yact: Brake warning light appears when i brake semi-hard

[JEDI]

i have a 2001 chevy prizm.

i have driven 65k miles so far, but have never braked hard before. that is till yesterday. the light turned yellow and i noticed a cop at the opposing intersection. i was at the 50/50 point, and decided to brake instead of speed up.

it wasn't that hard of a brake..no junk went flying off the seats to the floor. but it was the hardest i've ever braked in this car. i noticed that the brake light inidcator on my dash lit up when i did that then went away a couple of seconds later.

normal braking was still fine..no lights. i went to a parking lot and braked semi-hard to see if it was a one time thing. nope..tyhe brake light came on again, then went away. normal braking is still fine.

Is this normal? if so, why does the light come on?

edit: i do not have ABS brakes

 

[tweakmm]

I can only imagine that since the break light came on something is wrong with your breaks.

 

[ohtwell]

Have you checked the brake fluid level? You might be low.


: ) Amanda

 

[The Stigenator]

fluid level in the master cylinder..

 

[Heisenberg]

Yeah, first thing is check the fluid level. Did the ABS kick in when you stopped?

 

[FoBoT]

Originally posted by: ohtwell
Have you checked the brake fluid level? You might be low.

:thumbsup:

 

[Merlyn3D]

Happened to me a couple months ago, go pick up some brake fluid (they even have it at safeway) and add it (unless it's full already). If that don't fix it take it to a brake mechanic you trust. (For me, I trust my local goodyear gemini service center, never fails they always give me the lowest quotes of any of the mechanics in my city)

 

[Pepsi90919]

is that normal? i dunno, do you think a red light on your dash that says "BRAKE (!)(P)" is normal?

 

[wfn]

things you might need to do (in order of suckiness):

1. replenish brake fluid
2. check the e-brake / sensor for e-brake release
3. have your brakes pumped
4. replace master cylider

 

[Fingers]

check brake fluid

 

Brake fluid, probably time to bleed the system, and check the hoses.

 

[OS]

Originally posted by: ohtwell
Have you checked the brake fluid level? You might be low.

: ) Amanda

damn, aren't you a chick, how the hell do you know that.


Anyways, I used to have a 2000 prizm. It usually happened when the brake pads were pretty worn, and a quick fix is to add more brake fluid like everyone said already.

 

[DrPizza]

wait a second... check the brake fluid and simply top it off?! It's normal for your fluid level to go down as your pads and/or shoes wear. But, it shouldn't be going down to the point of having the brake light come on. Most of the time, you start with new pads and a full reservoir, then, when the pads need to be changed, the reservoir will still be full enough (but not at its original level.) Then, after the pads are replaced, the fluid level in the reservoir will be back up to full, since the calipers will be pushed back in further.

Now... if you need to add fluid because the light is coming on... most likely there's another problem CAUSING the fluid level to be low. The stuff doesn't just evaporate away or disappear into another dimension. It's possible that you have a leaking brake cylinder or something. Not a huge problem - not difficult to fix, but definitely a dangerous enough condition that simply topping off the brake fluid so the light doesn't come on again this week is going to fix.

If you don't know enough about brakes - take it to a mechanic you trust.
edit: because most places, ie midas, monroe, will be more than happy to take your money to fix problems that don't exist.

 

[ohtwell]

Originally posted by: OS

Originally posted by: ohtwell
Have you checked the brake fluid level? You might be low.

: ) Amanda

damn, aren't you a chick, how the hell do you know that.


Anyways, I used to have a 2000 prizm. It usually happened when the brake pads were pretty worn, and a quick fix is to add more brake fluid like everyone said already.

Anyone should know that anytime a warning light like that comes on, the first thing to do is to check the fluid level.


: ) Amanda

 

[ohtwell]

I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

 

[AlienCraft]

Originally posted by: ohtwell
Have you checked the brake fluid level? You might be low.


: ) Amanda

Winnah!
Check fluid level. Top off with fresh fluid

 

[Zenmervolt]

Originally posted by: ohtwell
I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

If the brake fluid is low enough to trigger the warning light, then either the pads are worn well past the minimum, or there has been excess fluid loss.

The brakes are a _sealed_ system, so the fluid should never be low enough to trigger the light unless there is a problem in the system.

ZV

 

[Nebor]

Looks like everyone beat me to the brake fluid solution.

I had the same problem in my Volvo 960 once. I noticed the brake light came on when I was sliding sideways, or doing any aggressive cornering. I thought maybe it was the cars way of telling me to slow down, or warning me that something might "break" if I kept it up. Eventually it got to where if I would burn out out or hard launch from a stop, the "Brake" light would come on. Frankly, I was baffled, how could hard acceleration trigger the brake light?!

So I take it into Volvo and explain things, and they are also stumped. Out of desperation, I asked some guys at the local auto parts store, and they said, 'Well, sounds like your brake fluid is low.' It just hadn't occured to me. So I bought some DOT 4 and went out there, and sure enough, the fluid was just at the minimum mark, so that anything that would cause it to "slosh" around in there would trigger the low fluid sensor.

Good story huh guys?

 

[ohtwell]

Originally posted by: Zenmervolt

Originally posted by: ohtwell
I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

If the brake fluid is low enough to trigger the warning light, then either the pads are worn well past the minimum, or there has been excess fluid loss.

