If air lines are under high pressure when they are disconnected, they can whip around and cause injury
to personnel. Caution should be exercised when loosening or disconnecting air line fittings.
Truck must be on level ground and wheels must be chocked before parking brake is released.
Otherwise, truck may roll and cause injury to personnel.
Wear safety goggles when performing leakage tests on valves. Failure to do so may result in serious
eye injury due to high pressure air.
(1) Start engine and build pressure
to 125 ±4 psi (861 ±28 kPa)
(2) Turn OFF ENGINE switch.
(3) Disconnect air line 2140 from right
(4) Connect a 0 to 160 psi (0 to 1103 kPa)
gage to air line 2140.
(5) Release and apply PARKING BRAKE.
(a) If there are 125 ±4 psi
(861 ±28 kPa) at air line 2140,
perform Steps (6) through (8)
below and replace relay
spring valve No. 2 (Para 12-17).
(b) If there are not 125 ±4 psi
(861 ±28 kPa) present at air line
2140, relay spring valve No. 2
(6) Apply PARKING BRAKE.
(7) Loosen gage at air line 2140 enough
to allow air to completely leak from
(8) Remove gage and connect air line
2140 to right air chamber.