Brake warning light question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sb69chevy · 04-12-2007, 03:46 PM

Okay. Had my brakes worked on, and after they were fixed my warning light has stayed on constantly. Looked at the valve and followed the wire...looks like the wire has been pinned between the firewall and m/c. Would this cause the misreading? (Warning light worked fine before this.) If not, any other ideas?

bobthecop · 04-12-2007, 03:58 PM

Sounds like the problem, fix that and see if it works ok.

sb69chevy · 04-12-2007, 04:00 PM

Thanks bob. Will do.

Longhorn Man · 04-12-2007, 05:25 PM

if it is grounded to the firewall, then the light will come on.

mnunn454 · 04-12-2007, 05:50 PM

Yup.

That and the parking brake are both the type of circuits that illuminate when they're grounded.

They make for lots of "ammusement" when you're rewiring your gauge cluster and trying to keep the b+ switched, and ground switched circuits separate but still powered with b+, but I digress......

sb69chevy · 04-13-2007, 03:34 PM

This was the problem...Had to doctor the wire a tad from being smashed, but warning light is no longer on. Thanks.

Orange · 04-13-2007, 03:46 PM

I know you got your problem fixed, but perhaps someone will see my question on this similar problem.

My light is steady on, and goes off when you unplug it from the Prop. Valve. Bad valve like I am suspecting most likely?

DLB

sb69chevy · 04-13-2007, 04:09 PM

Not sure...here's a TTT for ya.

Longhorn Man · 04-13-2007, 04:43 PM

Orange... either that, or the valve is doin it's job.
First, check the fluid in the master cylinder.
If the level is good, then start off with inspecting the brake lines, and the insides of the drums. You are looking for kinks in the lines, or cylinders that are leaking. Take a peek at the calipers too, again, wet is bad. Now, even if all seems good, bleed the brakes. Think of this as a good idea to flush out all the old fluid anyways. I say bleed untill fresh fluid comes out. This will remove all the water, rust, and other bad things in the fluid...including any air that may be trapped, causing the light to come on.
If the light is still on, then try recentering the proportioning valve. With the truck stopped, stomp on the brake pedal like you're doin 150 MPH and a cow just jumped in front of you. This should recenter the piston in there.
If, after all this, the light is still on, and it in fact turns off when you unplug the brown wire on the valve.. then it is time to look for a new valve, and if I'm not mistaken, they are not avalible new. (please double check that one though... not just my word)

04-12-2007, 03:46 PM	#1
sb69chevy Registered User Join Date: Oct 2006 Location: Springfield, MO Posts: 375	Brake warning light question Okay. Had my brakes worked on, and after they were fixed my warning light has stayed on constantly. Looked at the valve and followed the wire...looks like the wire has been pinned between the firewall and m/c. Would this cause the misreading? (Warning light worked fine before this.) If not, any other ideas? __________________ 1969 C/10 swb, 350, powerglide (daily driver) 2005 CRV (wife's ride)

04-12-2007, 03:58 PM	#2
bobthecop Senior Member Join Date: Nov 2006 Location: Yukon Oklahoma Posts: 2,647	Re: Brake warning light question Sounds like the problem, fix that and see if it works ok. __________________ Happiness is towing your "new" truck home. 1972 C-10 1982 GMC (parts truck??) 1969 c10 parts truck 1969 C-10 ( my sons) 1992 Silverado 4X4 (now the boys truck)(now mine again) 2002 Tarus (my wife loves that car)

04-12-2007, 04:00 PM	#3
sb69chevy Registered User Join Date: Oct 2006 Location: Springfield, MO Posts: 375	Re: Brake warning light question Thanks bob. Will do. __________________ 1969 C/10 swb, 350, powerglide (daily driver) 2005 CRV (wife's ride)

04-12-2007, 05:25 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Brake warning light question if it is grounded to the firewall, then the light will come on.

04-12-2007, 05:50 PM	#5
mnunn454 Registered User Join Date: Dec 2006 Location: Rhode Island Posts: 602	Re: Brake warning light question Yup. That and the parking brake are both the type of circuits that illuminate when they're grounded. They make for lots of "ammusement" when you're rewiring your gauge cluster and trying to keep the b+ switched, and ground switched circuits separate but still powered with b+, but I digress...... __________________ 69 C-10 SWB Fleetside 454/TH400 (For Sale) http://67-72chevytrucks.com/vboard/c...ct=1299&cat=12 70 El Camino 454 TH700 29 Model A 4-DR Sedan Deluxe

04-13-2007, 03:34 PM	#6
sb69chevy Registered User Join Date: Oct 2006 Location: Springfield, MO Posts: 375	Re: Brake warning light question This was the problem...Had to doctor the wire a tad from being smashed, but warning light is no longer on. Thanks. __________________ 1969 C/10 swb, 350, powerglide (daily driver) 2005 CRV (wife's ride)

04-13-2007, 03:46 PM	#7
Orange Licensed to Thrill! Join Date: Apr 2006 Location: Northwest, GA Posts: 1,673	Re: Brake warning light question I know you got your problem fixed, but perhaps someone will see my question on this similar problem. My light is steady on, and goes off when you unplug it from the Prop. Valve. Bad valve like I am suspecting most likely? DLB __________________ 1971 GMC.Lowered. Overdrive. Orange. Krue's excellent FAQ Index.

04-13-2007, 04:09 PM	#8
sb69chevy Registered User Join Date: Oct 2006 Location: Springfield, MO Posts: 375	Re: Brake warning light question Not sure...here's a TTT for ya. __________________ 1969 C/10 swb, 350, powerglide (daily driver) 2005 CRV (wife's ride)

04-13-2007, 04:43 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Brake warning light question Orange... either that, or the valve is doin it's job. First, check the fluid in the master cylinder. If the level is good, then start off with inspecting the brake lines, and the insides of the drums. You are looking for kinks in the lines, or cylinders that are leaking. Take a peek at the calipers too, again, wet is bad. Now, even if all seems good, bleed the brakes. Think of this as a good idea to flush out all the old fluid anyways. I say bleed untill fresh fluid comes out. This will remove all the water, rust, and other bad things in the fluid...including any air that may be trapped, causing the light to come on. If the light is still on, then try recentering the proportioning valve. With the truck stopped, stomp on the brake pedal like you're doin 150 MPH and a cow just jumped in front of you. This should recenter the piston in there. If, after all this, the light is still on, and it in fact turns off when you unplug the brown wire on the valve.. then it is time to look for a new valve, and if I'm not mistaken, they are not avalible new. (please double check that one though... not just my word)



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