brake light in the dash

[85 Jimmy]

has anyone had this problem?
when i push the brake sometimes i can feel a pop and the brake light in the dash will come on, then i'll push the brake again and i'll feel the pop and it'll go away?

my truck is an 85 gmc jimmy

 

[Chrisblazzer89]

I have the same problem in my 88 blazer hope someone can come up with an answer.

 

[skyyk5]

yep. And I found out what it was pulling a 19' deep-v (heavy ) boat. I had a bad wheel cylinder. It was leaking, then not leaking. I replaced it and I was good , for a while. Then it happened to me again. Two peddal pushes away from the line that blew out. Check for rotted lines/leaks. Sometimes the rust can act like a check valve so it's not always leaking. The light is for "loss/ not enough pressure"

 

[85 Jimmy]

i thought it could be a wheel cylinder so i checked and neither one is leaking, also my fluid level is full

i've replace the front hoses, along with every other brake component in the front.

i guess i'll put it on a rack at work and check out the rears again though...

 

[skyyk5]

check your lines along the frame. mine was bad at the bend before it turns to rubber, for the rear axel. I beleave it was aways the problem, and the wheel cylinder just made it worse. Have the truck dry, before putting on the lift and pump the brakes hard and fast. Then you just "look for the wet spot".

 

[goldwing2000]

If you can't find any external leaks, it could be an internal leak in the master cylinder. The light senses when the pressure differential is too great between the front and rear systems, so a leak between the two chambers of the master can cause that.

It could also be as simple as the rear brakes not being adjusted properly. When the drums aren't adjusted right, it thows off the pressure balance.

The pop could be the brake shoes popping in and out of a groove in the backing plate. Inspect your backing plates for excessive wear. Make sure your brake shoes move freely and are adjusted out to where they just barely contact the drum.