afetr pressing the pedal a few times with the ignition off. Im sure there is some very good info on http://www.s2central.net/brakes_02.html#bomb