Q: Braking issue after engine warm-up

[Michael Hartman and Donna Bissey]

I have an Alpine series V, which I recently inherited. It has been driven very little the past few years. Around two weeks ago I took the Alpine for a short spin and the brakes stuck on partially after coming to a stop. The car was still drivable. Initially, I was thinking the brake stick was due to corrosion in the calipers. But this seems to be a problem only when the engine is warm. Last night I idled the engine to warm it up and the brake lights came on by themselves. The brake lights are controlled by brake fluid pressure not brake pedal position, right? Any pointers for what steps to perform to resolve this would be appreciated.

Thanks,
Michael Hartman
Wilmington, DE

[dtjohnson]

Mark

Are you still using a brake booster? Sounds like the
seal in the plunger inside the canister is hanging up.
Could also be the vacuum valve in the booster is
leaking air to the can and applying the brake.

Remove the booster and and install a brake booster
bypass. Its usually two unions and a short 4 inch
brake line with the proper ends. Be careful and
you may only have to bleed at the last union.

Now drive the car. You’ll have to push the pedal a
bit harder. If the brakes work fine, your problem
is in the booster. Most race car drivers race their
Alpines and Tigers without the booster. They are
just too unreliable.

If the brake problem persists, you’ll have to think
about (1) a weak pedal return spring or (2) A weak
or broken spring in the master cylinder.

The brake light switch is hydraulic and notorious
for failing or no turning the brake lights on unless
you push hard on the pedal. Easy stop can lead
to some idiot running into you.

Go to http://www.TigersUnited.com and look up how
to replace that switch with a modern electrical
switch. A worthy modification.

Dave Johnson

[anonymous]

Leave that booster off (or install just for looks)….to improve pedal power without booster switch to a smaller bore master cyl. Early Alpines have a smaller bore than later series, some owners use datsun dual MC set-up…also check out http://www.wildwood.com…….later Alpines use a 7/8 , early is 3/4 I think…….Mike in Florida

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