New Vehicle Break-In - Mack Granite GU Series Operator's Handbook Manual

OPERATION 115
• Apply service brakes. After initial drop, pressure should hold steady, or
increase slightly, with engine at idle.
• Check slack adjusters and chamber pushrod travel.
• Check steering wheel for excessive free play.
• Check for loose items in the cab. Secure them if necessary.
Step 16: Before Leaving the Parking Area
• Remove chocks from the wheels.
• Test trailer hook-up by slowly pulling while applying the trailer brakes with
the trailer brake hand control valve.
• Test the service brakes before leaving the parking area.
• Test parking brakes by stopping on a 20% grade and applying the parking
brakes. The parking brakes shall hold the combined vehicle and trailer without
moving.

New Vehicle Break-In

To ensure many years of reliable, trouble-free , the following break-in
procedures are recommended:
Note: Oil change, filter change and chassis lubrication are no longer required at the
4,828 km (3,000-mile ) vehicle break-in interval.
Refer to the preventive maintenance schedules outlined in the Maintenance
and Lubrication Manual (21394653) for recommended lubrication change
intervals for the following items:
• Gear oils (transmission, rear axle carrier[s], front drive axle carrier, transfer
case, flywheel PTO)
• Engine oil
• Oil filters
• Fuel filters
• Coolant conditioner
Note: It is important that components be filled with lubricants meeting the
specifications as given in the Maintenance and Lubrication Manual (21394653)
Note: When checking oil levels, the vehicle must be parked on level ground, and
the units at normal operating temperature. Components must be filled to the correct
level. DO NOT OVERFILL.