Emergency brake light
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Junior Member
Joined: Dec 2017
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Emergency brake light
I have a 1986 f150. My emergency brake warning light turned on while I was driving. I checked my master cylinder and brake fluid was low in the rear. I filled it up and light still on. I changed rear brakes (springs, pads, brake cylinder) and bleed it. Light still on. I even tried to center pressure differential valve on master cylinder. Light still on. So my question is does anyone know what else I could try? I know it’s really not a big deal. My truck brakes work and it’s an old truck. But I’m a little OCD and it wasn’t on previously. Thank you in advance for those who will reply.
Member
Joined: Jan 2018
Posts: 11,256
Likes: 1,770
From: Memphis, TN, Earth, Milky Way
Your truck's brake light is triggered by the e-brake pedal & the differential valve; not fluid level. If the e-brake pedal is fully-released, either the wire is shorted to ground, or the valve needs to be re-centered (very likely, considering the leak). The procedure is too long & complicated to post, but it's published in Haynes:
(phone app link)
(phone app link)
