Servo-air leak-brake master cylinder question.
Never got interested in how brake servo works, nor any problems still, but i have doubts that something's wrong.
Here's the symptoms: 156 V6 2.5
Idle generally fine, but there is bit of up and down in revs, when stationary, maybe 20-30rpm sequently up-down. Brakes rock solid, never loosing even drop of brake fluid, same level month after month. When engine running brake pedal is bit soft when pressed easily, becomes harder when pressure increases. But when engine stops, it becomes immediately harder. Softened when engine start with pedal pressed. No change when using different TB, spark plugs, or pedal potentiometer. Reaching 640kgh air mass according to Alfadiag.
Maybe it will be good idea to remove the 2 master cylinder nuts, and check it's rubber seal(have 2 spare servo's with mast cyl, and i'd take a close look on it), and check idle with servo vacuum hose removed.
Rear Wheel Drive Mid - Engined Alfa 156 3.0 V6 '99 - trackday car
Alfa 156 2.0 TS '00 - daily car
Fiat Coupe 20VTurbo, GT2860RS, water-meth injection 120cc, custom manifold, 3" Downpipe, FMIC - entertainment car
Last edited by Speedmaster; 11-02-10 at 16:54.