Suzuki Samurai 1986 Service Manual page 396

The distance the lever (1) moves corresponds to
the amount of wear. In accordance with the
lever (1) movement, the fan-shaped ratchet (2)
also moves, for they are assembled as a unit. The
lever (1) and ratchet (2) remain in the positions
as they moved until the shoe-to-drum clearance
becomes even larger.
When the brake pedal is released, the brake shoe
is allowed to move back by the amount of
clearance "B" by means of the return spring. In
this way, the brake shoe-to-drum clearance is
automatically adjusted constant every time the
brake pedal is depressed.
The brake shoe-to-drum clearance "B" corre-
sponds to 0.6 - 0.8 mm (0.0236 - 0.0315 in.)
in terms of the brake drum diameter A tf A'.
And the amount adjusted by one notch of the
ratchet corresponds to 0.20 mm (0.008 in.) in
terms of the brake drum diameter A - A'.
The spring provided in the wheel cylinder
prevents the piston from moving back more than
the specified brake shoe-to-drum clearance.
Fig. 19-11
19-10