My 307 1.4 hdi (2002) failed the mot this week with "brake pedal spongy" , also "brake pedal has no servo assistance" as well as an abs fault.
Got home read codes and found rear left road sensor permanent fault incoherant. Did no more than dismantle the back left brake assembly, remove the abs sensor and then chisel off the build up of rust and crud to provide a flat surface and checked the sensor before assembly using PP2000 and a fridge magnet
. This was proven to pick up fine, so reassembled brakes cleared codes, took it for a run but the brake pedal is still poor. Abs fixed though.
Pressing the brake pedal with the engine off does leave the brake with a fairly stiff brake pedal however on start up the pedal sinks and continues to do with out going right to the floor.
Took off all the pipework between the servo tank, cam driven vacuum pump, turbo vac solenoid and return pipework to egr valve and carefully examined pipework throught but all appeared okay and stood up to a pressure test.
Even checked one way valve from servo and that does work in one way only from servo to vacuum pump. Built it all back up started engine and cam driven vacuum pump does seem to work although i need a gauge to check what value this is.
Tried bleeding the brakes conventionally and then got confused trying to bleed it the Planet peugeot way when it switches on the abs unit for 10 seconds at a time as by the time i could press the okay button and got someone to continually pump for the 10 seconds i hadnt much time to open a bleed screw!
How do you bleed the abs unit unit using planet peugeot 2000 just so i can rule out the abs unit as i am thinking it could be the master cylinder or at least half of it...unless its full of air.
Please could someone help me. Thank you