Brake pedal occasionally goes down low

Chrysler Sebring Convertible JXi 1998, 105K

Occasionally the brake pedal goes down substantially further than normal. If I bring it back up and press it again, it’s fine. When it happens, it doesn’t go all the way to the floor, and the brakes still work, but it’s worrying.

I’ve had the system bled twice, once by the brake place, once by the dealer. I’ve also had a new master cylinder installed. It still does it. What else could it be?

This is pretty much a classic master cylinder failure symptom. There’s not really anything else that can cause this.

Does your dashboard brake lamp light when it does this?

Has anyone checked the rear brakes? Problems in rear drum brakes and/or park brake cables (worn out or out of adjustment) can mimic a faulty master cylinder.

mmm. they put a brand new master cylinder in already, and it made no difference.

Nope, dashboard light doesn’t come on.

Possibly not - I took it into the dealer (in desperation), and you’d think for the amount they charged they’d have checked everything out, but maybe not. I’ll phone and ask what they checked I guess … thanks very much for the suggestion.

Any check regarding brakes should check out the entire brake system, but I mean you don’t take apart the whole system and put it back together! However you don’t; for example; just look at the front brakes and not the rear, or something like that. Ask them what the measurements of the linings were- all 4. Did they find seeping wheel cylinders, or calipers? Ask what they experienced on the

road test. If they say they didn’t road test car, say, "Wait a minute- I brought my car in with a safety related brake complaint and you didn’t road test the car? Ask what they thought about the condition, adjustment, and operation of the parking brakes. I’m telling you, don’t be shy about this stuff, cause they should be able to answer all these questions. One time I was on the

interstate for maybe an hour solid cruising at a steady speed. I had a front wheeel vibration, but not severe. I applied brakes as I entered exit ramp, and pedal went to the floor. Then it was ok. The vibrations over the previous hour had caused one of the front brake caliper pistons to "walk’ back into its bore, forcing me to use much more pedal travel than usual; so there wasn’t anything

really wrong w/my brakes. Poss. this could fit your scenerio? Have them, w/engine off, push brake pedal a few times to get rid of all the boost. Pedal should become harder to push. Then they push and hold pedal down hard- it should be “rock hard”. (You can do this yourself, too.) If not, there may still be air in system. after mast cyl was replaced they may have bled all 4 wheels,

which is hard on some ABS cars. Do you have ABS? There still could be air in system. Post back after discussing these isssues w/dealer.