brake light came on

[Jay Bird]

Had brakes pads installed on front of my 89 Blazer a couple of months ago. Drove today and the brake light came on. If I put truck in park and set and release the e-brake, the light goes out but comes back on as soon as I apply brake and put in gear.

 

[4X4HIGH]

You probably have air in the system somewhere. Look for any obvious leaks everywhere. First check the fluid level in the master though.

 

[Jay Bird]

Thanks, I'll check it out.

 

[Blue90]

is it on steady or blinking?

 

[dremu]

is it on steady or blinking?

Should only blink on 90-91, which have that evil RWABS.

Oh, and to the OP, the combo valve is what actually sets the light, so if you have a major difference in pressure from front to rear, the light comes on. This can be due to low fluid, but if it got that low, the system prolly needs to be bled of air, as mentioned.

It can also happen during brake servicing, and all that need be done is pushing the rubber nipple (heh heh, he said "rubber nipple") on the combo valve. On your truck, it's on the back side of the crossmember; there's a metal box about 1" x 4" with a bunch of plumbing going into it, and on the ... hmm, IIRC driver's side, you should have a rubber nipple about 3/8" or so diameter, maybe 1/4" thick. Push it in -- you can do it hard, but just with your thumb, don't use a hammer or anything.

Doesn't hurt to reset the thing; worst case if something is wrong it'll pop back out again and you go through the above steps.

HTH.

-- A

 

[Jay Bird]

Checked the fluid last night and it is full. Will look for metal box this morning.

Thanks

 

[readymix]

Easy to find.
Look on the back side of the crossmember under the radiator.

 

[Jay Bird]

Worst case? If it pops back out what steps do you mean go through again, pushing nipple in again?

 

[BGKYK5]

My '89 tends to set the brake light after going over bumps (especially RR tracks). MC is full.

***get your sig editors ready***

Maybe I need to play with my nipple too.

 

[dremu]

Worst case? If it pops back out what steps do you mean go through again, pushing nipple in again?

Nah, if the light comes back on after resetting the valve, you have Serious Brake Problems, i.e. you need to bleed the system, check for leaks, etc etc.

-- A

 

[Jay Bird]

What is the valve for or what does it do?

Thanks

 

[4X4HIGH]

What is the valve for or what does it do?

Thanks

The valve is called a proportioning valve and it's job is to divide up (proportion) the brake pressure to the front and rear brakes.