Brake light on dash???

KYJeepMan1 · 02-16-2011, 02:33 PM

Today i went for a short drive and noticed that the Brake light on the dash cluster was on. I use my parking brake all the time and i've never seen this light on before. My parking brake does not seem to be stuck on, because i can move the jeep with my foot. But my brake pedel does go to the floor some times now. When i bought the jeep a week ago i noticed that the brake pedel had alot of travel. Now there seems to be a problem. Any advice??? What to do next???
Thanks

aldrichg9 · 02-16-2011, 02:41 PM

My back brake line is broken and leaked all the fluid out causing the light to come one.

This is not only the parking brake light - its the brake system warning light as well.

Check your fluids first and check for leaks.

I'd say with lots of pedal travel you have a leak and/or lots of air in a line somewhere

rdsk8ter · 02-16-2011, 02:44 PM

low fluid will do that too refill and check all hoses

KYJeepMan1 · 02-16-2011, 02:51 PM

The fluid level is fine, and i don't see a leak at any of the wheels. Maybe i should try to bleed the system first. Is there any speical order to bleed the brakes?
Also the light has never come on as i use the parking brake everyday. That seems odd to me that it has never worked until today. It should come on when the parking brake is on.

The Haynes manual says it will stay on until the system is repaired.

SPCMilligan87 · 02-16-2011, 02:58 PM

Bleed the Brakes really REALLY good! Then disconnect the battery and your problem should be solved. If your pads are too worn the light will come on also but it sounds like you have air in those lines.

SPCMilligan87 · 02-16-2011, 03:01 PM

Bleed the brakes Pas rear, driver rear, pas front, driver front. farthest from master cyl to closest

KYJeepMan1 · 02-16-2011, 03:14 PM

Ok Thanks for the help. I'll start there.

**Mean Max** · 02-16-2011, 04:09 PM

Quote:

Originally Posted by SPCMilligan87

Bleed the Brakes really REALLY good! Then disconnect the battery and your problem should be solved. If your pads are too worn the light will come on also but it sounds like you have air in those lines.

Not completely accurate.

Yes, bleed the brakes really good to start with. But I'll bet you're having an issue with a leak. If your fluid level does not deplete, you probably have a bad master cylinder. The light on the dash will only come on from 1 of 2 switches. Either the parking brake switch, or the proportioning valve switch. Unhooking the battery will not affect anything & would be a waste of time. Brake pad thickness will not cause the light to come on, there are no pad thickness sensors.

Most likely, your master cylinder is leaking internally, or into the power brake booster.

Max

Sent from my HTC Incredible Droid

GA05SPORT · 02-16-2011, 06:32 PM

On my Jeep that I just picked up I curiously removed the piece of tape covering a section of the warning lights in the dash. It revealed a lit BRAKE indicator. Looking at the back of the parking brake I discovered that the "plunger" portion of the parking brake switch was seriously messed up. Disconnected the wiring tagged it and tuck it away. Presto, BRAKE indicator out.

GaJeepy · 02-16-2011, 06:39 PM

Quote:

Originally Posted by Mean Max

Not completely accurate.

Yes, bleed the brakes really good to start with. But I'll bet you're having an issue with a leak. If your fluid level does not deplete, you probably have a bad master cylinder. The light on the dash will only come on from 1 of 2 switches. Either the parking brake switch, or the proportioning valve switch. Unhooking the battery will not affect anything & would be a waste of time. Brake pad thickness will not cause the light to come on, there are no pad thickness sensors.

Most likely, your master cylinder is leaking internally, or into the power brake booster.

Max

Sent from my HTC Incredible Droid

After having a terrible brake problem and fixing everything my dash light was still on. My step dad, a retired mechanic for the air force told me to crank my jeep and mash the brake pedal as hard as possible. This made my light go off. I'm just wondering if you have ever heard of this or tried it?

**Mean Max** · 02-16-2011, 06:47 PM

Yes, I have heard of that. That's the "old school" way of balancing the proportioning valve.

When there's a fluid pressure issue, the spool valve gets off balance & stays in one end of the valve body. Massive pedal pressure helps it re-center in the body which allows the light to stay off.

Max

Sent from my HTC Incredible Droid

GaJeepy · 02-16-2011, 07:02 PM

Quote:

Originally Posted by Mean Max

Yes, I have heard of that. That's the "old school" way of balancing the proportioning valve.

When there's a fluid pressure issue, the spool valve gets off balance & stays in one end of the valve body. Massive pedal pressure helps it re-center in the body which allows the light to stay off.

Max

Sent from my HTC Incredible Droid

That's pretty much how my step dad explained it. I couldn't think of the name of the valve. Always enjoy your posts.

KYJeepMan1 · 02-16-2011, 07:06 PM

I unpluged the proportioning valve switch under the master cylinder and the light went out. So i will have to bleed them tomorrow. Also i'll check each wheel for a leak.

KYJeepMan1 · 02-17-2011, 10:20 AM

UPDATE: I took the Jeep to a shop and they tryed to bleed the system. They could not get a drop of fluid out of the lines. So he tryed at the master cylinder and still no fluid. They replaced the master cylinder and now the brakes are good as new. BUT the light is still on. They said it was the switch under the master cylinder would not reset. Can you quys give me any advice on what to do now. Can the valve with the switch be takein apart and repaired or replaced?
Thanks...

**Que89YJ** · 02-17-2011, 10:27 AM

I would take the jeep back to them. You paid to have it repaired and the light on is not repaired.