Vehicle: 2001 Honda Civic HX (1.7L 4cyl “VTEC-e”) 5 spd manual, AC, power brakes, no ABS, acquired used 3 years ago.
Symptom: occasional minor brake pedal fall-away co-incident with the AC compressor cycling off (it happens ONLY when the AC compressor cycles off, but not every time it cycles off).
I’ve only ever noticed this after idling at a full stop for 30+ seconds of steady light pressure on the pedal, trans in neutral (like at a stoplight)(engine already at operating temp).
My first thought was imminent master cylinder failure, but the degree of pedal fall-away (slight) has not changed in the 3 years since I first noticed. I usually completely forget about it during seasons of extended AC disuse.
Question: is this merely a minor quirk of the 7th generation Civic within the realm of “normal” operation? Or is this a repairable vacuum issue?
My 1992 Accord has done this since new. It’s normal.
Thank you.
Anyone want to second that (or disagree)?
I don't know your car so this is a real SWAG, Check out your vacuum lines, looking for a leak (don't forget to check the hoses for splits that are difficult to see.