Just trying to track down some possibilities of the cause of this here is the scenario

1 Happens in cool weather < 60 degrees
2 Brake Light turns on on the console
3 Brake hard and the light turns off
4 Continue driving...sometimes it comes back on...sometimes not...less likely after driving for a little bit

Thoughts? My first guess would be a fluid swap maybe a little bit of moisture in the fluid?

Thanks

 

Does the ABS light come on along with the brake light ever?
Check the handbrake, it might be the sensor that responsible for telling you that you got the handbrake up.

 

Same problem and it only happens when its cold. I put my e brake down but the brake light still lights up. I dont think my rear brakes are dragging though.

 

Check the brake fluid level. As your breaks wear, the level in the reservoir will go down. This is a normal thing. There is a sensor for low brake fluid and the level is probably pretty close to where the light will soon be on all the time. In the cooler temperatures the vluid contracts and the light come on. When the engine heat warms it up, the fluid expands and the light goes off.

 

^^ + 1..i was think the same thing..check your break fluid

 

I will double check the brake fluid but last time I checked when it happened was halfway.

L36 - The ABS light has never come on

I just might replace the brake fluid while I'm at it hmmm

 

Hey There! Sorry to impose on your thread by I cannot start a new one yet. I have a quick question. A shop replaced my tie rod 2 weeks ago. After the fix I started having steering issues. Now they say I need my control arms replaced for $872! Could they have missed the control arms issue while replacing a tie rod?!?! I just can't believe they could have missed this problem. Please help. Thanks.

 

Probably brakes as they wear the fluid level goes down. I have heard not to add fluid, but just change the brakes.

 

automatic or manual tranny?

Does the ABS come on at the same time?

Does the battery light ever come on?

Sounds like low fluid, a bad sensor, or a poor connection to one of the components that is causing insufficient voltage.

 

your low fluid sensor won't set off until the reservoir is out of fluid or very close to it, so unless the resevoir is pretty much empty, that's not likely the problem.

Does your car HAVE ABS?

 

it's an automatic with ABS

i braked hard to trigger the ABS and that was working....and turned the brake light off at the same time

the pads have plenty of meat left on them

Battery light has never gone off

Tuner- do you mean the sensor in the resevoir?

What other sensors trigger off the brake light? anything from the master Cylinder?

 

There is a white styrofoam-like plastic float in the master cylinder brake fluid reservoir. You can't see it that easily because of the filter screen that is in the filler opening. But when the brake fluid level gets low, the float sinks lower and operates a switch. If you look on the side of the master cylinder towards the center of the car, you will see an electrical plug with 2 wires in it. If you want to, as a test, unplug this wire and you won't get the brake light on the dash if the master cylinder is causing it. Another test you can do is to fill the brake fluid reservoir to the MAX line and see what happens.

 

This is fantastic advice. Admittedly I didn't know there was a float in there though. Sounds like this may be your culprit.

I will say though, I personally never advise someone to top up or fill the brake fluid. Unless you've recently changed a caliper or some other component of the hydraulic system. A properly functioning brake system should never need a top up.

 

As the brake pads wear, the caliper piston doesn't retract back into the caliper cylinder as far. This extra space in the cylinder is then filled by brake fluid from the master cylinder. If the master cylinder wasn't completely filled to start with, you can get the brake warning light. This is more common when the car has had several brake jobs and the fluid level was not checked.

A situation that people who do brake jobs need to pay attention to is to check the fluid level in the master cylinder BEFORE you start the brake job. If the master cylinder had been filled to the MAX line, you will have brake fluid over flowing the master cylinder. When you push or screw the piston back into the wheel cylinder, this will push the extra fluid back up into the master cylinder.

 

I added some more brake fluid last night and no brake light this morning and it was very cool outside this morning....

Before it was never below the MIN line prob a little bit below halfway so I filled it to the max line. But i will see what happens over the next few days to see if that cures the issue. If not I'll unplug the wire

DennisMiK - is the parking brake and the resevoir the only 2 that trip off the light?

 

By itself, yes. But it will also come on with the battery light which means the alternator is bad.

 

Well said. Although keep in mind, like I said, unless there is a brake line, master cylinder, caliper or something of the like replaced, the level should never need to be touched. Changing brakes should only change where the fluid is (calipers, lines, reservoir) in the hydraulic system, it should not actually change the amount of fluid in the system.
(I know you know this Dennis I was just clarifying for others)