Brake light

rungunner · #1 (**permalink**) 05-15-2008, 05:33 PM

Driving down the road the brake light will pop on for a minute and then go off. what do you think would cause this problem? Brakes are new all the way around and work very well. 1997 f-350/ 7.3 diesiel
Thanks

alchymist · #2 (**permalink**) 05-15-2008, 05:38 PM

My guess would be a loose brake switch...if it's a mechanical switch on the brake pedal and it's loose, it can bounce around and activate itself......easy enough to check ...should be mounted next to the brake pedal arm.

projectSHO89 · #3 (**permalink**) 05-15-2008, 06:20 PM

If you are referring to the red BRAKE warning lamp, check your brake fluid level.

If that's okay, the e-brake switch is probably flaky or the e-brake lever is not retracting completely.

Steve

rungunner · #4 (**permalink**) 06-26-2008, 02:47 PM

I replaced both switches and still have the brake light come on. I think something is hanging up in the right rear wheel because after driving for awhile the rim gets hotter than drivers side. I changed the brake caliper on the right side and the drum and shoes are new and everything looks good, I am not sure what is going on but it is driving me nuts. Any suggestions?

Lazy K · #5 (**permalink**) 06-27-2008, 07:51 AM

If your truck has a vacuum brake booster then the vacuum pump may be down a bit. Low vacuum can cause a warning light. If you have hydraboost then I don`t know about it.

rungunner · #6 (**permalink**) 07-18-2008, 02:31 PM

New brakes all the way around.
New drums in the rear.
New switches on both emergency brake and brake pedal.
New ABS switch on the rear differential
New caliper on front drivers side because bleeder would not come loose.
Emergency brakes were partially stuck on so I forced them open due to rusted cables.
The switch on the emergency brake is closed so this can not be the problem.
Now who knows about the booster unit, is there something repairable in that or do I need to replace the entire thing.
The dash brake light still pops on every once in awhile going down the road and now it is really driving me nuts

Lazy K · #7 (**permalink**) 07-18-2008, 03:45 PM

Forget about the booster it is very unlikely to be that. It sounds like you have a wiring connection problem somewhere. Check the electrical connections at the master cylinder. Make sure they are clean and tight. Clean them with contact cleaner if necessary.

rungunner · #8 (**permalink**) 07-18-2008, 04:25 PM

Cleaned all connections with contact cleaner a while back.

Thanks

ynevada · #9 (**permalink**) 07-18-2008, 06:23 PM

check the float in the MC. is it sticking, or down. is the fluid level FULL?

does it ever flash, or just come on? any other lights? abs?
maybe scan it for stored codes?
ive actually seen this before, but never did figure out the problem.

rungunner · #10 (**permalink**) Yesterday, 08:56 AM

I will check the float in the MC.
The fluid level is full.
The light will come on for a minute or so and then go off. The ABS light does not come on.

rebocardo · #11 (**permalink**) Yesterday, 03:28 PM

> I think something is hanging up in the right rear wheel because after driving
> for awhile the rim gets hotter than drivers side.

FWIW: It is more likely you have a leak or something wrong on the side that isn't hot because it is not braking as well as the other side and doing most of the work. I would suspect the drums are not adjusted correctly, especially the cool side.

Try flushing the brake system and especially the ABS. On more then one Ford, the problem has been the screen on the inlet side of the ABS valve has been loaded with gunk. Removed, cleaned, flushed with clean brake fluid, reinstalled, bleed the whole system and no problems.

DO NOT clean the gunk off with compressor air or brake clean. I think the last one I cleaned with carb clean, but, I think just wiping it off and using brake clean should do fine.

> Emergency brakes were partially stuck on so I forced them open due to rusted cables.

Now, what I think could be happening is the hot side might be sticking because the hold down hardware is not overcoming a stuck cable. It drags the shoe, overheats it, then the brake on that side basically does not grab, and causes the ABS to think it has a failure. Pull the code!

On your year, you have to probably disconnect two wires and ground the black/orange side, but, I don't know about 1997. Kind of a cross over year. Go by the repair manual.

If the shoes are sticking on that side and getting hot enough to gas out, then pulling the drum will tell you right away because they will be sort of glazed and have cracks.

I know you have new shoes, but, pull the side that is cool and see if axle fluid has leaked onto the pad. Sometimes on the Dana 60/70/80 you have to replace that metal 8 hole shim.