Hello everyone,
I have a 2001 Pontiac Grand Prix which I just had the back passenger side wheel bearing replaced about 4 weeks ago which after having it done it ran perfect.
But I'm wondering if there'* anything I can look for before the end of the weekend which I'll explain what happened. I worked last night which the car was parked for about 7 hours. And when I got off work I drove about four miles to pick up a friend at his job which my brakes worked fine. I went to the place to pick him up and parked in the parking lot which had a very slight incline and I waited 5 minutes and after he came out and got in the car, when I went to take off, my brake pedal felt like it wasn't as strong and eventually it started going down to the floor.But it will still stop me if I put it in neutral coming to a stop sign or somewhere I need to stop at, so I went to the gas station and got some brake fluid and I filled it up to the line which I had to fill up a couple times in the last 5 years just to top it off, but I never had it go down this far before. So I'm wondering if with the - 10 degree weather we have if it would do any kind of damage to make the brakes not want to work and allow the brake pedal to start off as normal and then after the foot stays on the brake pedal and it keeps going down it will eventually go all the way down to the floor just about. And also when I had the wheel bearing changed they looked at my brakes also and said that they were fine so I'm not really sure if it'* the master cylinder that needs replaced but I don't see any kind of leaks around the outside of the master cylinder and I looked last night with a flashlight behind the front tires after I turn them to each side and the brake line was still intact it didn't look like there was any fluid but it'* also hard to look when it'* been snowing all day yesterday and it'* wet underneath the wheel well. So if anybody could give me some steps to possibly look for that might help or if the braking system is set up on these cars where it will stop as long as I put it in neutral and drive careful because it seems like there'* got to be the front or the back brakes that are still working because it stopped me about 10 different times on the way back home last night but I need to go to work today and I need to know if I need to get a ride or not so I'm just wondering if anyone has any opinions or advice I'd appreciate looking into them. thank you

If the brake pedal gets firmer as you pump it, there is likely air in the system and your brakes need to be bled. If the brake pedal drifts to the floor and pumping does not firm it up you need a new master cylinder. That would be an internal leak, and would not result in dropping fluid levels. If you are having to fill the brake fluid there is a leak somewhere. Park your car over cardboard, pump the brakes numerous times, move the car, and look for brake fluid on the cardboard to help you narrow down where it is coming from.


It all starts with telling us what happens when you pump the brakes.