First time for everything: "Brake Failure" light O

[hrstudioplus]

Does the light activate based on fluid levels? All of a sudden my front left brake is squealing, so I'm assuming I need new pads, but my main question is what exactly triggers the light to turn on?

PS, BMW designed this light to be super emphasized, super bright red, and super annoying, so I'm assuming it's super urgent, ha.

Hassan

[jrhone]

Others may chime in, but its definitely based in part on fluid level...check your brake fluid level. Some cars have sensors to go off when the pads get low, I doubt the 02s have them...Its probably low fluid, but is it due to the pads getting so low that the pistons in the calipers are pushed too far out and the fluid is getting out that way? If its low, fill it and look for the leak. If you cant find it, the clutch master cylinder also leaks and in that case it'll be in your pedal box...

[Napes]

At least on square-lite cars the brake warning light will come on for either;

1) Low brake fluid, or 2) the hand brake is on.

Someone else will have to chime in on the roundies.

Bob Napier

[MMII73]

What year is your car?

It can also be a low fuel warning.

'76 (only) also has a super secret reset button that is nearly invisible and can only be reached with a tiny screwdriver or similar device.

Usually it's low fluid level.

[c.d.iesel]

YES IT IS SUPER URGENT!

DO NOT DRIVE THE CAR UNTILL

you have removed the wheels

and inspected the brakes!

pads worn to metal?, caliper pistons stuck?,

broken pad retaining spring? LOOK today

before killing yerself!

report back with photos if nec. so we can advise

................. yea, " ha " indeed!

[2ma2]

There is power to the bulb always,this circuit has 2 ground points, either will complete the circuit and cause the light to glow. One ground is in the resevoir cap so check the fluid level first, If it ok check the other grounding point which is a little switch on the rear of the parking brake arm under the rubber cover. If both of these check out ok then you have a wire going to ground before it reaches the switch

[bluedevils]

also check hand brake switch under the rubber boot, sometimes they short out, or cable came loose touching the ground causing the light to come on.

[gwb72tii]

also check hand brake switch under the rubber boot, sometimes they short out, or cable came loose touching the ground causing the light to come on.

for sure the light has nothing to do with the condition of your brakes or brake system

in my 72tii it is only for fluid level in the reservoir

[bluedevils]

On my 74 tii, the light comes on if the hand brake switch is shorted, don't know about early cars like yours, in my case IT IS A FACT that it is both related to hand brake as well as other brake stuff, and I have no brake failure despite the light is on all the time due to bad switch, clear?

[hrstudioplus]

Ok so my computer is dead with no charger, doing this on my iPhone. I checked my brake fluid levels and realized it was about halfway, filled it back, and the light turned off. I drove to my mechanic's house this morning for good measure.

We take off the front wheels and everything seems fine, mayne just need a little sanding on the rotor surface because the circular grooves seemed to be causing the loud squeal. So front = all good.

Take off the back wheel and he couldn't even pull the circular drum off from around the brakes (sorry if that's not the part name, noob here obviously). Finally pull it off and there is debris everywhere, so my back brake was pretty much stuck open. I hop in the car to pump the brake a few times while the wheel was off, and we realize that the fluid was sending, but not returning (the brake hardly would return back to the position it should be in during driving). So this might be a master cylinder problem, or a rear wheel cylinder problem. He's gonna do a few more tests to see.

While the car was jacked up we decided to hop under for good measure and saw that my slave cylinder was completely inflated and buldging full of fluid! So obviously this light was more than a fluid level warning for me and I'm glad I acknowledged it completely.

Everything is getting worked on right now (new master cyclinder and/or rear wheel cylinders, new slave cylinder, rear brake shoes, rotor sanding) and I should be back on the road by Tuesday. Thanks for everyone's help.

Hassan

[BillWilliams]

You may think about new flex lines too - bad flex lines is a common cause for "brakes not returning"

[jgerock]

You may think about new flex lines too - bad flex lines is a common cause for "brakes not returning"

+1. Sounds like your complete hydraulic system (brakes and clutch) needs to be gone thru. Once you have the system "opened", you might as well replace the parts now before you have an accident due to faulty brakes. That BIG red light on the dash is important.

[gwb72tii]

Ok so my computer is dead with no charger, doing this on my iPhone. I checked my brake fluid levels and realized it was about halfway, filled it back, and the light turned off. I drove to my mechanic's house this morning for good measure.

We take off the front wheels and everything seems fine, mayne just need a little sanding on the rotor surface because the circular grooves seemed to be causing the loud squeal. So front = all good.

Take off the back wheel and he couldn't even pull the circular drum off from around the brakes (sorry if that's not the part name, noob here obviously). Finally pull it off and there is debris everywhere, so my back brake was pretty much stuck open. I hop in the car to pump the brake a few times while the wheel was off, and we realize that the fluid was sending, but not returning (the brake hardly would return back to the position it should be in during driving). So this might be a master cylinder problem, or a rear wheel cylinder problem. He's gonna do a few more tests to see.

While the car was jacked up we decided to hop under for good measure and saw that my slave cylinder was completely inflated and buldging full of fluid! So obviously this light was more than a fluid level warning for me and I'm glad I acknowledged it completely.

Everything is getting worked on right now (new master cyclinder and/or rear wheel cylinders, new slave cylinder, rear brake shoes, rotor sanding) and I should be back on the road by Tuesday. Thanks for everyone's help.

Hassan

welcome to 2002 restoration