Brake Warning Light - F150online Forums

Wheels, Tires & Brakes

Brake Warning Light


Old 05-17-2010, 02:42 PM
Junior Member
Thread Starter
Join Date: Aug 2006
Posts: 2
Brake Warning Light

Hey all! Yes, I've done a few searches on this but just wanted to see if there was any further input.

My brake warning light has been popping on/off for a while now. Sometimes it stays on after start up then goes off only to come back on, other times its off then comes on and stays on for a while then just randomly goes off. I've searched other posts and most say that it is either due to low brake fluid or a stuck e-brake pedal. I've tried pulling the e-brake up but to no avail. I've checked the fluid and it's fine. I sprayed some contact cleaner on the sensor plug at the master cylinder but it still comes and goes. Here's the wild thing...once in a while, when it comes on I will tap the area above the e-brake release or slam the door and it will sometimes (not all the time) go off.

I'm just wondering if this is the sign of a short somewhere or is there really something going on with the brakes? I haven't had a chance to pull the wheels off to see how much meat is left on the pads but they feel fine. Until I figure this out, thinking of just putting some electric tape over the light because it is annoying as hell!!

Any input would be greatly appreciated. BTW - It's a 2005 SCREW

Reply With Quote
Old 05-18-2010, 12:51 PM
Senior Member
Join Date: Dec 2004
Location: Indiana
Posts: 2,155
Try adjusting the sensor on the e-brake pedal. Perhaps the pedal is fully released but the sensor is just barely touching it.

If that doesn't work, try replacing the FLI (Fluid Level Indicator) in the reservoir. This is what they wire connects to... you should be able to squeeze the opposite side and pull it out. Get a new one from the Ford Dealer.

The FLI has a glass reed switch in it and perhaps that has gone bad or cracked.

If neither of those work, it might be an issue somewhere else in the electrical system... that could be quite difficult. So hopefully its one of these 2 easy fixes.
Reply With Quote
Old 05-18-2010, 01:01 PM
Senior Member
Join Date: Sep 2008
Location: Whittaker, MI
Posts: 348
Anyone know the part number for the fluid level indicator?

I asked this in another thread and just got a bunch of suggestions from people to check my e-brake sensor. Well, I know it's not that, as I've checked EVERYTHING in the brake system, and even had one of my co-workers check it too. I tend to trust his opinion on stuff, as he's an ASE Master Technician with 33 years in the industry.
Reply With Quote
Old 05-20-2010, 03:08 PM
Junior Member
Thread Starter
Join Date: Aug 2006
Posts: 2
Thanks for the input. I'm suspecting the FLI as well. Yesterday, when I pulled in my garage the light was still on so I decided to leave the engine running and pull the FLI. Light did go off then when I plugged it back in light came back on. I figured that may have been it but when I unplugged it, this time the light stayed on. Unplugged it...light stayed on. WTF?!?! I'll try toying around with the e-brake sensor some more and see what's up.
Reply With Quote
Old 05-21-2010, 12:57 PM
Senior Member
Join Date: Dec 2004
Location: Indiana
Posts: 2,155
Most FLIs are diagnostic... they either have 3 pins or have 2 pins and a small resistor so the computer knows if they are unplugged and keeps the light on.

Otherwise if your FLI wire broke you would never know if your brake fluid was low.

As for the on/off/on... it might take the computer a little while to notice that its unhooked...
Reply With Quote

Related Topics
Thread Starter
Last Post
Chips, Tuners & Programming
09-26-2015 12:41 PM
Electrical Systems
07-20-2015 10:45 PM
2004 - 2008 F-150
07-16-2015 03:40 PM
Electrical Systems
07-13-2015 12:19 PM

Thread Tools
Search this Thread
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


All times are GMT -4. The time now is 11:12 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: