Hi, I have a 95 Chevy Blazer that had a brake line going to the back
of the truck rust out. In the process, the brake warning light came
on. I replace the brake line running to back of the truck, the
distribution block at the rear axle, and the lines running to the
wheel cylinders. I ended up replacing the rear wheel cylinders because
the bleeders were rusted in. I bleed the rear brakes. No air appears
to be coming out of the bleeders any more. The brake pedal is firm but
lower than before, but the brake warning light is still on and I have
no rear brake pressure. Is it possible that the combination valve is
stuck or frozen? Could I still have air in the rear brake system?