Referring to 1993 940 Turbo Sedan 220,000 miles:

[ul][*]When I press on the brake, I can a) hear a hissing noise which sounds like a vac leak, b)the pedal goes soft, c) the idle surges over and over from 400 to 1300. This happens until the brake is released, and then the idle settles. [/ul]
[ul][*]Also, when i hit the brake and have the left turn signal on at the same time the warning light which indicates a bulb is out, flashes in time with the turn signal. When the left turn signal is on without the brake, it is fine, when the brake is on without the left turn signal, it is fine. And when the brake and right signal are used simultaneously, the warning light does not show. [/ul]
Thoughts and/or suggestions?

 

1. Brake Booster vacuum leak.

2. Bad connection or contact most likely in the rear lights. My 945 has the same intermitent gremlins. The sockets get corroded, the contacts weaken. Have to look the whole system over, all the bulbs, contacts, grounds, etc.

 

thanks!