View Full Version : {BRAKES}Brake warning lamp

09-24-2004, 11:44 AM
Is the brake indicator light on the dash (same one that's on for parking brake) going to turn on if there is a power brake booster failure?

I was driving to school today, I think my brake booster is working intermittantly. The times it doesn't, it doesn't take much brake force before the light comes on. I know it comes on if there is a leak somewhere, since the proportioning valve would be way out of whack... but I haven't seen any leaks yet, and my brake fluid reseviours are holding steady.


09-24-2004, 12:13 PM
It comes on when there is difference in pressure between the front and rear brake lines. The switch is located in the proportioning valve. Are you losing fluid.

09-24-2004, 03:13 PM
No, I'm not loosing fluid, as far as I can tell:

...and my brake fluid reseviours are holding steady...

If the only way it will come on (other than parking brake set) is because of the proportioning valve... could it be croaking? I've never heard of that happening before.

Like I said before, it's INTERMITTANT. One time I brake, it feels like my power brake booster is not there, and the light comes on. I can let off all the way and immediatly brake again, and it feels fine, brakes fine, and the light doesn't come on.

So maybe I have more than one problem on my hands here.

I guess I'm going to drive the rice burner to work today. :poop2:

09-24-2004, 08:48 PM
brake warning light has nothing to do with the power booster. If the warning light is coming on, you either have a loss of fluid or loss of pressure. Inspect for leaks, then replace the master cylinder.
If the booster is bad, replace them as a unit.... much eaiser and in some cases cheaper.

09-24-2004, 09:11 PM
If my master cylinder is dead.... I shall be highly irritated, as I just replaced it in January this year. Power brake booster was replaced sometime within the year before that. Master cylinder was actually pretty inexpensive, but I think it's still under warrenty.

Anyone have a ballpark figure on the price of a proportioning valve?

Oh well. Brake system is getting fine-tooth combed tomorrow, it looks like.

09-28-2004, 03:27 PM
when my booster and master cylinder failed it took 2 weeks and 5 of each part to get it right. They explained that the car was so old the replacement parts sit on the shelves for so long the rubber in them dry rots. When the damaged unit is put on it quickly shows its fault. The shop that handled my repair spent a TON of money fixing it..along the way (not believing they could have gotten 4 bad boosters in a row) they replaced my rear wheel cylinders, rear brake pads, and some other parts. It was crazy how long it took.

09-28-2004, 10:21 PM
Well, I think this car has had at least 6 or 7 power brake boosters, and somewhere arround the same number of master cylinders. Just a year or two ago, though, I changed the factory wheel cylinders. I can't beleive they lasted that long. My rear brakes have never given me much trouble, except for when I let the fluid level get too low. Which is my own fault. :cuss:

I've had a few calipers lock up on me, worn some groves in the rotors.... but the main brake issues I have is the blasted master cylinder and PBB.

Anyway, I changed the hose to the booster, that one had been on there for lonnnnnng before I ever drove the car. Didn't bleed anything, and the brake warning lamp hasn't come on since sunday, even if I stand on the brakes pretty hard. And I've had at least 3 jackasses pull in front of me since saturday, and I had to lock up at least my front wheels from stomping so hard on the pedal. So it seems my brakes are suddenly cured.

I also read in the manual something about bleeding the 3-way valve? I've never done that before... :dunno:

Oh well. Thanks for the suggestions anyway. I'd rather change a brake booster than a master cylinder.

10-15-2004, 11:29 AM
Alright, ever since the last post, my brakes have been working just fine.

THen today, same thing happened again.

Here's the odd thing: (don't laugh at the story) Last time this happened, I was feeding a friend's dogs on the other side of town. He has a reaaaaaaaaly steep driveway. Whenever I left his house was when I would notice the brake issue. Well, whenever I quit going over to his house last time, I stopped having the problem. That was probably 5 or 6 weeks ago. Not a problem since. THen today, when I left his steep drive way, IT HAPPENED AGAIN!!!!!!!!!!

Does this say internal master cylinder leak to anyone? The fluid level has been holding within an 8th of an inch from the top of each resevoir. I checked right after It happened today, still up at the top. NO signs of leaks. Just a brake warning lamp on braking... unless I lift the pedal up, and press right again, and it works fine.

:chainsaw: What would a steep hill do to my brake system? :cuss: :cuss: :cuss: :cuss: :cuss:

10-15-2004, 12:01 PM
thats fucked up.

10-16-2004, 12:37 AM
Yeaaaaaaaaaaaaaah......... sure is.

So any ideas?