Can a brake booster leak cause an engine misfire?
Can a brake booster leak cause an engine misfire? An internal brake booster leak may manifest itself through an engine misfire. If an internal valve or the diaphragm has failed, it may cause a leaned air/fuel ratio and a misfire as you step on the brake pedal, usually at idle. What to do if your brake booster drops to zero? If booster vacuum remains at 20HG or drops to zero, replace the brake booster. Apply vacuum to the booster with the pump to bring it back to 20HG. Depress the brake pedal and hold it down for 30 seconds. You...