Flashing brake light

[Alfredo7474]

I have a 1990 gmc sierra 5.7 k1500. My brake light started flashing. My brake fluid is good and my brakes work perfectly. It flashes 8 times fast and on the 9th is a long one. If it’s nothing serious I’ll just take out the light from the cluster.

 

[Schurkey]

The "BRAKE" light serves three purposes.
1. Safety warning that the two halves of the brake hydraulic system have different pressure--typically one side has "no" pressure.

2. Safety warning that the park brake is "on".

3. Safety warning that the RWAL
is unhappy. Your flashing light is telling you the ABS code it has stored.

For ****'s sake, DO NOT take the bulb out. Diagnose and fix the RWAL.

Download the service manual set for your vehicle from the links in the "Sticky Threads" section of this forum.