Figure 12-32.-Dual disc brake.
lining wear, checking disc wear, and replacing worn
linings and discs.
A bleeder valve is provided on the brake housing
(fig. 12-31) for bleeding the single disc brake. Bleeding
should be performed according to the instructions
contained in the aircraft MIM.
Operational checks are made during taxiing.
Braking action for each main landing gear wheel should
be equal, with equal application of pedal pressure and
without any evidence of soft or spongy action. When
pedal pressure is released, the brakes shouId release
without any evidence of drag. All disc-type brakes must
be checked periodically for lining wear. Excessively
worn linings must be replaced.
Lining wear may be checked by two methods. The
method used depends upon the model of the brake
assembly. Both methods are described later in this
chapter. Before checking the brakes on any aircraft,
always refer to the applicable MIM and use the method
recommended by the aircraft manufacturer.
DUAL DISC BRAKES
Dual disc brakes tire used on aircraft where more
braking friction is desired with lower pressures.
The dual disc brake is very similar to the single disc
type, except that two rotating discs, instead of one, are
used. One model of this brake is shown in figure 12-32.
The unit consists of a housing assembly, a center
carrier assembIy, and two rotating discs. The housing
assembly contains four cylinders, each of which
contains a piston, a return spring, and a self-adjusting
pin. Brake linings (pucks) are attached to each piston, to
both sides of the center carrier, and to the housing
assembly, which makes a total of 16 pucks.
12-37
