Bomb replacement audi 90 20v

[Bernard Littau]

> Hi all
>
> can anyone tell me please what is the correct procedure for bleeding the
> braking and power steering system after replacing the bomb, i presume the
> whole braking system should be pressure bled.
>
> TIA
>
> Iain

Hi Iain,

The bomb has no direct connection to the brake system, so the brakes do not
need to be bled after a bomb replacement.

I don't have a Bentley manual for the 90 20v, but that would be the place to
look for the correct bleed procedure for the hydraulic system.

My guess is that the system self bleeds.  Make sure the hydraulic fluid is
at the cold max level, then start the engine and check the hydraulic fluid
level.  Pump the brakes a few times until they feel consistent.  Check the
hydraulic fluid, then turn the steering wheel lock-to-lock a few times,
checking the hydraulic fluid level.  This should be done with the front
wheels suspended so there is no load on the hydraulic system.

After you turn off the engine, wait a minute, then count boosted pumps on
the brakes.  You should get 30-ish if everything is ok.

The bomb is not used by the power steering side, so if you only depressurize
the bomb, and do a quick R&R on the bomb without draining the whole system,
you need for bleeding would be minimal.

That being said, you should drain and flush the system completely to do good
job.  Some bombs fail due to crud in the valve rather than loss of pressure,
so it behooves you to get the crud out of the system.

You should also bleed your brakes while you are down there with your hands
dirty already -- bleed your brakes at least once a year :-)

Best,

Bernard Littau
Woodinville, WA
'88 5ktq
'86 4kq