Chery T21 2014 Service Manual page 1389

ON-VEHICLE SERVICE
On-vehicle Inspection
HINT:
The A/C refrigerant lines and hoses are used to transfer refrigerant among the A/C system components. Any
twist or bent in the refrigerant lines and hoses will reduce the performance of A/C system and refrigerant flow
in system.
There remains high pressure in refrigerant when the A/C compressor assembly is operating. It is necessary to
ensure that each connecting part in A/C system is sealed well. Check all the system lines at least once a year
to ensure that they are in good condition and properly routed. The refrigerant lines and hoses cannot be
repaired and must be replaced if leakage or damage exists.
1. General inspection
a. Check if there exists any oil or dust in each joint of the A/C line. If this occurs, there may exist leak.
b. Check if the surface of condenser is dirty and the fins are deformed.
c. Check for harsh noises while the compressor assembly is operating normally.
d. Temperature difference should be noticeable by feeling the intake line and exhaust line of compressor
assembly with hand. Normally, the intake line is cool while the exhaust line is hot. Feel the temperature
of intake duct and exhaust duct of condenser with hand. Normally, the temperature of intake duct is
higher than that of exhaust duct. Feel the temperature difference between expansion valve inlet and
outlet line with hand. Normally, the expansion valve inlet line is hot while the outlet line is cool, and
temperature difference is noticeable between both.
2. Using the pressure gauge set, check the refrigerant pressure.
a. Connect the manifold pressure gauge set. After the following conditions are met, read the pressure on
pressure gauge. Measurement conditions are as follows:
 Inner/outer circulation switch is in outer circulation position.
 Engine runs at approximately 2000 rpm.
 Adjust the temperature knob to MAX. COOL.
 Blower speed control switch is in highest band.
 Turn on the A/C switch.
Observe the pressure value on the pressure gauge. In normal condition, the pressure of low pressure side
is 0.15 - 0.20 MPa and the pressure of high pressure side is 1.3 -1.7 MPa.
Compressor Assembly Noise Inspection
When checking noise related to A/C system, you must first know the conditions under which the noise occurs.
These conditions include: weather, vehicle speed, engine speed, engine temperature and any other special
conditions. Louder noises during A/C operation can often mislead someone. For example, what sounds like a
failed bearing, may be caused by loose bolts, mounting brackets or a loose compressor assembly.
CAUTION
 A/C compressor assembly must be replaced if any abnormal compressor assembly noise is heard.
 Noise may occur from the drive belt at different engine speeds, and you may mistake it for a noise from
A/C compressor assembly. The noise occurs when the compressor assembly operates at the maximum
displacement, and it will not occur at the minimum displacement.
1. Select a quiet place for testing.
2. Duplicate the customer's feedback information as much as possible.
3. Turn the A/C system on and off several times to clearly identify the compressor assembly noise.
Chery Automobile Co., Ltd.
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