Ok i am experiencing somthing wierd with my brakes that i will try to explain best I can.... When the car is first started after sitting a resonable amount of time (10-20minutes) The first braking the car gets normally feels weak and is followed up with a grinding "feeling" somewhere in the brake system that is transfered through the pedal, it also doesn't feel like the brakes work to well when this is happening. I have never had this problem before, but i did paint my front calipers earlier last week... I don't know If i could have messed up anything but my guess would be I didn't since I'm not an idiot and don't see any way I could have shifted somthing around while painting them. I would appreciate any feedback...

 

It's the master cylinder. STOP DRIVING NOW before you get into an accident. Happened to me this winter. Brakes failed going 45 mph straight towards a van. Between the back of an 82 Caravan and a ditch, I chose the ditch and came out without any damage (whew).

Just go to Auto Zone and ask for a replacement master cylinder. Mine was $65 (there is an additional core charge).

 

I agree with what Z1 says about stop driving your car now, but I disagree with the diagnosed failure. The grinding is likely caused by worn brake pads. When the pads wear out, the backing of the brake pads begin to dig into the rotors. If you keep driving the car, then you'll need to replace the rotors along with the pads. That can get expensive. When you take off the wheels, if you can see groves carved into the rotor, then you'll likely have to replace the rotors. If not, then you can have a brake shop spin your rotors and you'll be good as new with new brake pads.


The master cylinder would need to be replaced if the following happened.....When you put constant pressure on the pedal, the pedal wants to drop to the floor. You'd need to pump the brake pedal with your foot to build the pressure needed to stop the car. It doesn't sound like this is happening, so the master cylinder is probably fine.