Trailer air system pressure must be ± 5 psi
(862 ± 34 kPa) to begin troubleshooting
the brake system. If the air system
pressure cannot be maintained, refer
to Air System Troubleshooting.
Air lines and valves listed in this
troubleshooting procedure are illustrated
and located in FO-2.
Inspect air lines 2254, 2620, and
fittings for crimps.
(1) If air hose(s) or fittings are
crimped, repair or replace air
hose(s) and fittings (see
(2) If air lines and fittings are not
crimped, air lines and