3-11. Front and rear winch drum brake adjustment
General. The front and rear winch drums are equipped with band brakes, controlled by air pressure from
operator's console. The leading dead end of band is connected to hoist bed and lagging end is connected to brake
actuating arm. Each brake band is set for parking by a spring inside the air chamber connected to brake arm. Air
pressure is required to compress spring and release parking brake. Parking brake is set even if air pressure is lost. The
second part of the chamber uses air pressure to operate the same piston to move actuating arm and apply brake. This
arrangement allows for smooth brake applications during winching operations.
Open front and rear drum brake band covers as illustrated in figure 3-6.
Inspect brake bands for out-of-round condition, uneven pad wear, and contact over at least 85% of drum
surface. If brake band fails this visual inspection, refer problem to your supervisor as brake repair may be required.
Refer to figure 3-7; apply and release brakes and measure crank travel from released to set position. If
crank travel approaches 2 inches, brake requires adjustment.
Figure 3-6. Front and Rear Brake Drum Covers.