# Audi 80 2.6 V6 Cabrio, Hydraulic Servo problem



## GTD. (Dec 5, 2004)

My Mate has a Audi Cabrio. The PAS pump was loosing fluid from a plug on the top of the pump next to the Banjo Bolt that feeds the Pressure accumulator (BOMB). The Brake Pressure warning light is flashing on on the dashboard. 

The brake pedal feel has gone very hard. 

I fitted a new O-Ring and a copper washer to seal the pump and refilled the system with G002000 Fluid (Pentosyn). 

I bled the Rack by going from lock to lock till the Pentosyn tank was free of bubbles, but the pedal didn't improve the pedal move an inch at the most then pulses like ABS feedback. I Removed the ABS fuse the pedal still judders. 

I tried empting the Pressure accumulator by repeatedly pressing the brake pedal without the engine running. but nothing changed the pedal is still hard. 

I loosened the union on the bulkhead/firewall for the pipe from the Pressure accumulator to the servo it weeped fluid but not at the high pressure I was expecting. I then did the same at the servo supply and return unions it did flow out but not under high pressure. 

The PAS works fine but the brake booster (servo) doesn't. 

New Pump Bomb or servo time? or have I done something wrong


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## carlosabh (Jan 21, 2003)

www,20v.org 

there is a bible there regarding abs pump diagnostics for the Audi 80 and 90.


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