Brake Piston Positioning “Clocking”

Brake Piston Positioning “Clocking”

Figure 228 Prior to installing the trumpet arm it is “Imperative” that the brake piston ears be in the correct position. If the piston ears are out of position during reassembly they may break or the piston return springs will not make contact, possibly causing brake drag. Temporarily install the abutment plate on the piston, engaging the cutouts in the abutment plate with the ears on the piston as shown.

Figure 229 Using the dowel pin hole as reference install (2) alignment pins as shown in the 4th and 9th holes from the dowel pin hole.

Figure 230 Measure the distance form alignment pins to eye brows in abutment plate. Turn abutment plate to position the eye brows an equal distance from each pin. Carefully remove abutment plate without disturbing piston position. Perform this procedure on both brake pistons.