TM 9-2320-280-20-2
7-10. SERVICE BRAKE SYSTEM BLEEDING INSTRUCTIONS (Cont’d)
a. Pressure Bleeding
CAUTION
When using a pressure bleeding tank, follow the manufacturer's
instructions for its use. Do not exceed the recommended working
pressure when pressurizing the tank. A tank pressure of 15-20
psi (103, 138 kPa) is sufficient to bleed the brake hydraulic
system. Release all air pressure from the tank after using it.
After refilling pressure bleeding tank with silicone brake fluid,
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2.
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8.
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let tank sit undisturbed for 30 minutes minimum to ensure all
visible as well as minute air bubbles are gone.
N O TE
This procedure covers bleeding at one wheel. Repeat bleeding
task for remaining wheels.
Remove cover from master cylinder (1).
Install pressure tank bleeder adapter (2) to master cylinder (1).
Connect line (3) from pressure tank to adapter (2).
Remove protective cap (5) from bleeder screw (6) on caliper assembly (7).
Connect short piece of hose (8) to bleeder screw (6), and place other end of hose (8) in container 3/4
full of brake fluid.
Open valve (4) on line from pressure tank to master cylinder (1), allowing pressurized brake fluid to
enter system.
Open bleeder screw (6) 3/4 turn and observe brake fluid in container. Close bleeder screw (6) when
brake fluid flows free of air bubbles.
Disconnect hose (8) from bleeder screw (6) and install protective cap (5) on bleeder screw (6).
Close valve (4) on line (3) from pressure tank to master cylinder (1).
Disconnect line (3) from adapter (2).
Remove adapter (2) from master cylinder (1) and install master cylinder cover.
b. Manual Bleeding
N O TE
This procedure covers bleeding at one wheel. Repeat bleeding
task for remaining wheels.
Assistant is required to depress the brake pedal when manually
bleeding brakes while mechanic opens and closes bleeder screw.
1. Remove protective cap (5) from bleeder screw (6) on caliper assembly (7).
2. Connect short piece of hose (8) to bleeder screw (6), and place other end of hose (8) in container 3/4
full brake fluid.
CAUTION
Check the master cylinder fluid level frequently during the
bleeding operation and refill the reservoirs as necessary. Do not
allow the master cylinder to run out of fluid at any time, or
additional air will be drawn into the system.
After adding silicone brake fluid to master cylinder, let cylinder
sit undisturbed for 30 minutes minimum to ensure all visible as
well as minute air bubbles are gone.
7-20
