Thread: Brake troubles

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I have the same rear brake calipers, I remembered something "specific" to the installation, here it is off MPB instructions, give this a try and let us know.
WARNING
FOR YOUR REAR BRAKES TO OPERATE
YOU MUST ADJUST THE REAR CALIPERS
When installing rear disc brakes with calipers that have an internal parking brake you must adjust or set the calipers
when installing. Failure to do so will prevent you from getting a firm pedal and you will have no rear brake function. You
must also set the parking brake every time you park to keep the calipers adjusted.
The caliper piston is adjusted outward by turning the nut on the lever or by cranking the lever. This ratchets the caliper
piston outward moving the pads closer to the rotor. If you do not do this the rear calipers will take up brake fluid but the
pads will never squeeze the rotor sending the pedal to the floor.
Only peform this adjustment with the caliper and rotor installed on the car. Start by spinning the rotor. Crank the lever
and spin the rotor again to see if there is any drag. Continue cranking the lever until there is a slight drag on the rotor.
Attach the parking brake cable. The caliper should now be adjusted. Repeat on the other side
"One of the biggest advantages of a disc type brake is that it has a fool proof self adjuster. Not so with the rear disc GM! The
rear calipers adjust off of the parking brake. The parking brake is incorporated into the caliper. You MUST set the parking
brake every time you park your car! Not many people do that nowadays because it is much easier to just put the transmission
in park and walk away! The rear caliper pistons utilize a "one way clutch" or "sprag" inside the caliper piston. When the
parking brake is applied the sprag senses when there is .030 or more clearance between the friction material on the inboard
side. When the distance is at least .030, the sprag turns inside the piston adjusting it out and keeping the rear brakes adjusted.
If you are not setting your parking brake with this setup EVERY time you park your car then two things will happen. #1 -
You will start to lose service brake pedal. #2 - The sprag will seize on the inside of the piston and will never work again.
NEVER buy these calipers from a rebuilder, because rebuilders use the old piston in most cases and the piston is the reason
the calipers were changed to begin with! Master Power Brakes uses only NEW calipers for this application! Also, when
replacing rear pads on these calipers, GM says to "get into the vehicle after you have installed the pads and apply the parking
brake 60 times". The short cut around this is to adjust the brakes out by unhooking the parking brake cable at the lever
and adjusting the pistons out using the parking brake lever and a .030 feeler gauge between the inboard pad and the rotor.
Then get in the vehicle and pump the parking brake 2-3 times."
Detailed instructions at http://www.mpbrakes.com/docs/orig-gu...STRUCTIONS.pdf