12-12-2011, 05:59 PM
Officially Welcomed to the 'Fest
Join Date: Mar 2005
Mein Auto: '04 M3 / '06 650i Cab
That sounds like a problem with the bleeding.
Originally Posted by bcorwin
.... My pedal feels a little soft at first application, but gets firmer if I pump a little bit. Any chance I screwed up the bleeding....
I don't have time at the moment to do my brake bleed DIY but here is a reader's digest version of the manual method, which is better than a pressure brake bleeder.
The best way to bleed is with two people, one pressing on the pedal and one opening the bleed valve on the caliper. Start at RR wheel, then LR, RF and LF. Use a clear tube and catch bottle on the bleed screw so you can see the bubbles and fluid condition. Remove old fluid from reservoir and refill with fresh fluid - use turkey baster or large syringe.
1) Tell the helper to pump the pedal a few times until it's firm. Have them press hard on the pedal and hold.
2) Open the screw then close it again before the helper hits the floor with the pedal. The harder they press the better - it forces out the bubbles. (which is why the 2 person method is better than pressure bleeding)
3) Tell the helper to release then re-pump and hold the pedal.
4) Repeat steps 2 and 3 until you see lighter "fresh" fluid coming out (about 6 to 8 pumps)
5) Check the fluid level in the reservoir - do not let it empty or you'll have to start over.
6) Move to next wheel and repeat steps 1 to 5.
The front wheels only need 4 or 5 pumps since the lines are much shorter. It is key to close the bleed screw before the pedal hits the floor or you will suck in some air back into the caliper. You can have the helper yell "floor" when they bottom out but you should stop the pedal yourself by closing the screw before they bottom.
Straight lines are for fast cars...turns are for fast drivers
'04 M3 - track
'06 650i Cab - daily driver
'02 Highlander - kid hauler
'01 330Ci - winter beater
Last edited by Yorgi; 12-12-2011 at 06:02 PM.