nosnow

Went for a drive and my brake fluiid light came on. It appears my ABS pump is leaking. Is there a place that rebuild/reseal? I have seen several used but fear the same issue. Picture below.

nosnow

It is an 89 s4.

Mrmerlin

based on the picture the rear brake bias valve is leaking this part can be replaced .
NOTE the original part is probably corroded inside,
.taking it apart will confirm this,
however the part will need to be replaced if its taken apart

NOTE you will need a helper to bleed it via pedal bleed.
replace the part then leave the B nut loose till you see no more bubbles .
then tighten the nut apply pedal pressure then crack the b nut open,
press pedal down then tighten the nut ,
repeat till the fluid is free from air .
then bleed the rear brakes.

NOTE if you have an original master cylinder then its likely that you will need to replace it due to going full stroke on the pedal,
this will run the seals into unused bore, the bore is usually corroded if you lose the pedal then replace the MC .
NOTE dont continue bleeding the brakes as you will push aerated fluid into the ABS unit
NOTE I suggest to use the ATE type 200 gold fluid

nosnow

Thank you, I didn't realize that was replacable as a seperate item. Any way I could use a motiv brake bleader or does it have to be the manual method?

Mrmerlin

you can try the motive bleeder,
but I get better results with a helper on the pedal,
maybe you will have a different result.
When i use a motive bleeder I put the cap on the reservoir and then pump up the tank ,
I dont put any brake fluid in the bleeder tank

nosnow

That is the same way I use it. I want to try and avoid doing a master cylinder. Looks like I know what I'm doing next weekend.