GM-GMC: 1997 chevy k1500 tail lights, chevy k1500, bleeders

Question
I have a 97 k1500 w/ ABS it has 100k miles. My prob. is when I hit the brakes, the rear
brake light initially goes on, but then the pedal goes down farther the B-lights go off. I
put in a new relay,pedal switch, that didn't help. Assuming if the pedal was not going
down so far, the lights would stay on? I put in new front brake pads,didn't help / new
master cylinder / still have the prob;em?
How do you suggest I get the rear brake light to stay on?
Thanks for your help!


Answer
Ok ,

I would try to disconnect the switch from the mount on the arm by the pedal . Maunally push the brake switch with your finger . On & Off . do the brake lights go on & off . Have a person in the back looking . This switch controls the lights(brake)..Nothing else !
The adjustment on this switch is Very Careful !!! Very Close setting the switch ,touchy!if i might say ..

The pedal going past the point of the switch .Is the pedal going to the floor ? If so you have AIR in the system somewhere ???

You have to start to bleed the system on the bleeder at the right rear wheel , then left rear wheel then right front wheel then the left wheel . Make sure that you see NO AIR coming out of bleeders and that the bleeder do not suck air into the system .. You should only have approx 2 " before the brakes stop , when you push on the pedal . If you have more you have AIR or blow-bye. You replaced the master cylinder , this should have resolved your issues with that .


Let me know ?


Dave G