brake issue

[preston03]

I bought my yaris in February, no problems til now. I was pulling out of a parking lot onto a street that went downhill, as I was coming to a stop down the hill, the brakes locked up and I kind of skidded to a stop. Then a few minutes later in a drive thru, I was in Park at the window, and decided to pump the brake pedal. As I would hit the brake pedal, I heard a hissing noise. I've worked around cars for a while now, and the only thing I know that hisses that's involved with brakes is the brake booster. Is the brake booster a common issue with the 2009 Yaris sedan?

[preston03]

I'm taking it to the dealership next week. Luckily I bought the extended warranty, since we're past the 36,000 mile mark. I went and checked the lines and fluids this morning and couldn't find anything noticeable. But the hissing was still there.

[tk1971]

The only thing that can hiss on a brake booster would be the vacuum line. Did you check the connections to and from?

[yaris2010RS]

i have a 01 camry that made a similar noise (didnt lock up wheels or act differently) but the noise was coming from the gasket between the booser and master cylinder. all i had to do was tighten the 2 bolts on the master cylinder that hold it to the booster and it never made the sound again

[preston03]

I checked the lines and nothing seemed out of place. Brake fluid was full. I'm taking it with me to work tomorrow to look at it more. It's weird because the brakes still function normally, but I can still hear the vacuum leak.

[tk1971]

Can you pinpoint the noise while someone is pumping the brake pedal while you're looking under the hood?

[preston03]

Can you pinpoint the noise while someone is pumping the brake pedal while you're looking under the hood?

Our best guess is the vacuum line. I work at an oil change center, kind of like an oilstop, but the lube tech got under and listened and said he could hear it going through all the lines all the way to the rear of the car.