AAYBS

I started changing all brake pads on our 2008 Mazda 3 2.3L last weekend. I started from rear passenger side, and used a C-clamp that I should not have done. I was able to push the caliper piston back. I felt strange and went online, learned that I just made a mistake, and purchased a set of OMT disc brake pad and caliper service tool kit. I used the OMT force screw to push the rear driver side caliper piston back easily and changed the brake pads. I also replaced the front brake pads as usual.

Wanting to know if I had really damaged the rear passenger side caliper, I used a needle nose piler to unscrew the piston. The piston rotated and came out smoothly. I then tried the OMT force screw to rotate and push the piston back in. But the piston could be rotated easily but not retracting.

I decided to replace a re-manufactured caliper. However, I did not know how to get the parking brake cable slide off a sitting hole on the caliper. One youtuber stated he sprayed WD40 and twisted hard.

A local repair shop said they could fix the caliper and put the brake pads on in an hour. So I had my car towed to their shop. After the fix, they would not explain how they fixed it and the hand brake lever could be pulled up all the way. The shop owner said it was because the parking cable was stretched. The brake pedal felt soft. I drove home cautiously.

Trying to figuring out the hand brake lever problem, I jacked up the rear side and pulled the hand brake lever up till the rear passenger side tire cannot be rotated by hand. At the same condition, I could rotate the rear driver tire easily however. If the rear passenger side parking cable was stretched and longer, why I can rotate the rear drive side tire but not rear passenger tire?

As far as I know the hand brake lever should be between 1 to 6 clicks. Before I can lower clicks to 6, the rear passenger tire already firmly “locked.” How can I do?

I then released the parking brake cable under the center console so that both sides had no tension. The rear passenger side brake pads touched their rotor lightly when rotating while I could see a gap between the rear driver side brake pads and their rotor. I am thinking the equalizer linkage may show how to resolve the issue. But I am not sure how to reach the equalizer linkage under the center console yet. Does anyone know the problem?

How do I know if the rear passenger caliper has been fixed?
Thanks advance for you help and reading.