MY '97 Ram 1500 4x4 5.2L engine has an issue regarding ABS/Brake light. My wife had complained of ABS/brake light coming on the week before a rear brake line let go. I replaced the rotted line, new brake fluid and bled lines to the rear. ABS light and brake light on dash - still on. I then decided to replace the speed sensor on rear differential, still the lights will not clear. Any suggestions where to go from here would be greatly appreciated!!!

 

Hope you get your answer, because I've been fighting this issue for over 2 years.

 

Try unplugging the pressure differential switch on the combination valve. If the light goes out (and you know you've got good pressure in both brake circuits, and the wiring isn't compromised) the switch is stuck.

I'm not certain if it's true about these trucks, but on many other vehicles the switch can sometimes be freed by lightly tapping on the plunger or the combination valve near it with a small hammer. If that doesn't work, well, it's a "serviced as a unit" part. Bummer.

 

Thanks for the advice. I'll try those two ideas. Tomorrow is another day!!!

 

Another thing you can try, if the above suggestions don't help....... Grab a friend (or your wife...) sit them in the drivers seat. Have them pump up the brakes, and hold FIRM pressure on the pedal. Then, you crack open one of the rear bleeders. When the pedal hits the floor, close the bleeder. Step on the brakes a couple times. Is the lite out? If it is, yer done, if it isn't, do the same thing, but, crack open one of the FRONT bleeders.

This process works for me damn near every time.

 

I'll try that this weekend. If that doesn't work my next step is to replace the proportioning valve.....in the warmer weather.