I just bled the brakes on my '97 I6, and I now have a problem. When I go to stop, the brakes work fine until I'm almost stopped. Then the pedal sinks a little and judders for a second or two, and then firms up again. No warning light comes on or any sign of a leak. ABS is working fine too. Apart from that, the brakes work fine.

The brake pedal holds firm when testing with the engine off.

Anyone know what I've broken?

Rob

 

look up the proper procedure to bleed the abs unit. that judder (from your description) is your abs pulsing.

edit, also...did you replace any parts?

 

No new parts were fitted, just the brake bleeding done.

According to my service manual, to bleed the ABS sytem a "DRB scan tool" is required.

Anyone got one I can borrow?

Rob

 

You handle the plane tickets and lodging for me and the wife. You can use mine.

 

Might be cheaper for me to do it the "Highland way";

Bleed brakes, go for drive on wet deserted road and carry out multiple ABS stops, bleed brakes.

Rob

 

have fun with that.

 

sometimes the "judder" is caused br a wheel speed sensor dropping out, this causes the abs to actuate , it is trying to release brake pressure to the wheel it thinks is locked.
Good luck!
P.S. you shouldn't really have to bleed the abs unit unless the system went empty(ie. blown brake line) usually bleeding the base brakes works.

 

Problem solved.

At the same time as bleeding the brakes I fitted a rear locker. During the install I must have knocked a rear ABS sensor out of position. One of the rears had a obviously larger gap than the specs I've got (36-50 thou'). Using technical know-how and precison instruments (hammer and chisel), I adjusted the gap.

Took it for a spin and all's ok again. Thanks all.

Rob