Brake warning light problem

[jholaway1971]

To start off my brake pedal feels really good but brake warning light in the dash stays on so I was told to change the ABS sensor on the rear end so I did that and still the light stays on. So I change the back brakes shoes they were worn but not beyond the point where it causes drum damage. I adjusted them and the front brakes and rotors have already been changed before I got the truck by Midas in January 2014 (found the receipt in glove box) so I was told to bleed the brakes at each wheel so I did and bled the master cylinder too. I even checked the parking brake switch (basic two copper pieces making contact) and that looks fine.
I also checked the switch (black plug) at the combination valve as seen in this photo:
https://lh3.googleusercontent.com/-.../geI1ZhDIwGQ/w737-h553-no/20140314_113526.jpg

I also would like to know what is this that has brake lines going to it from the combination valve with the white plug:
https://lh6.googleusercontent.com/-.../Wchbs2GpK30/w737-h553-no/20140314_113539.jpg

My oldman says I should buy a new master cylinder even though I have great brakes.

 

[leadrofthepak]

I am not convinced it is the master cylinder. You have good brakes which means you have good hydraulic pressure as long as your pedal travel is not excessive. I would investigate sensors, relays, fuses, electrical wires/connections, etc. to try and resolve the dash light issue. Seems to me to be electronic, not hydraulic.

 

[jholaway1971]

That is what I think but auto parts store that checks the electrical system "Check Engine" light reset says they can't diagnose any brake/ ABS related problems with their scanner. So I am at a loss where to check next

 

[leadrofthepak]

Yeah the scanners that can diagnose abs are significantly more expensive

 

[jholaway1971]

I may have to bite the bullet and take it to a brake place like Midas and have them diagnose the problem

 

[Markbone]

does your parking brake pedal stick like mine does? everytime i release it i have to pull up on it and it moves another 1-2". i think my spring is just old and worn out, maybe give that a check?

 

[jholaway1971]

No my parking brake releases just fine just the pedal doesn't stay down when I do engage it but it seems it was made to do that in these trucks for some reason.

 

[jholaway1971]

Well I pulled the dash out and there are 4 small bulbs missing at the bottom where all the warning lights are and behold one of those missing lights is the ABS light. The local auto parts store will have them in tomorrow morning so I will get the dash back together then with the new bulbs.




I guess I have bigger problems due to the ABS light is missing

 

[jholaway1971]

Well I got the bulbs installed and dash back together and the f#$%ing ABS and Brake warning light is lit up. I know this changes the dynamics in troubleshooting the problem.
Any suggestions I can try before I take it down to the brake shop and pay their hefty troubleshooting costs ?

 

[jholaway1971]

Well I just back from my local mechanics repair shop and they hooked the ABS scanner up to my truck and found no error codes or any other problems with my braking system. He was at a loss why the light was on and he tried to reset the ABS and brake light and it wouldn't reset. I asked about front ABS sensors and he informed me that there are no front ABS sensors on my truck just a rear ABS system. I also asked about the main ABS module if there could be a problem with it and he was like well there is a possibility but I wouldn't waste money changing that because they are fairly expensive. He did offer to keep the truck for a few days and go through the whole electrical system to see why the light was on but there was no guarantee that he could find the problem. His honest opinion was to ignore the lights and just drive the truck. I now know why the bulbs were missing in the dash.

Now with that info does anyone have any suggestions of what I could check or should I just say hell with the lights in the dash and just drive the truck ?

 

[John Walters]

I had an issue where the brake indicator was flashing and driving me nuts. I checked the fluid, fine. I checked the emergency brake, disengaged. Pulled the brake release lever, done. Then I decided to hold the brake release lever and manually raise up on the emergency brake. Found out there was an additional inch of play that when I pulled up on the brake itself, stopped the darn light from being on and blinking. Sometimes the simplest fix is the right one.