Brake warning light
Thread Starter
|
New User
Joined: Sep 2007
Posts: 17
Likes: 0
Brake warning light
Hello, I hope that you can help me. I am over in the UK, and I have a 1994 USAF Spec F350 diesel truck.
Recently I have started to get the brake warning light and ABS light come on together whilst driving along (I dont have ABS, only a warning light !)
I have checked everything in the front and rear brakes, and everything seems OK, the brakes also work fine. I am guessing that it could be a fault in the dash as it is intermittent, and also the battery light comes on now and then even though there is no charging problem. The brake fluid resevoir is full.
Is there anything obvious I am missing ?
Your help would be greatly appreciated
Recently I have started to get the brake warning light and ABS light come on together whilst driving along (I dont have ABS, only a warning light !)
I have checked everything in the front and rear brakes, and everything seems OK, the brakes also work fine. I am guessing that it could be a fault in the dash as it is intermittent, and also the battery light comes on now and then even though there is no charging problem. The brake fluid resevoir is full.
Is there anything obvious I am missing ?
Your help would be greatly appreciated
Elder User
Joined: May 2004
Posts: 790
Likes: 0
From: Danville, Pa
Your truck comes standard with rear ABS. Does your cruise control work? Speedo smooth and accurate? Have you noticed any difference on required brake pedal force to stop? Or different travel length?
Thread Starter
|
New User
Joined: Sep 2007
Posts: 17
Likes: 0
My truck has all the usual military spec extras (ie. none !)
It hasnt got cruise control. The speedo seems to be just fine. The brake pedal does feel a tiny little bit different, a bit like the braking is more in the rear than normal. No difference in travel length. I might be wrong, but I cant see any signs of ABS, no sensors, etc...
It hasnt got cruise control. The speedo seems to be just fine. The brake pedal does feel a tiny little bit different, a bit like the braking is more in the rear than normal. No difference in travel length. I might be wrong, but I cant see any signs of ABS, no sensors, etc...
Post Fiend
Joined: Jan 2005
Posts: 8,402
Likes: 10
Your truck should have RABS as LilDuke says. You should see the sensor for it on the rear differential housing. I`m pretty sure that by `94 that sensor is also used for the speedo. Your problem with the dash lights on is most likely caused by loose/dirty wiring connections at the master cylinder. Check also that your stop lights are working as failure there can cause the RABS light.
Elder User
Joined: Aug 2007
Posts: 728
Likes: 0
your chasing the wrong sensor ,the vss sensor has nothing to do with the red brake light
since both are on the only shared component is the brake fluid level sensor
it has three wires to it and the sensor jumps two of those wires together to complete a circuit to the rabs module
the sensors contacts are known for corrosion
remove the plug and clean the connections on the sensor itself
since both are on the only shared component is the brake fluid level sensor
it has three wires to it and the sensor jumps two of those wires together to complete a circuit to the rabs module
the sensors contacts are known for corrosion
remove the plug and clean the connections on the sensor itself
Trending Topics
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
The brake light will also come on when you have low vacuum to assist with brake application.
Your vacuum pump may be on the way out.
Your vacuum pump may be on the way out.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Elder User
Joined: May 2004
Posts: 790
Likes: 0
From: Danville, Pa
I thnk both Dave and Kevin have it. As I am going through this myself. The pulley on my remanned alt is larger(turns slower) and that makes my pump barely adequate under 1000rpm. Of course I just re-read your's is a 94. Other than no more mech speedo, I don't know what other changes the IDI's got.
Thread Starter
|
New User
Joined: Sep 2007
Posts: 17
Likes: 0
Hello again everyone.
Well thanks to your help, the problem is solved. All I did was take off all of the wires on the brake master cylinder and the sensor on the rear diff. Clean them all and put them back and the problem has not happened since. Brilliant !
On another subject. The reason I thought that there wasnt any ABS is that the rear end locks up all the time when I am runnning empty. Is this normal
Again thanks for your help
Well thanks to your help, the problem is solved. All I did was take off all of the wires on the brake master cylinder and the sensor on the rear diff. Clean them all and put them back and the problem has not happened since. Brilliant !
On another subject. The reason I thought that there wasnt any ABS is that the rear end locks up all the time when I am runnning empty. Is this normal
Again thanks for your help
Post Fiend
Joined: Jan 2005
Posts: 8,402
Likes: 10
Rear end locking up is not normal. I would first pull the rear drums. Make sure your shoes are good but look for any leak of brake fluid or gear oil. If everything is OK replace drums and adjust shoes. If your rear brakes are OK and the RABS is working you should feel a pulsating thru the brake pedal if the rear brakes start to luck up. Also some types of brake lining are more likely to lockup in wet weather but will usually return to normal after a few applications of the brakes. Finally, if all is well with the rear brakes but they still lock I would point the finger at the proportioning valve. Unfortunately this is incorperated in the RABS valve block (on inside of left side frame rail about level with driver`s feet) so expensive to replace. Are you in the UK? If so then your RABS may have been disabled when the lights were rewired. However that would not affect the proportioning valve.
Elder User
Joined: Aug 2007
Posts: 728
Likes: 0
the rabs would not have operated with the electrical issues
now that you have corrected that test the rear antilocks on wet pavement
also you can have one wheel lock up on any rabs equipeed vehicle due to one wheel having an aggressive set of brake shoes
the rabs will not activate as long as one wheel is turning and allowing the diff carrier to roate
now that you have corrected that test the rear antilocks on wet pavement
also you can have one wheel lock up on any rabs equipeed vehicle due to one wheel having an aggressive set of brake shoes
the rabs will not activate as long as one wheel is turning and allowing the diff carrier to roate
Elder User
Joined: May 2004
Posts: 790
Likes: 0
From: Danville, Pa
My pump is driven off my alt.