23. Wheel bearings should be cleaned and repacked every 10,000 miles or twice a year (spring and fall). Bearings
should be repacked even with the inside diameter of bearing cups with wheel bearing lubricant.
24. Air brakes should be checked for proper operation before each trip. Make certain air tanks are drained of water
daily if not equipped with an automatic moisture ejector device. At each 50 hour period, check warning buzzer and
automatic spring brakes for operation by releasing air pressure below 70 pounds.
If pressure gage drops over 2 psi per minute with engine stopped, check system for leaks and correct before
Air compressor filter should be cleaned after 250 hours of operation, oiled lightly with
clean engine crankcase oil and reinstalled. Lubricate brake actuating system at all points periodically using a No.
1 NLGI grade of high temperature waterproof grease. Refer to manufacturer's maintenance manual for detailed
25. Wheel lug nuts should be checked for proper torque. Tires should be visually inspected for condition and checked
for recommended cold inflation pressure. Refer to Trouble Shooting Section for tire wear indication of improper
wheel alignment and to the Service and Maintenance Manual for adjustment procedures.
IMPORTANT: ALL OF THE TANDEM FRONT END AXLE ALIGNMENT ADJUSTMENTS MUST MATCH OR ERRATIC
STEERING AND RAPID TI RE WEAR WILL RESULT.
Toe-in measurements should be 1/16 in. to 1/8 in., camber 1° positive and caster 2° positive. When rear tire
changes are indicated on the through drive type tandems, it will be necessary to replace them with matched tires
throughout (within 3/4 in. of the same rolling circumference at the same tire pressure). Mount the two largest tires
on one side of one axle and mount the two smallest on the opposite side of the same axle. Mount the four other
tires on the other axle in the same manner.