Started going through Brake fluid. Filled the reservoir up last week and the light is back on 6 days later. all the calipers and lines are dry.
Looks a little damp below the master cylinder. How tough of a job is it to change one out. Also any sites that break it down would help. thanks.

It looks like it is coming from the brake proportioning valve.
How tough to change out and any sites for instructions to change out? Thanks.

Double check your diagnosis and make sure that it is not the brake proportioning valve that sits right under the master. I have yet to change an 850 master cylinder for leaking and I have changed countless valves for just that.

mark

Just had mine brake proportioning valve changed by the dealer, $2400. Part alone is like $1700.

Michael

you could buy a whole car for 2400.00 Holy shit.

No, the brake proportioning valve is only about $100.00 for a sedan and closer to $160.00 for a wagon. It should've only run about 2 hours labor to change it out and flush the entire system. Sounds more like you bought the whole darn pump/modulator assembly.

Changing out the proportioning valve or the junction block as some parts data bases refer to it is really a piece of cake.
Pull the the air box out of your way.
Break all of the lines loose before you remove the two screws that retain it. Remove the screws and change out the valve.
Start all of the lines before you tighten any of them, start the retaining screws and then tighten everything up.
Bleed the entire system out and hose everything off with brake spray clean and or water and you should be good to go.

Mark