dash brake light on - cold weather

[Guest scubabike420]

My dash brake light sometimes comes on when its cold. Sometimes it will stay on when I start the car and other times it will come on when I've been driving for a little while. The fluid level and the bulbs are OK and the brakes feel fine. The light will eventually go off by itself. Any ideas?

[Legacy777]

Two things cause that brake light to come on. The little sensor in the brake fluid resevoir. If the float in there sticks, you might see some problems or if you have low fluid...which doesn't sound like it.

 

The other reason the light comes on is when you engage the parking brake. It's possible the cable is sticking or something like that....however I would think the on/off switch is inside the cabin and based off of what position the lever is at.....however that may not be right.

 

Lastly....you may have an electrical issue some where.

[Crashton]

Most likely thing would be you are low on brake fluid. As your pads were the brake fluid level drops. The cold weather also makes the fluid contract some.

[GLCraig]

I had this problem a few weeks ago. I ended up opening the mastercylinder and pushing the float up and down a couple of time. I have not had any problems since.

[rcoaster]

I had the same problem with my 96 Outback a while back, when the colder months hit. I checked the parking brake, the fluids, and everything. All checked out okay.

 

By removing the master cylinder cap and replacing it helped the light go out. I also noticed that the rubber thing was fully expanded, leading me to beleive that the rubber thing on the cap was pushing down on the float, causing the sensor to trip. I also noticed that there was a vaccum in the cylinder because I heard an air release when I loosened the cap. The vaccum might have been attributed to the cold weather and caused the rubber thing the expand. Now it has been the coldest it has been and the brake light hasn't come on.

 

RC!

[Guest scubabike420]

I took off the master cylinder cap and put it back on and the brake light went off.

 

Thanks

[mattocs]

In my 5 speed Legacy the parking brake light will come on when its really cold because the brake does not go down all the way...and its also really hard to shift...if I let it warm up, or after a few miles all is well. Only happens when its below 20 deg. or so.

[rallynutdon]

Also tends to happen when the brake fluid is really dirty. When's the last time you changed it?

[Tiny Clark]

I had the rubber expanded on mine, causing the problem.

[SevenSisters]

The rubber bladder keeps moist air from replacing brake fluid in the master cylinder as the pads wear or it leaks out someplace else. If the bladder is extended, you propably also need to top off your fluid.

[Toolbird]

i have a 96 subaru legacy L sedan and its an auto tranny. I started a few days ago with the same problem. my guess its the cold weather codswalloping with my car or its a bad sensor. either way i get the same red brake light and my e brake isn't engaged and my brakes feel stiff at first then they loosen up. i checked the brake fluid and its about half way full but i don't think that would be the cause of the problem. also my Abs light will kick on randomly and the only way to turn that off is to turn off the car and start it back up. any ideas? 

[nipper]

Toolbird. Two things are possible. One is a weak Altanator. The hard brakes is the check valve inside the vac line from the manifold to the master cylinder. it wont be a problem after the car is started and you pump the brakes a few times before you move the car in winter.