Section V UNIT MAINTENANCE PROCEDURES
4-9 GENERAL MAINTENANCE PROCEDURES.
This section describes general procedures that apply to all maintenance tasks detailed in this manual. To avoid
repetition, these general procedures will not be repeated elsewhere in the manual.
4-9.1 General Removal and Disassembly Instructions.
Before removing any item, refer to the troubleshooting table. This ensures that faults are isolated to a particular
Work areas must be kept clean. This avoids contamination of internal parts. This is especially true for areas
where control valves, cylinders, or other hydraulic or air system parts are disassembled.
De-energize and Depressurize
Before removing any part of electrical, hydraulic, pneumatic, or foam systems ensure the system is not energized
or pressurized (e g disconnect batteries or relieve all pressure from air system by opening drain valves). Ensure
that all controls are in the OFF position before starting any removal procedure.
Study the task description before disassembling or removing any item. This reduces job time as all tools and
equipment will be available and procedures will have been noted.
Ensure there is sufficient clearance to remove or disassemble a particular part. Disassemble adjacent parts as
necessary to provide reasonable working clearance.
Use a hoist, jack, or other aid when lifting heavy parts. Lifting devices should be positioned and attached to the
part to remove all strain from mounting hardware before part is removed. Never work under a part which is
supported only by a lifting device. Always support that part on maintenance trestles or other supports before
In certain cases it will be necessary to raise the truck so that all tires clear the ground. The following procedure
describes a safe method of lifting the truck.
Drain water tank to reduce truck weight.
Park truck on level, hard surface. Position gear selector to N (neutral) and apply parking brakes.
Chock wheels of opposite axle.