Notices
2004 - 2008 F150 2004, 2005, 2006, 2007 and 2008 Ford F150's with 5.4 V8, 4.6 V8 engine
Sponsored by:
Sponsored by:

How to Replace Brake Fluid Level Sensor

Thread Tools
 
Search this Thread
 
Old Jun 10, 2014 | 10:33 AM
  #1  
schief's Avatar
schief
Thread Starter
|
New User
Joined: Jun 2014
Posts: 3
Likes: 0
From: Central-PA
How to Replace Brake Fluid Level Sensor

Hi All, new member here looking for some instruction. Just bought a 2007 supercab with the 5.4 in nice shape, but have an intermittent brake light on the dash. (No ABS, just the brake light.) Our mech. diagnosed a bad Brake Fluid Level switch, and wants over $200 to replace ($150 just for the new switch). I can get a new sensor for $30 at NAPA. I don't understand how there can be such a huge difference, but in any event, I'd like to try and replace this myself and save a lot of money if it's not too difficult.

I'm looking for some clear step-by-step directions on doing this, and have a couple of questions:

Do I need to disconnect the battery first?

Do I need to empty the brake fluid reservoir? (Looks like the sensor is in the bottom of the reservoir, if I take it out without draining res, will I have a mess?)

When looking up the sensor online, I also saw the plug/connector for sale, should I replace that as well?

Thanks in advance.
 
Reply
Old Jun 20, 2014 | 05:31 AM
  #2  
60DRB's Avatar
60DRB
Laughing Gas
15 Year Member
Liked
Loved
Joined: Dec 2009
Posts: 799
Likes: 13
From: East L.A.
I haven't looked at this on my truck, but my mother in law's Aerostar had the brake light on all the time... I replaced the sensor in the bottom of the brake fluid reservoir and the problem was solved. The dealer wanted to replace the ABS unit and the sensor, for $500+. If not damaged/corroded the plug is fine. I'm lazy and don't generally disconnect the battery when working on my truck. I've noticed the dealer is the same way!

"Our mech. diagnosed a bad Brake Fluid Level switch, and wants over $200 to replace ($150 just for the new switch). I can get a new sensor for $30 at NAPA. I don't understand how there can be such a huge difference, " ...because they have overhead costs, insurance, have to make a living, etc.

I just put a rag under the reservoir when I removed the sensor- I actually let a little fluid run/drip out to clear any sediments from the thread area. Before actually removing the sensor I loosened it, and prepped the new one, ecpecting a flood of fluid (no flood, just moderate dripping- I left the fill cover on). I put one wrap of teflon tape on the new part and all has been well for over a year. Just don't over torque the part, as the reservoir is plastic. Duh.

How to Remove Brake Fluid Level Switch - F150online Forums

https://www.ford-trucks.com/forums/8...el-sensor.html
 
Reply
Old Jun 20, 2014 | 06:36 AM
  #3  
schief's Avatar
schief
Thread Starter
|
New User
Joined: Jun 2014
Posts: 3
Likes: 0
From: Central-PA
Originally Posted by 60DRB
I haven't looked at this on my truck, but my mother in law's Aerostar had the brake light on all the time... I replaced the sensor in the bottom of the brake fluid reservoir and the problem was solved. The dealer wanted to replace the ABS unit and the sensor, for $500+. If not damaged/corroded the plug is fine. I'm lazy and don't generally disconnect the battery when working on my truck. I've noticed the dealer is the same way!

"Our mech. diagnosed a bad Brake Fluid Level switch, and wants over $200 to replace ($150 just for the new switch). I can get a new sensor for $30 at NAPA. I don't understand how there can be such a huge difference, " ...because they have overhead costs, insurance, have to make a living, etc.

I just put a rag under the reservoir when I removed the sensor- I actually let a little fluid run/drip out to clear any sediments from the thread area. Before actually removing the sensor I loosened it, and prepped the new one, ecpecting a flood of fluid (no flood, just moderate dripping- I left the fill cover on). I put one wrap of teflon tape on the new part and all has been well for over a year. Just don't over torque the part, as the reservoir is plastic. Duh.

How to Remove Brake Fluid Level Switch - F150online Forums

https://www.ford-trucks.com/forums/8...el-sensor.html
Did you drain the fluid out of the reservoir before taking the sensor out? (as much as possible?)

Did you disconnect the battery first?
 
Reply
Old Jun 21, 2014 | 06:02 AM
  #4  
60DRB's Avatar
60DRB
Laughing Gas
15 Year Member
Liked
Loved
Joined: Dec 2009
Posts: 799
Likes: 13
From: East L.A.
I did not drain any fluid except like I described, to clear any sediment from the thread area. I had a bottle of fluid on hand to top off if needed. I didn't disconnect the battery when I did it, but shop manuals say to disconnect the battery for everything except changing tires.
 
