Brake Light
 

Hi, I put some brake fluid into the rear portion of the master cylinder as it was very low or empty (manual brakes) on my 1972 C-10 and the brake light stays on on the dash now, any thoughts.

Re: Brake Light
 

time to bleed the brakes. Maybe you'll see whwew all the brake fluid is draining out too.

Re: Brake Light
 

Could be MC push rod is knocking your brake light switch out of position while rebounding when brake is released. I've had same trouble on my 80 GMC, and have been totally unable to resolve problem yet. Tried a new MC seemed to help a little, but still have same problem, Duct taped the switch cures the problem, but is not ultimate cure. Marvxyz

Re: Brake Light
 

double check that the prop valve isnt tripped to one side. Check that the brakes work front and back.

Re: Brake Light
 

if one side of the master cylinder was almost empty, then the switch is doing the job it is intended to do.