Large difference between %CO in P/N & 4/R

[Berggreen]

Great, thanks I will definately try this out, to rule out that I am reading a false lower %CO when in gear! I assume this would be the consequence, if the brake booster is leaking and thus giving the engine more air, when pressing the brake at idle in gear. Is that correctly understood? :-)

Thanks again,

Christian :-)

[jeffc280sl]

That's the theory.  There is a bolt connecting the master cylinder to the brake booster.  There is supposed to be a bushing that prevents over tightening of the bolt allowing the master cylinder shaft to rotate slightly so the booster seal makes full contact when depressing the brake pedal.  That's my hard earned lesson.

[Berggreen]

That's the theory.  There is a bolt connecting the master cylinder to the brake booster.  There is supposed to be a bushing that prevents over tightening of the bolt allowing the master cylinder shaft to rotate slightly so the booster seal makes full contact when depressing the brake pedal.  That's my hard earned lesson.

Super, thanx, I will check that and report back. :-)