OPERATOR'S MANUAL

Air System Preventive Maintenance
– 196 – Y53-6027
Medium Duty (R05/09)
Contamination of the air supply system is the major cause of
problems in air-operated components such as brake valves,
wiper motors, and suspension height control valves. To keep
contaminants to the lowest possible level, follow these main-
tenance procedures.
Scheduled Maintenance
Use Table 5, ”Air System Scheduled Maintenance,” to
schedule service operations and air system tests.
Table 5 Air System Scheduled Maintenance
MAXIMUM INTERVALS
TEST EACH WEEK
EACH MONTH
(10,000 mi) (16,000
km)
THREE MONTHS
(25,000 mi) (40,000
km)
SIX MONTHS
(50,000 mi) (80,000
km)
ANNUALLY
(100,000 mi)
(160,000 km)
Air Compressor
•
Air Governor
•
System Leakage
•
Dual Air Brake Treadle Valve
•–or –•
Hand–Operated Trailer Brake Valve
•–or –•
Tractor Parking Valve
•
Parking Brake Valve
•
Trailer Air Supply
•
Tractor Protection Valves
•
Relay Valve
•
Spring Brake Inversion Valve
•
Automatic Limiting Valve
•
Single Check Valves
•
Double Check Valves
•
Stop Light Switch
•
Low–Pressure Wig Wag
•
Low–Pressure Switch
•