Reverse Piston Disassembly Note

Set the 2-4 brake drum onto the end cover.
Remove the reverse piston from the 2-4 brake drum by applying compressed air through the fluid passage.
Air pressure

392 kPa {4.0 kgf/cm ² , 57 psi} max.

Fig 1: Applying Compressed Air Through Fluid Passage

Courtesy of MAZDA MOTORS CORP.