Need some help please. Helping a friend bleed his brakes after he had fitted new rear discs and pads and despite having bled all 4 wheels we can get no pedal at all when the engine is running. There is something there before you start the engine but when you do the pedal goes straight to the floor.
A few points to note:-
i/he had the calipers off the car to wind the pistons back
ii/ he noticed a split servo hose and replaced this.
Any ideas- have not come across this before?
many thanks
Incidently when Haynes talks about RH first is this from the driver,s seat?
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Did he break into the brake pipes or not. This may require a vag-com to turn on the ABS pump to bleed the system, that's why they feel OK with the engine off. Regards Peter
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Just a thought - how about bleeding them with the engine running?
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Obviously undrivable,so ,get yourself 4 brake pipe clamps(not dear)and clamp every(4)flexipipes.does this improve pedal?if so systematically remove clamps one at a time and retest.with luck this will show where fault is and u can concentrate your efforts there.note:one time the only way i could get a satifactory pedal was to retract every piston by loosening bleed nipples NOT by forcing fluid back up pipes,then clamped all calipers in the full back position then i bled the system.unfortunatly this worked,so i never found out the original reason for soggy pedal.
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If you look at the brake master cylinder you will see a bleed nipple at the end of it. Connect your brake bleeding pipe on here first and open the nipple, give it a couple of pumps and close it again. Then bleed the the brakes starting from the furthest away ( this should be the N.S.R, O.S.R, N.S.F then finally O.S.F ). Always ensure that the master cylinder is topped up at all times.
Hopefully this should get you back on the road again :)
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I was once told that you should only bleed the brakes on an ABS equipped car by using a pressure bleeding kit and then only after disconnecting the battery, or air could get into the ABS unit which can be very difficult or impossible to get out.
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Thanks to all who replied eventually got it sorted.
Used the pressure bleeder on all 4 wheels : didn't seem to purge much air and there was still no pedal resistance.
Then bled both the bleeding nipples on the the master cylinder and again didn't note any air coming out. However this must have been the problem as the brakes are now working fine again.
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