Weekly Post-Trip Inspection And Maintenance Procedures - freightliner S2 Operator's Manual

Pre- and Post-Trip Inspections and Maintenance
With the air system fully charged to 120
psi (827 kPa), make one full brake appli-
cation and note the air pressure reading
on the gauge. Continue to reduce the air
pressure by moderate brake applications
to a maximum of 90 psi (620 kPa), then
run the engine at governed rpm. If the
time required to raise the air pressure to
120 psi (827 kPa) (from the pressure
noted after one brake application) is more
than 30 seconds, eliminate any leaks or
replace the air compressor before operat-
ing the vehicle.
25.3 Check the air pressure reserve as follows:
With the air system fully charged to 120
psi (827 kPa), stop the engine and note
the air pressure. Then make one full brake
application and observe the pressure
drop. If it drops more than 25 psi (172
kPa), all areas of leakage must be elimi-
nated before operating the vehicle.
25.4 Check the air leakage in the system as
follows:
With the parking brake (spring brake) ap-
plied, the transmission out of gear, and
the tires chocked, charge the air system
until cut-out pressure of 120 psi (827 kPa)
is reached.
With the service brakes released, shut
down the engine, wait 1 minute and note
the air pressure gauge reading. Observe
the air pressure drop in psi (kPa) per min-
ute.
Charge the air system until cut-out pres-
sure of 120 psi (827 kPa) is reached. With
the parking brakes released and the ser-
vice brake applied, shut down the engine,
wait 1 minute and note the air pressure
gauge reading. Observe the air pressure
drop in psi (kPa) per minute.
If leakage exceeds the limits shown in
Table 15.2, repair all areas of leakage be-
fore driving the vehicle.
15.11
Maximum Allowable Service Brake Leakage
Maximum Air Leakage Per Minute
Brakes Released
2 psi (14 kPa)
Table 15.2, Maximum Allowable Service Brake
Leakage
26. Check the operation of the Bendix® Hydro-Max
brake booster, as follows.
26.1 With the ignition off, depress the brake
pedal and listen for the back-up motor to
engage. The operator should also feel the
pedal force relieve and the pedal should
depress easily.
26.2 With the engine running, and the parking
brake released, ensure that the BRAKE
warning indicator light is not on. This is a
dual indicator, and indicates that the park-
ing brake is set, and warns if there is a
Hydro-Max failure condition other than
loss of back-up motor power.
27. Test the service brakes.
When starting to move the vehicle and before
picking up speed, test the brakes with the foot
pedal and parking brake control valve (yellow
knob) to be sure they will bring the vehicle to a
safe stop.
Weekly Post-Trip Inspection
and Maintenance Procedures
1. Inspect the batteries and battery cables.
WARNING
Battery posts, terminals, and related accessories
contain lead and lead compounds, chemicals
known to the State of California to cause cancer
and reproductive harm. To prevent possible per-
sonal injury, always wash your hands after han-
dling battery parts and related accessories.
1.1
Access the batteries. Be sure the battery
hold-down is secure. If it is loose, tighten
the hold-down bolts; if it is broken, replace
it.
Brakes Applied
3 psi (21 kPa)