4-37. BLEEDING HYDRAULIC BRAKE SYSTEM (Cont).
PRESSURE FEED FILLER BLEEDING
Install pressure feed adapter in cap (4) hole in master cylinder (5). Connect air pressure hose to adapter.
Air pressure should be maintained between 10-20 psi (69-138 kPa)
cylinder should contain a constant level of brake fluid during bleeding.
Clean bleeder valve (1) and install bleeder tube (2).
Position opposite end of bleeder tube (2) in glass jar (3) partially filled with clean brake fluid.
Do not reuse brake fluid when refilling master cylinder. Use only clean brake fluid to
prevent contamination of brake system.
Loosen bleeder valve (1) 3/4 turn counterclockwise.
Air in hydraulic brake system will appear as bubbles in the brake fluid when expelled
Apply compressed air to master cylinder (5) and expel air from hydraulic brake system. Continue until air
bubbles in brake fluid stop.
Tighten bleeder valve (1) and shut off compressed air. Remove bleeder tube (2) from bleeder valve (1).
Remove air pressure hose and pressure feed adapter from cap (4) hole in master cylinder (5).
Replenish brake fluid in accordance with Chapter 3, Section i and install cap (4).
Uncouple semitrailer from towing vehicle (para 2-11).