BRAKES!!!!! Darn Light?!?
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Freshman User
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BRAKES!!!!! Darn Light?!?
ok, this evening i went over to my Brothers house and when i pulled in his drive my Brake light came on. that has NEVER happened before. I checked the fluid level and it is fine up to were it is suppose to be. though i did just for curiosity checked the lines and the whell cyliners and calipers and they are all dry. so then i thought electrical. checked it all out and it is all fine yet still the brake light is on. Can some help shed some light on this problem so i can get the light out?
Posting Guru
Joined: Aug 2009
Posts: 2,271
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From: Mexia, TX
What year is your truck?
Make sure your parking brake didn't accidentally get pressed down a bit. The later 80-86 trucks were set up where the Brake light would come on if the parking brake was on, as well as if there was a brake system failure.
Make sure your parking brake didn't accidentally get pressed down a bit. The later 80-86 trucks were set up where the Brake light would come on if the parking brake was on, as well as if there was a brake system failure.
Senior User
Joined: Oct 2009
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From: Effort, PA
This. The light in my 86 stays on constantly because the parking brake doesn't return to the top all of the way.
Posting Guru
Joined: Aug 2009
Posts: 2,271
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From: Mexia, TX
See if you can find a switch on or near the parking brake assembly. If you can find one, you could try unhooking the wire if that's possible, and see if the light goes off.
Hopefully one of the more experienced brake guys around here will pop in and offer up some better knowledge on the topic.
Hopefully one of the more experienced brake guys around here will pop in and offer up some better knowledge on the topic.
Post Fiend
Joined: Jul 2004
Posts: 8,786
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From: Northern California
The cables need to be adjusted or the cable adjuster and equalizer is at the end of it's usefull life, or the cables are stretched.
Post Fiend
Joined: Jul 2004
Posts: 8,786
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From: Northern California
If the light stays on with it unplugged, make sure the ignition switch is properly adjusted and not sticking close to the start position. (Comon problem)
Most likely you have a brake problem somewhere. If there are no signs of leaks, you may have a defective master cylinder diaphram, air in one of the lines, or a problem with the porportioning valve switch or porpotioning valve itself.
The porpotioning valve switch that screws into the valve can split and leak a little brake fluid causing the switch to short out and the lamp to come on.
Hope this helps.
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OK, i had some time to check things out. the parking brake isn't causing the light to be on. i did discover that the brake pedal feels alittle soft. like it goes down farther then it use to. i did replace the powerbooster and master cylinder. this the fourth one i have put in. but the first time i see the light.i still see no leak anywhere. I check everything over two or three time to make sure. i did check the porpotioning valve switch as well and there are not leaks and it seems to be fine and i still have this darn light
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From: NoGa.
OK, i had some time to check things out. the parking brake isn't causing the light to be on. i did discover that the brake pedal feels alittle soft. like it goes down farther then it use to. i did replace the powerbooster and master cylinder. this the fourth one i have put in. but the first time i see the light.i still see no leak anywhere. I check everything over two or three time to make sure. i did check the porpotioning valve switch as well and there are not leaks and it seems to be fine and i still have this darn light
Unplug the connector at the "proportioning valve"....check the light.
If neither of these operations turn the light off ... you got a fault in the wiring ...
If either one turns the light off ... well, you found your problem.
I'm courious, however, why you are going through so many brake parts. You *may* have a bit of air in the system.
T
Tuned
Joined: Nov 2009
Posts: 264
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From: Sherman Oaks California
Try and pull up on the parking brake pedal. Also do as "Kirby" has suggested and unplug it from the switch that's on the pedal.
If the light stays on with it unplugged, make sure the ignition switch is properly adjusted and not sticking close to the start position. (Comon problem)
Most likely you have a brake problem somewhere. If there are no signs of leaks, you may have a defective master cylinder diaphram, air in one of the lines, or a problem with the porportioning valve switch or porpotioning valve itself.
The porpotioning valve switch that screws into the valve can split and leak a little brake fluid causing the switch to short out and the lamp to come on.
Hope this helps.
