right, i have a mk4 fiesta, has the standard non-abs servo and m/c. (4 outputs - 2 to front, 2 to rear through an AP racing twin pass bias valve)
i run focus rear discs and brembo 4 pot front calipers. this setup before my engine conversion worked perfectly every time with no squishyness, or sinking pedal. (when on original m/c. hard lines + braided flexis, standard bias valve thingies)
i've had a problem with them ever since my engine conversion.
at that time i fitted:
new servo
new m/c
fully braided lines from m/c to caliper
AP twin pass bias valve
and the vacuum is now off cyl 1 (throttle bodies) instead of off the plenum of the original engine.
i'm still running Dot4 brake fluid (but im unsure of the quality)
my symptoms are:
sometimes when i hit the brake the pedal goes almost to the floor, hit it again and it has regained pressure.
if you pump the brake up then keep applying pressure the pedal slowly goes to the floor
the system has been bled through numerous times, various orders and different ways... taking calipers off, turning upside-down etc but always with the same brake fluid. (cant remember when i bought it, although it was quite a few years ago).
before i go mental, and start replacing stuff, anyone got any ideas?
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