I have a 96 civic as my daily driver. As of late, whenever I depress the break pedal while coming to a stop, the idle drops and the car dies or comes close to it.

Yesterday, I put my foot on the brake pedal to start the car and all seemed well. But when I started the engine the pedal went straight to the floor.

Situation:
Changed the Master Cylinder - Same Result
Lots of Brake Pressure when Engine is off, none when engine is running
When I disconnect the vacuum line going to the break booster while the engine is running, break pressure returns.
When i reconnect the vacuum line, break pressure is gone again.
Fluid level is OK

Any ideas? I do not have a vacuum testing device.

Thanks

 

Booster is no good... if the boost leaks tech it is a vaccum leak... that explains your idle and cutting off prob... your booster is no good

 

Vacuum related issue for sure.

Carlos

 

Changed the booster yesterday and the problem still exists. Any other thoughts?