A mechanic recently told me that the dark brake fluid in my resevoir is an indication of a bad master cylinder. I could not get him to change the brake fluid without replacing the master cylinder, and he refused to work on my front brakes unless I also replaced the master cylinder. This would have increased a $500 job to $900+.
I agree that the brake fluid should be changed, but is it a bad idea to bleed dark brake fluid through ABS brake systems (and the new calipers that he also wanted to add on)? Even if he replaced the master cylinder, wouldn't this dark brake fluid already be throughout the entire brake line? He was adamant that the master cylinder was bad based on 1) dark brake fluid and 2) increased downward brake pedal travel.
Am I crazy, or is this overkill?