Why are my brake lights on? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jimmydean · 10-14-2006, 11:26 PM

I got a power booster and master cyl with proportioning off a 'Burb. I just installed them along with my drop spindle disc kit. I have not bled the brakes yet, but I noticed when I connected the brake light switch, my lights came on.

Is it because there is little or no preasure in the system? I haven't looked at the fluid level, I was going to do that in the morning when I bleed the brakes. I plan on flushing the whole system with all new fluid.

I swapped the switch with the one that was in my old master cyl, to no avail. Any ideas?

Longhorn Man · 10-14-2006, 11:32 PM

With the power brakes, the pedal is much lower... as far as your switch knows, you have the pedal pressed 1/2 way down. you need to adjust the switch in towards the pedal.

jimmydean · 10-14-2006, 11:38 PM

The pedal seems to be where it used to be, but I'll look in the morning. It was dark when I was bolting stuff up for the night.

Is there a switch near the pedal? I thought there was only a switch in the proportioning valve.

Thanks for the info.

Longhorn Man · 10-14-2006, 11:56 PM

The switch in the prop valve is for the brake warning light in the dash...for the dummy light.

Werewolf · 10-15-2006, 03:16 AM

There should be a switch under the dash on or near the brake pedal itself. It could be stuck, or could just be out of adjustment. The switches were set to kick on with just a bit of brake pedal pressure, so if your pedal moved even a little, it could be enough to throw the adjustment off.

rodstored-72 · 10-15-2006, 11:21 AM

i agree with werewolf. i had just the same problem, but opposite- my brake lights would not come on. i had a guy that knows what he's doing look at it & in about a half hour he adjusted my brake light switch to where everything works. i ofcourse didn't know that the "switch" was adjustable until i went out & bought a 300 dollar dash harness & still had no luck! i wish i had known that the little "thingy" above the column was a "switch" & that it was adjustable!! i learned that there is a reason these guys get $60-75 an hour.

anyways from my "experience" i would say that you need to adjust the brake light switch...

good luck!!
rodstored-72

10-14-2006, 11:26 PM	#1
jimmydean Registered User Join Date: May 2005 Location: Beaverton, OR Posts: 3,728	Why are my brake lights on? I got a power booster and master cyl with proportioning off a 'Burb. I just installed them along with my drop spindle disc kit. I have not bled the brakes yet, but I noticed when I connected the brake light switch, my lights came on. Is it because there is little or no preasure in the system? I haven't looked at the fluid level, I was going to do that in the morning when I bleed the brakes. I plan on flushing the whole system with all new fluid. I swapped the switch with the one that was in my old master cyl, to no avail. Any ideas?

10-14-2006, 11:32 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Why are my brake lights on? With the power brakes, the pedal is much lower... as far as your switch knows, you have the pedal pressed 1/2 way down. you need to adjust the switch in towards the pedal.

10-14-2006, 11:38 PM	#3
jimmydean Registered User Join Date: May 2005 Location: Beaverton, OR Posts: 3,728	Re: Why are my brake lights on? The pedal seems to be where it used to be, but I'll look in the morning. It was dark when I was bolting stuff up for the night. Is there a switch near the pedal? I thought there was only a switch in the proportioning valve. Thanks for the info.

10-14-2006, 11:56 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Why are my brake lights on? The switch in the prop valve is for the brake warning light in the dash...for the dummy light.

10-15-2006, 03:16 AM	#5
Werewolf Woof? Join Date: Jun 2005 Location: Raleigh, NC Posts: 276	Re: Why are my brake lights on? There should be a switch under the dash on or near the brake pedal itself. It could be stuck, or could just be out of adjustment. The switches were set to kick on with just a bit of brake pedal pressure, so if your pedal moved even a little, it could be enough to throw the adjustment off. __________________ 1968 LWB CST BB 2004 Avalanche Z71 LT3. 2003 S-10 ZR2 (hers). 1997 Astro 1992 Caprice wagon, 500k stock miles. Nursing wounds after a bad wreck. 1997 Saturn - need gas mileage from something!

10-15-2006, 11:21 AM	#6
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,985	Re: Why are my brake lights on? i agree with werewolf. i had just the same problem, but opposite- my brake lights would not come on. i had a guy that knows what he's doing look at it & in about a half hour he adjusted my brake light switch to where everything works. i ofcourse didn't know that the "switch" was adjustable until i went out & bought a 300 dollar dash harness & still had no luck! i wish i had known that the little "thingy" above the column was a "switch" & that it was adjustable!! i learned that there is a reason these guys get $60-75 an hour. anyways from my "experience" i would say that you need to adjust the brake light switch... good luck!! rodstored-72



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