Service Manual

627333-A 5-35
HVAC Testing and Adjusting
HVAC TESTING AND ADJUSTING
TROUBLESHOOTING MACHINE
PREPARATION
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WARNING: Personal injury can result
from contact with refrigerant.
System is always under pressure, even if
engine is not running. Never apply heat to
a charged system.
Refrigerant contact can cause frostbite.
Keep face and hands away to prevent
injury.
Even if gauges indicate no refrigerant in
system, protective goggles must always
be worn when refrigerant lines are
opened.
Always use caution when removing a
fitting and always loosen fittings slowly. If
system is still under pressure, evacuate
and recover refrigerant before removing
fitting.
Personal injury or death can result from
inhaling refrigerant through a lit cigarette
or other smoking method.
Inhaling fumes released from a flame,
contacting with air conditioner refrigerant
gas, can cause bodily harm or death.
Do not smoke when servicing air
conditioners or anytime refrigerant gas
may be present.
Before checking air conditioning and
heating system, move machine to a level
surface and lower all implements to the
ground. Ensure transmission is in neutral
or park and parking brake is engaged.
Keep all other personnel away from unit or
where they are visible.
Before any problem solving procedures are performed,
refer to Testing and Adjusting, Visual Inspection. Make a
visual inspection of the complete air conditioning and
heating system.
• All charging and leak testing must be done in a well-
ventilated area.
• Avoid any physical contact with refrigerant as
contact can cause frostbite.
• Always wear goggles when working on or testing
any part of the air conditioning system.
• Place a clean cloth over any open valve or
connection.
• Never weld, solder or steam clean any charged
components.
• Do not smoke when recovering or recycling
refrigerant, charging, performing a leak test or
flushing the system.
• Do not carry refrigerant drums in cab or expose
them to direct sunlight.
• Dispose of any opened, but unused, oil that is poly
alkaline glycol (PAG). Moisture will contaminate
unused oil and the air conditioning system.