Boost Drops

[irie]

It's possibly the brake booster. It's also vacuum-controlled and the hissing sound near it may be a clue there. The diaphragm in the booster fails (rarely, but it has been reported here a few times). You can usually tell by the brakes not performing like they used to - it takes more effort on the pedal to make the car stop.

In an attempt to diagnose, is it possible to remove the vacuum like from the brake booster and plug it?
How difficult would it be to brake without the vacuum assistance?

 

[Old.Tony]

In an attempt to diagnose, is it possible to remove the vacuum like from the brake booster and plug it?
How difficult would it be to brake without the vacuum assistance?

It takes a firm foot to brake without the booster. With it, my car stops quite easily (hardly any "pushing" of the brake pedal. If you remove the vacuum from the brake and there's little difference, you've found the problem. Usually when the brake booster leaks vacuum, the turbo is affected.