Stop Screw and O-ring (without ABS/TCS) Assembly Note

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Install the secondary piston and primary piston.
Install the new O-ring onto the stop screw.
Push the primary piston assembly in full.
Install and tighten the stop screw.
Tightening torque

2.0-2.4 N.m {21-24 kgf.cm, 18-21 in.lbf}

Fig 1: Installing Secondary Piston And Primary Piston
Courtesy of MAZDA MOTORS CORP.
Push and release the secondary piston component to verify that it is held properly by the stop screw.