Taxi driver and was working this morning ...... went to brake at a corner and had no brakes at all !!! scary stuff ... after a while normal braking returned then left then returned again .. took it o my mechanic friend he said sounds like a servo problem .. so we did a smoke test for leaks and sure enough the main black pipe from the servo to the pump was loose and easily shook ..... that would have explained the hissing .... the mechanic said you could not tape it up as oil contamination would destroy the tape in days and he said you could not weld it together as it was aluminium .the actual metal connector bit has broken ...he used some sealant on it and said he would have to replace the pump to do a proper job .. has anyone encountered this problem before an any ideas how to bond them together permanatley rather than fork out for a new pump ... thanks Guys

its leaking at the vacumn pump .. the sleeve onto the rubber pipe is broken ....he used JD Weld all he could he said.

this is a fault with both the superb and the passat the servo pipe as it enters the vacuum pump works itself loose and causes some hairy breaking experiences when driving at low revs. To repair get a flat bar and tap around the flange on the pump to re tighten it then apply either JD weld or apoxy glue as a safeguard