2000 RL brake mystery

[younglifeunc]

The following occurs ONLY when the car is first started and going down my driveway (gentle slope) very slowly with me applying my brakes the whole way down: the brakes are fine and then all of a sudden, the brake pedal goes down just a little bit (not too much), a noise near the left front part of the firewall occurs (kind of like a grinding), and the car surges forward until I press harder on the brakes. Then, after occuring one time, it doesn't occur again during the way down the driveway or at all for the rest of the day. What's going on here??? The dealer can't figure it out because they couldn't replicate the phenomenon, and my brakes are brand new (i.e. they've been bled, and the master cylinder doesn't visibly leak).

[tytyguy]

is it a manual or auto?

[younglifeunc]

It's an automatic tranny...

[SIGP220]

I had a problem with my brakes back in the summer where the pedal would go to the floor like you describe except with no noise. I had no visible leaks from the ABS or Master cylinder or Brake Booster. I bled the brakes and everything. Once I replaced the master cylinder the pedal problem went away. I forgot how we figured out the master cylinder was bad but we did some good old "shade tree" trouble shooting!!! I found a good price on the master cylinder @ racepages.com. they have really good deals on Acura parts unless you know someone who works at a dealer and can discount for you.

[younglifeunc]

Thanks for the suggestion! I'll probably go ahead and install a new master cylinder. Which master cylinder did you buy from racepages.com (Raybestos, Centric, Beck Arnley)???