Brake booster issue, opinions wanted / welcome
 

My '84 4KST has recently developed an issue with the brakes. I am thinking my brake booster may need replacing, but would welcome any opinions before I start buying parts.

Symptoms -

Brakes feel ok at normal speed stops, but if you really need to get on them, they don't seem to lock at all and you really need to get on them very hard to stop in a "panic" situation. Feels almost like having ABS but without the stopping power.

Also I am definitely hearing a hissing noise from under the dash (from the brake pedal) when the pedal is fully depressed to the floor.

Pedal does return to the full upright position without having to use my foot.

Having had issues with a bad MC in my CGT before I can tell you that it does not feel like the MC is bad, the pedal isn't sinking to the floor.

Again I believe it's the booster, but would love to hear other opinions.

J.

if engine is off is pedal hard to push the first time?

if engine is off is pedal hard to push the first time?

Pedal is very firm with engine off. Softens up when engine is turned on.

sounds like the booster to me.
 

see if you can put a vacuum on the supply line and see if it holds. My bet would be no.

Re: Brake booster issue, opinions wanted / welcome
 

i make custom block off plates and gaskets check the link<ul><li><a href="https://forums.audiworld.com/i5/msgs/3506.phtml">https://forums.audiworld.com/i5/msgs/3506.phtml</a</li></ul>