Brake Warning Light coming on?

[reddahaydn]

Hi All,

i tightened my handbrake on the weekend.

Since then the brake warning light (not the handbrake light) has come on slightly - not full brightness, and a bit on and off for about 30 seconds after I start the car, then it goes off. I have a second gen petrol v6.

i've got plenty of fluid, however ever since I got my rear drums cleaned my rear left drum is leaking some kind of fluid?

Brakes all seems to be working fine. had new pads put in the front when i got the rear drums cleaned.

any thoughts on why the brake light is coming on, or what fluid is leaking?

I also have an intermitant problem. every now and again I get a massive loss of power, just a huge flat spot.
i asked a while ago and i got a lot of responses like change the fuel filter/dizzy cap/rotor etc.
I had previously rebuilt the engine and can confirm that fuel filter, dizzy cap and rotor are all new. new spark plugs. fairly new leads. injectors have been fully serviced and are good to go.

now I think it must be fuel or spark, so maybe the ignition coil? any other suggestions? any thoughts or advice is appreciated.

Cheers in advance,

Haydn

 

[KidVermicious]

Did you overtighten the handbrake? Loosen it a bit and see if the problem goes away.

 

[reddahaydn]

I will try that tonight but it shouldn't be overtight as there is still plenty of clicks before it comes on.

 

[KidVermicious]

There's only two fluids that can show up at the rear drum, gear oil from the axle or brake fluid from the brakes. Brake fluid has a distinct feel to it when you rub it between your fingers, so that's how to tell what's leaking back there. My money is on brake fluid, since you were just working back there.

If your warning light isn't an overtight ebrake cable that thinks its on, it's probably your brake fluid level.

 

[reddahaydn]

Hey mate,
Well I loosened the handbrake and it seemed to fix it till tonight. It also has plenty of brake fluid in the reservoir so it's got me stuffed.

I gave the leak a proper wash and it doesn't look as bad as I thought but it might be gear oil. Would that be an issue on my brakes?

 

[KidVermicious]

Hey mate,
Well I loosened the handbrake and it seemed to fix it till tonight. It also has plenty of brake fluid in the reservoir so it's got me stuffed.

I gave the leak a proper wash and it doesn't look as bad as I thought but it might be gear oil. Would that be an issue on my brakes?

If your axle seals are leaking that could easily be gear oil, and if it gets in the drums thats certainly an issue. It shouldn't cause a warning light, though, the truck ain't that smart.

Check and see if your brake fluid sensor is malfunctioning, maybe? I'm not sure what else would cause it to throw a warning light, if it's not the ebrake and it's not the level...

 

[awbartley]

Smell it, youll know if it is gear oil....it stinks bad.

 

[fourwd1]

I gave the leak a proper wash and it doesn't look as bad as I thought but it might be gear oil. Would that be an issue on my brakes?

Yeah, gear oil or brake fluid getting on the shoes creates a stopping issue.

 

[reddahaydn]

OK, so after spending $680 yesterday getting rear shoes, machined drums, new wheel bearings and seals (it was gear oil leaking) and all the rear brakes adjusted up properly, my brake warning light is still coming on.

My front brakes had new pads and a full adjustment a few months ago.

It must be the brake fluid sensor, but how do I check if this is malfunctioning? Is there a sender or the reserviour that could be loose? (I remember an engine warning light on my old car was a loose sender). Or is it likely to be the float itself?

It's just wierd that it started straight after I adjusted the handbrake, but didn't go away when the rear brakes have all been adjusted properly with new pads.

Any thoughts on how to test the brake fluid sensor?

Cheers

 

[KidVermicious]

Any thoughts on how to test the brake fluid sensor?

Cheers

Do you have a DMM? The sensor just has two wires coming off the top of the master cylinder and a connector right there, it shouldn't be too hard to figure out what signal it's sending when the light is on, and if that signal is different when the light is off and the fluid level didn't change then you know you've got a flaky sender. Or just swap out that sensor, cap and all. They can't be too spendy.

Just to be clear, though, your fluid level is definitely high, right? My brake light will come on when the fluid is right at the fill line - I have to give it a couple extra glugs to get it to shut up.

 

[Gerdo]

As far as I know, there are only two things that make the light come on. The brake fluid level float and a switch on the hand brake lever.

My guess is that they are both normally open and close when you have low fluid or raise the brake lever making contact and lighting the light.

 

[illzoni]

Wasn't there another recent thread about that light coming on when the alternator was overcharging the system?

 

[Idrv2yotas]

Is the light coming on when you step on the brake, if so then there is an internal leak in the master cylinder.