Possible Brake issue? Or.........

[retirednak]

The last week or so I've been getting a single chime when I first drive my truck. I haven't been able to see if a light comes on with the chime,my wife finally saw the brake light flash finally. Its not the ABS,but the red warning light. If the truck sits for a couple hours and gets a chance to cool completely,I'll get the chime and flash,every once in a while it may flash 2 or 3 times with the flash matching the chime. Brake fluid is fine and the emergency brake is fully released. I also noticed that I'm getting a little brake squeal when stopping. How ever that's nothing new since I have ceramic pads front and rear and they tend to make some noise with a load on the truck.

I've never changed the brake fluid,with 103000 miles,I'm sure its way over do. I did a brake job changing the original pads at 70K miles and the truck hasn't been worked hard since. To be honest with you,I haven't checked to see if the pads are worn down. (I wouldn't think they would be worn down so with so little mileage)



How bout some ideas on what to check?

Thanks-Casey

 

[rbattelle]

I find it unlikely that the pads have anything to do with this. The ABS computer doesn't have any practical way of monitoring the pad status.

The red warning light is for the emergency brake only, and it operates by a switch assembly attached to the pedal inside the cab. If it were me, I'd start looking at that switch first. Being in the cab with snowy or wet shoes may have put enough water vapor into the air under there to corrode some contacts.

Ryan

 

[retirednak]

I'll check for a funky switch or contacts. That does make sense,its rare the truck gets to park in the garage in winter and dry out. Thanks for the idea Ryan,I'll update if I find a problem.

Casey

 

[AH64ID]

The ABS system will activate the brake light.

 

[rbattelle]

The ABS system will activate the brake light.

I didn't know that! So what's the difference in faults between the ABS light and the other brake light? That would really be helpful in diagnosing Casey's problem.



In other words, what exactly determines which light the ABS computer illuminates? And, if possible, can you point me to the proper location in the FSM or PDM? I'm having trouble finding the information.



Ryan

 

[AH64ID]

I would scan it for codes to see if there are any codes. A bad wheel speed sensor can also give you the brake light.

Check the fuses, my dad had a bad trailer blow a fuse that gave him the brake light.

 

[rbattelle]

I would scan it for codes to see if there are any codes. A bad wheel speed sensor can also give you the brake light.

A bad wheel speed sensor gives the brake (not ABS light)? I didn't know that, either.

Is it reasonable to expect the system to have stored a code if the light didn't remain illuminated?

When you say, "scan it for codes" do you mean the OBD-II stream or the ABS computer?

On Edit:
Okay, I finally found the relevant portion of the FSM (8J-19 in 2003):

The brake indicator gives an indication to the vehicle operator when the parking brake is applied, when there are certain brake hydraulic system malfunctions as indicated by a low brake hydraulic fluid level condition, or when the brake fluid level switch is disconnected. The brake indicator can also give an indication when certain faults are detected in the Antilock Brake System (ABS).

That's not really all that helpful. But it does give you one more place to look: the brake fluid level switch. Try disconnecting it and cleaning the contacts.

Ryan

 

[AH64ID]

I was looking it up also, really not helpful at all. . I don't know if OBDII will tell you anything or not, but cant hurt to scan it.

 

[retirednak]

Hey Fellas,

I'll scan it tomorrow or Monday for codes. Is the brake fluid switch located on the master cylinder? I guess I need to break down and get the correct FSM. I bought what I thought was the correct manual on fleabay and it turns out it is mostly for gas engines. At least I didn't spend much money.

Thanks for all the info,

Casey

 

[rbattelle]

Yes, the brake fluid sensor is in the master cylinder reservoir, if my memory serves.

Ryan