do i want to much

[LucN]

this winter i've replaced front caliper ,discs and compensator, the back calipers where replaced last year, while i tought to have a real good brake system, i still need to push the brakepedal real hard to get a descent brake distance.
do i want to much from my 79 spider or do i need to improve something else?
are you satisfied with your brake system?
Luc

[baltobernie]

Do the brakes work better if you press the pedal several times?

[vandor]

I you have to push hard then likely the booster is not working. First off check that the hose from the manifold tothe booster is not kinked and has no leaks. It has to be a special hose that does not collapse under vacuum. People often use heater hose instead and after a while the hoses collapses.

[LucN]

Hi Baltoberni, no, this doesn' change the brake performance

Hi, Vandor, the hose is not kinked, any idea how i can test the booster?

Luc

[vandor]

Not sure, if you are sure it's getting vacuum and the brakes are hard to push then I'd say it's bad. Normally the brake pedal should not be at all hard to push for fast stops.
The booster has a check valve, so it sohuld have vacuum for a while after the engine is shut off. Normally one can push the pedal a few times just after the engine is shut off and the booster will still give some assist. If there is no difference in the pedal feel with the engine running or not running and the booster is getting vacuum, then the booster must be bad.

[KevAndAndi]

When you start the car, do you feel the brake pedal pull toward the floor a bit? If you don't feel that, it's another clue that the booster is not working.

[LucN]

Hi KevAndAndi,

indeed, the pedal goes a bit towards the floor the moment i start the car.

Luc

[DieselSpider]

Did you replace the rubber lines at each wheel? When they get old the central liner can start to shred and partially block the line during hard braking otherwise you may have still have a defective vacuum hose, check valve or booster.

[LucN]

nope, i didn't replace the lines, thx for the tip!