Table 3-5. Troubleshooting (Cont)
Test or Inspection
BRAKES AND AIR SYSTEM (CONT)
89. AIR SYSTEM HAS NO EFFECT ON BRAKING (HARD BRAKING).
Step 1. Start engine < Check for low pressure in air tanks by waiting until red
warning light goes out or until dual brake gage indicates pressure of
If dual brake gage indicates 75-106 psi, replace air brake
booster (page 4-295).
If dual brake gage indicates less than 75-106 psi, go to step 2.
Step 2. Stop engine. Check for leaks in air system by observing brake fluid reservoir
air pressure indicator. If reservoir pressure drops suddenly, there are leaks
in air system.
If there are leaks in air system, tighten or replace loose lines
or connectors (pages 4-302, 4-303, 4-304, 4-307, 4-310, 4-313,
4-315, 4-318, 4-320, 4-324, 4-327, 4-329, 4-333). If problem
continues, notify direct support maintenance.
If there are no leaks in air system, go to step 3.
Step 3. Check fluid regulating valve adjustment as follows: