Odd brake problem...need opinions

[reiver62]

I have a 2003 Camry with 4-cyl, ABS and rear drums. I've always had a lot of brake pedal travel (goes almost all the way to the floor) which I've read is typical of the Camry.

- With the engine off, the brake pedal compresses hard about two inches, no bleed-down. When I start the engine the brake pedal immediately goes about 80% of the way down to the floor.

- Recently I have been getting bad pulsing from the rear under high-speed breaking. So I replaced the rear drums and bled all four corners. But I'm still getting pulsing from the rear, the car acts like it's braking on the rear drums instead of biasing things to the front calipers.

Here's my question: According to my shop manual, the brake pedal should only go down "slightly" when the engine is started. For it to drop so far, I wonder if the brake booster is out of whack. Other opinions?

-Bryan

[MrSo0h0o]

how sure are you that it is the rear that is pulsing? pulsing means your rotors are warped.. and since you said u have rear drums, makes me believe your front rotors/pads need changing. how many miles do u have on the car and when was the last time, if any, did you change your rotors/pads?

[reiver62]

I test by pulling the handbrake at 70 mph, and the pulsing was really loud from definately the rear. I could have gotten a bad set of replacement drums I guess.

But what of bothering me more is that I hear the rears pulsing on hard braking. I always thought that rears are not used as much in braking, which makes me think the booster/master cylinder is not biasing things properly.

[CharmCityES]

^ a proportioning valve does the brake biasing.
did you bother to check the front rotors? some odd brake problems can occur and simply be warped front rotors
also, when changing the drums i like to sand the glazing off the shoes, spray the inner drum with brake parts cleaner and use some brake parts lube on the contact points of the shoes to the backing plate....maybe this would help?

[marc780]

One time i was working on a Ford Escort and i did a 4 wheel brake job on it. And no matter how many times i bled the system and adjusted the rear drums the pedal travel was still too far and pedal too soft.

I tried all sorts of things and asked my co workers and even a whole shop full of mechanics could not figure out what to do. Finally out of desperation i replaced the front rotors with new ones, even though they still looked in servicable condition.
changing the rotors fixed the pedal travel problem.