Well, I changed the fluid again this wknd and same results. It has been above normal in temps outside here in Ohio, but today was first time where the car sat out with temps below 30 all day. When I drove off and at my first stop only 200 ft away, as I pressed on pedal, it went down, started to stop and then continued on for a bit more and then stopped again. Did not do this again. I am going to try the brake booster check valve first and then master if that doesn't do it. More to follow. How do you bleed fluid at master? Is it the two bleeder screws just below the fluid holder?

bleed the brakes. If the problem still persists, you probably need a new master cylinder.

Hello, Before you go to all the trouble of bleeding the brakes again, try bleeding the master cylinder, most times air gets trapped when fluid has been changed. Pauli

Those symptoms are usually either air in the system or a master cylinder which is on it's way out.

Proper bleeding of the ABS equipped vehicles can be tricky. Sometimes I find that I have to go around the whole car two or three times with the bleeding process to really get 'em right.

Sounds like air in the system; I'd likely re-bleed the system. However,I would still check very closely for leaks at the calipers and hoses. Check also for a vacuum leak at the brake booster check valve. If you are sitting at a light with your foot on the brake, does the pedal go progressively lower the longer you sit? If so, I would strongly consider the master cylinder. Alternatively, the master cylider is only about $135 at FCP Groton, thus if you are going to open the system to re-bleed (and are worried that the master cylinder is weak), it would be a great time to just change it out anyway. Hope this helps, Jim

Did this start as soon as your brake fluid was changed?If so,it could be air in the lines.Have the brakes bled carefully.Check for fluid leaks-are you losing any? If problem persists after this,you probably need a new master cylinder.
sredwine 98 V90 has 125K,94 940T has 183K