The brakes are a _sealed_ system, so the fluid should never be low enough to trigger the light unless there is a problem in the system.

ZV

Well, I did say that I wasn't sure there wasn't leak.


: ) Amanda

 

[Nebor]

Originally posted by: Zenmervolt

Originally posted by: ohtwell
I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

If the brake fluid is low enough to trigger the warning light, then either the pads are worn well past the minimum, or there has been excess fluid loss.

The brakes are a _sealed_ system, so the fluid should never be low enough to trigger the light unless there is a problem in the system.

ZV

How do you know his pads aren't 3 inches thick? How do you know the diameter of his brake lines? There's a lot of varying factors here that could change how much brakefluid is used as the pads wear and the calipers compress.

 

[Pepsi90919]

Originally posted by: Nebor

Originally posted by: Zenmervolt

Originally posted by: ohtwell
I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

If the brake fluid is low enough to trigger the warning light, then either the pads are worn well past the minimum, or there has been excess fluid loss.

The brakes are a _sealed_ system, so the fluid should never be low enough to trigger the light unless there is a problem in the system.

ZV

How do you know his pads aren't 3 inches thick? How do you know the diameter of his brake lines? There's a lot of varying factors here that could change how much brakefluid is used as the pads wear and the calipers compress.

oh really, what chevy prizm out there uses 3 inch pads?

 

[Zenmervolt]

Originally posted by: Nebor

Originally posted by: Zenmervolt

Originally posted by: ohtwell
I don't think there has to be a leak for him to be low on brake fluid. I'm not saying there's not, but I wouldn't automatically jump to the conclusion that he has a leak somewhere. If he's low, he should add some, then check it about a week later. If he has lost a considerable amount, then he should start looking for a leak.


: ) Amanda

If the brake fluid is low enough to trigger the warning light, then either the pads are worn well past the minimum, or there has been excess fluid loss.

The brakes are a _sealed_ system, so the fluid should never be low enough to trigger the light unless there is a problem in the system.

ZV

How do you know his pads aren't 3 inches thick? How do you know the diameter of his brake lines? There's a lot of varying factors here that could change how much brakefluid is used as the pads wear and the calipers compress.

Yes, and _all_ of those variables will be taken into account by the factory when they place the fluid level warning sensor.

No company would place the warning sensor anywhere near a point where the fluid level would be during normal operation.

I repeat, if the light is being triggered, then the fluid level is well below the design minimum and there is something else wrong with the system. No properly-functioning braking system will ever trigger the light. Either the pads are worn well past spec to where they are allowing the pistons to extend too far, or there is a leak somewhere that needs to be fixed. The first is highly unlikely because in order for the pistons to move that far, the pads would have to be worn to the metal backing plates which would render the brakes essentially non-functional (and really loud).

How do I know these things? I've worked on more than one car and I have basic thinking skills as well as a knowledge of design principles.

ZV

 

[OS]

Originally posted by: Zenmervolt
Yes, and _all_ of those variables will be taken into account by the factory when they place the fluid level warning sensor.

No company would place the warning sensor anywhere near a point where the fluid level would be during normal operation.

I repeat, if the light is being triggered, then the fluid level is well below the design minimum and there is something else wrong with the system. No properly-functioning braking system will ever trigger the light. Either the pads are worn well past spec to where they are allowing the pistons to extend too far, or there is a leak somewhere that needs to be fixed. The first is highly unlikely because in order for the pistons to move that far, the pads would have to be worn to the metal backing plates which would render the brakes essentially non-functional (and really loud).

How do I know these things? I've worked on more than one car and I have basic thinking skills as well as a knowledge of design principles.

ZV

I used to own that car, there's probably nothing wrong with the brake system otherwise. Like I said, the same thing happened on my car and although the pads were worn, they were still usable for several thousand miles. He just needs to top off the fluid.

 

[Nebor]

Originally posted by: OS

Originally posted by: Zenmervolt
Yes, and _all_ of those variables will be taken into account by the factory when they place the fluid level warning sensor.

No company would place the warning sensor anywhere near a point where the fluid level would be during normal operation.

I repeat, if the light is being triggered, then the fluid level is well below the design minimum and there is something else wrong with the system. No properly-functioning braking system will ever trigger the light. Either the pads are worn well past spec to where they are allowing the pistons to extend too far, or there is a leak somewhere that needs to be fixed. The first is highly unlikely because in order for the pistons to move that far, the pads would have to be worn to the metal backing plates which would render the brakes essentially non-functional (and really loud).

How do I know these things? I've worked on more than one car and I have basic thinking skills as well as a knowledge of design principles.

ZV

I used to own that car, there's probably nothing wrong with the brake system otherwise. Like I said, the same thing happened on my car and although the pads were worn, they were still usable for several thousand miles. He just needs to top off the fluid.

Can I get a "pwned" pic?

No hard feelings Z, we can't all be right all the time.

 

[JEDI]

i don't have abs.

i thought when brake pads were running low that you hear the whisling? anyway, 4 months ago when i went for yearly inspection, the guy said my brake pads were 6/10 on a scale of 1-10. and i've only driven a few thousand miles since then w/no hard stopping (except this one time) or riding on the brake.