pipes and joints at the low pressure end. Touch the high pressure area, especially the metal parts at
the high pressure end, such as compressor’s exhaust pipe, condenser, stock fluid dryer and etc, and
find these sections are hot. Be care! If you touch these positions and find that your hand is hot but
doesn’t feel burning, it is normal; and if your hand feels hurning, check whether the condenser is in
the good cooling conditio, the surface of condenser is clean without foreign materials, and etc.
If your hand feels that the temperature is not high at the high pressure end, it indicates that the
coolant level is low; and if there is no temperature which can be felt by your hand, it indicates that
the coolant fully leaks.
If the frosting symptom or water dews can be found on the fluid reservoir, it indicates that the
dessicant is broken and blocks the pipe from which the coolant flows and the temperature of high
pressure area at the front end of this reservoir is very high. In this case, solve the clogging problem
A.S.A.P, replace it with a new dryer and clean the system at the same time.
The temperature of the expansion valve is special when you feel it by hand: its coolant inlet joint is
hot while its outlet joint is cold, with some water dews. If the frosting symptom is found at the
outlet of the expansion valve, it indicates that the expansion valve port is clogged. It may be caused
due to either the foreign materials or the ice generated by the moisture which enters into the cooling
system. The trouble must be handled immediately: either clean the system, replace it with a new
dryer and expansion valve, or revacuumize it and remove the moisture.
Touch the low-pressure reservoir and find your hand feels cold, with water dews but without
frosting symptom. If there is the frosting symptom, it indicates that the system has trouble. Find out
the reason. Touch the intake and exhaust pipes of the compressor, and find that the temperature your
hand feels shall be considerably different. If not, it indicates that the coolant has fully leaked; and if
the difference is not big, it indicates that the coolant level is low.
IMPORTANT: When the A/C system is touched by hand, absolutely pay more attention to the
safety, and avoid the injured by the belt and other motion parts.
Fourth, check:
1. Check the tensile force of belt first. The tensile force of new and old belts is different. Even if it is
a new belt, its tensile force may also change considerably after the use of 5 minutes. As a
newly-installed belt, it must be regulated twice: After the first installation of the belt, its tensile
force must be regulated to the specified value; and after it operates for 30 minutes, it must be
regulated for the second time.
2. Check the magnetic clutch
3. Check the A/C blower
4. Check the high/low pressure switch and overheat protector
5. Check the heating system
6. Check the expansion valve
With the check above-metioned, make certain that the A/C system is in good working condition.
24. Check and Replacement of Three Filters
The three filters means the air cleaner, oil cleaner, and gasoline filter. These three filters are checked
and replaced as follows:
Air cleaner
Remove two screws as shown in the figure below with a cross screwdriver, take off the element of
