Long pedal and brake light on dash

[shift5]

I did the GMT800 MC swap as well as 1-ton front calipers, new pads, new drums, new shoes, new parking brake cables, and all new lines last year. Brakes have been good and issue free, until a couple weeks ago when I suddenly had a long pedal (they do still work, just not as well) and the brake light is going on and off on the dash. Parking brake is not set. Fluid level is full. I hadn't done anything to the brakes to cause a change.

Any ideas?

 

[Chewy11B]

What did you do for a valve?? Sounds like theres an imbalance in pressures front and rear setting off the portioning valve sensor. Should be single wire near master cylinder.

 

[shift5]

What did you do for a valve?? Sounds like theres an imbalance in pressures front and rear setting off the portioning valve sensor. Should be single wire near master cylinder.

Stock ABS so stock proportioning valve.

 

[Supercharged111]

How's the rear adjustment?

 

[shift5]

Adjusted

Wheel cylinders and everything are new as well.

Parking brake works perfect.

 

[Chewy11B]

Something is causing the proportioning valve to lose "balance". The valve is moving with either front or rear bias and causing the light to come on. I would try bleeding brakes and see if there is any air.