Hello! I have a 1984 Cadillac Seville with rear disc brakes & ratcheting calipers. My red BRAKE light is on so I replaced pads & calipers. (Pads badly worn, caliper piston walls pitted). After replacing, I can not seem to get the brakes to work! Can not bleed. I gravity bled them and had fairly good flow. I had someone pump & hold the brakes so I could release the air from lines but noted the pads were not even clamping down on either rotor. Also noted by loostening the bleeder valve nothing came out MOST of the time & every once in a while (especially if you walk away from it for a while) you would get a small spurt. Am I doing something wrong?
The rear pistons don't pump out like the front ones do. You have to stroke the parking brake pedal to work the pistons out. If the cables are rusted tight, use a large channel-lock pliers to work the levers on the calipers back and forth. Until you do that you won't get a solid pedal.
You likely still have another brake problem. The red light turned on for low fluid, the parking brake wasn't fully released, or there was an internal or external fluid leak that caused unequal pressures in the two hydraulic systems.