If the light stays on with it unplugged, make sure the ignition switch is properly adjusted and not sticking close to the start position. (Comon problem)
Most likely you have a brake problem somewhere. If there are no signs of leaks, you may have a defective master cylinder diaphram, air in one of the lines, or a problem with the porportioning valve switch or porpotioning valve itself.
The porpotioning valve switch that screws into the valve can split and leak a little brake fluid causing the switch to short out and the lamp to come on.
Hope this helps.
so many pros...
Wanted to see if you or you all can shed some light on my problem,
I have a 1986 e-150 302ci
I just lost my parking brake light, it went away intermittentlyonce or twice so I checked the bulb & its fine, when I giggled the parking brake light switch the light does'nt come on...
Is it a bad switch or maybe a short some where, right??
I don't know if this has anything to do with a surgging/hesitation problem I've had for the longest time, I pulled some codes with the engine running I think these are called "memory codes" they are codes from the past anyway one of the codes was CODE 77 Brake On/Off switch failure always ON.
I never had a problem with that light...
My rear wheel cylinders were changed & brake lines flushed on 12/20/2009 it stops better than before the fix!!!
Any thoughts
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Freshman User
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There are two switches for that brake warning light. one on the parking brake and one on the porportioning valve. make sure everything is plugged in and not loose. check your fuses. it could be a bad switch too.
Fleet Mechanic
Joined: Apr 2007
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From: patricia ab canada
if you think it's the porpotioning valve ,mash the brake peddle hard and fast a couple of times,sometimes this resets the valve.if not check all your brake lines there could be a pin hole some where in the braking system,causing a pressure difference.
Moderator
Joined: Nov 2007
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From: Denver Metro Area, CO
The electrical connections at my proportioning valve became corroded, resulting in the
light NOT working.
Unplug the connector at the proportioning valve; connect the two leads in the wiring
harness together, then connect them to a good ground - the dash light should come on
(with the key in RUN, possibly also with it in ACC).
Make sure the connectors are clean and reattach to the proportioning valve; at the
parking brake cable, unplug the wire from the switch and ground it, the light should again
come on.
I believe the wire in both cases is white/purple stripe but it could be purple/white stripe, I
don't remember.
If those tests pass, the bulb & wiring is good; if the lamp continuously stays lit,
something is grounding that wire; the proportioning valve, the parking brake switch, or a
break & short-to-ground in the wire somewhere.
I used what I call a jumper - a short piece of 18 (or so) gauge wire with alligator clips on
both ends.
light NOT working.
Unplug the connector at the proportioning valve; connect the two leads in the wiring
harness together, then connect them to a good ground - the dash light should come on
(with the key in RUN, possibly also with it in ACC).
Make sure the connectors are clean and reattach to the proportioning valve; at the
parking brake cable, unplug the wire from the switch and ground it, the light should again
come on.
I believe the wire in both cases is white/purple stripe but it could be purple/white stripe, I
don't remember.
If those tests pass, the bulb & wiring is good; if the lamp continuously stays lit,
something is grounding that wire; the proportioning valve, the parking brake switch, or a
break & short-to-ground in the wire somewhere.
I used what I call a jumper - a short piece of 18 (or so) gauge wire with alligator clips on
both ends.
Tuned
Joined: Nov 2009
Posts: 264
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From: Sherman Oaks California
[quote=86bigred;8331414]if you think it's the porpotioning valve ,mash the brake peddle hard and fast a couple of times,sometimes this resets the valve.if not check all your brake lines there could be a pin hole some where in the braking system,causing a pressure difference.[/qu
Thanks for your reply,
What you're describing would cause my brake light to be off?
Thanks for your reply,
What you're describing would cause my brake light to be off?
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
No, it would cause it to be on steady.
If it doesnt work at all... It should at least blink when you start the truck/van...
Follow what Ctubutis suggests. Someone may have unplugged the porportioning valve or the switch in the valve is faulty. Or the ignition switch is faulty, etc...
If it doesnt work at all... It should at least blink when you start the truck/van...
Follow what Ctubutis suggests. Someone may have unplugged the porportioning valve or the switch in the valve is faulty. Or the ignition switch is faulty, etc...
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