Why would my breaks quit working on a 99 Chevy Silverado?

Question

I left work this evening and everything was fine. I made a stop and when I started the truck back up and stopped at the first stop sign, my breaks were not working for the most part. I was able to get stopped, but it feels like there is air in the lines and I have to "floor" the breaks. I checked the fluid and it is fine. Why would they stop working just like that?

Answer 1

Your problem is most likely your master cylinder or your power assist, if your fluid is good.

Here are the basics of how brakes work: You have brake pads on each wheel that clamp down on a disk (or shoes that rub on the inside of a drum) and these are actuated by an hydraulic piston. On disk brakes the hydraulic piston on each wheel is contained in the caliper assembly. On drum brakes there is a wheel cylinder. In either case, the hydraulic cylinder on the wheel is smaller than the one in the master cylinder which is activated when you press down the brake pedal. The differential in size of the pistons essentially provides your foot with a multiplier of force. Now, add to this a power assist of some sort, either from a vacuum assist or an actual pump and when you press down on the brake pedal it also opens a valve to give you even more of a multiplier effect. This is why when your engine dies you find it much harder to stop, as you are getting no power assist. In your case, I would guess that either the power assist, be it pump or vacuum is not working properly, or the master cylinder itself has partially failed in some way.

As to the one fellow who mentioned the possibility of an anti-lock brake system failure, I suppose anything is possible, depending upon the design of the system, but that seems unlikely to me. Generally speaking, the antilock system is set up in such a way that a computer is able to read each wheel's turning speed and compares it to the car's speed. If the turning speed of a wheel is very slow or stopped entirely and the car is moving, then the computer knows that the wheel has locked up in a skid, and it takes control of the brake and pulses the brake on and off in an attempt to interrupt the skid. Most anti-lock systems with which I am familiar have a failsafe mode. If the ABS is not working, the computer shuts the system down, and the brakes continue to operate, but no longer with the anti-lock feature available. Accordingly, I would be a little surprised if an ABS failure affected your braking capacity under normal operating circumstance. That system really only comes into play in an emergency stop.

Answer 2

They've had problems with the ABS system. It's probably under the cab directly below the driver's seat. They had a recall on some for a wiring harness. Bottom line.....computers don't belong in cars unless the engineers can get it right!!

Answer 3

1st things first if your breaks feel spoungy it could be a bad seal in your master cyl. also if you have to floor your breaks to stop i would stop driving it for you can kill yourself. take it to a pro and have your brakes check it could be dangerous otherwise.a problem like you have can be one of many things wrong with your brake system and requires immediate attention.

Answer 4

Most likely, there is air in your brake lines. contact a qualifiied technician for a full evaluation of you braking system. It is possible that your master cylinder is bypassing internally.

Answer 5

When was the last time you replaced the break pads? Also, could your tires be low?

Answer 6

basically the a million no longer working? it may desire to be a bad socket or that black cord on the socket isn't making touch. that black cord is the floor. nevertheless blinks yet quickly could desire to intend the bulb is able to blow.