Reply
Old Jun 21, 2014 | 09:46 AM
  #5  
ojai150's Avatar
ojai150
More Turbo
15 Year Member
Joined: Jan 2008
Posts: 538
Likes: 24
From: Ojai California
Originally Posted by 60DRB
I did not drain any fluid except like I described, to clear any sediment from the thread area. I had a bottle of fluid on hand to top off if needed. I didn't disconnect the battery when I did it, but shop manuals say to disconnect the battery for everything except changing tires.
Thank you for sharing this successful project , but I'm curious as to why you would attempt to change your tires without unhooking your battery , (this doesn't sound very safe).
 
Reply
Old Jun 21, 2014 | 08:20 PM
  #6  
danorules's Avatar
danorules
Postmaster
Joined: Jan 2010
Posts: 4,329
Likes: 4
From: manchester,ct
Originally Posted by ojai150

Thank you for sharing this successful project , but I'm curious as to why you would attempt to change your tires without unhooking your battery , (this doesn't sound very safe).
Hahaha .
 
Reply
Old Jun 22, 2014 | 05:58 AM
  #7  
60DRB's Avatar
60DRB
Laughing Gas
15 Year Member
Liked
Loved
Joined: Dec 2009
Posts: 799
Likes: 13
From: East L.A.
I'm just lazy like that. ...and now the thread wanders off into left field. All because I left the battery connected.
 
Reply
Old Jun 23, 2014 | 06:53 AM
  #8  
schief's Avatar
schief
Thread Starter
|
New User
Joined: Jun 2014
Posts: 3
Likes: 0
From: Central-PA
I'm surprised they don't have you disconnect the battery before changing tires, since many vehicles have sensors on tires now.

Seriously though, thanks for the advice.

By the way, what did you mean by "prep the New sensor"?
What is there to prep other than wrapping some teflon tape around threads maybe?
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-1

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-2

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-3

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-4

Every 2026 Ford Engine Explained

 Brett Foote
story-5

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-6

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-7

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-8

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-9

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
Old Jun 23, 2014 | 07:30 AM
  #9  
ojai150's Avatar
ojai150
More Turbo
15 Year Member
Joined: Jan 2008
Posts: 538
Likes: 24
From: Ojai California
Originally Posted by schief
I'm surprised they don't have you disconnect the battery before changing tires, since many vehicles have sensors on tires now.

Seriously though, thanks for the advice.

By the way, what did you mean by "prep the New sensor"?
What is there to prep other than wrapping some teflon tape around threads maybe?
He meant , don't simply tape it up and screw it in ,......take the time to sit and have a meaningful discussion with the sensor , and prepare it for a fruitful life , become "one with the sensor ",......
 
Reply
Old Jun 26, 2014 | 06:11 AM
  #10  
60DRB's Avatar
60DRB
Laughing Gas
15 Year Member
Liked
Loved
Joined: Dec 2009
Posts: 799
Likes: 13
From: East L.A.
Originally Posted by ojai150
He meant , don't simply tape it up and screw it in ,......take the time to sit and have a meaningful discussion with the sensor , and prepare it for a fruitful life , become "one with the sensor ",......

Yep. It has to be in the right mood before instalation.... out of the wrapper, taped, within reach, and ready to install.
 
Reply
Old Jun 26, 2014 | 11:33 PM
  #11  
Crazy4x4's Avatar
Crazy4x4
New User
Joined: Jun 2013
Posts: 24
Likes: 0
For the brake light only!
1. The Ebrake switch is bad or stuck or bad wiring
2. The low brake fluid switch is bad or just low fluid or bad wiring
3. The ABS is not communicating with the instrument panel (check plugs and wires, test the continuity of the wires)
4. The instrument panel is at fault, there was a known problem of internal shorts. Go here for a repair shop. Brian's Speedometer Repairs - FORD CLUSTER REPAIRS - Muldrow, OK
I have the brake light on too, which after diagnosing it is the cluster that is at fault, I need to send it in one day.

Unfortunately, there is no bulb that can be removed, I believe it is an integrated LED. It only takes 5 mins to remove the instrument cluster.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jgilrfr
1999 - 2003 7.3L Power Stroke Diesel
2
Dec 29, 2011 01:02 AM
jgilrfr
1999 - 2003 7.3L Power Stroke Diesel
1
Dec 28, 2011 06:54 PM
camodown
1999 - 2003 7.3L Power Stroke Diesel
7
Jan 25, 2009 11:11 AM
yesitsmelarry
1973 - 1979 F-100 & Larger F-Series Trucks
3
Mar 7, 2005 08:34 PM
hostile413
1987 - 1996 F150 & Larger F-Series Trucks
2
Mar 7, 2004 01:11 PM




All times are GMT -5. The time now is 06:13 AM.

story-0
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-1
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-2
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-3
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-4
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE