Geely CK (2008). Manual part — 79
Geely CK (2008). Manual part - 79
313
Section 7 A/C System Faults Check & Troubleshooting
I. A/C System Faults Check
Inspection shall be made to isolate the fault area and its cause when the fault of A/C system occurs, and then
specific service could be performed. Inspect the whole system before re-using A/C system after a long term
of storage.
First step is initial inspection by direct "see, listen and touch". Test the system with the leak detector if
necessary.
1. Check the Refrigeration System
Under the normal condition, the low pressure pipeline of the A/C refrigeration system takes on a status of low
temperature and the high pressure pipeline takes on a status of high temperature, see Figure 16. Based on
this rule, you can arrive at the initial judgement about the fault area and its cause by touching the refrigeration
system pipeline and elements to feel the surface temperature with your hand.
1
High pressure area: compressor outlet
condenser receiver/drier
expansion valve
inlet, its temperature change trend is from warm
to hot. If the temperature change is not this trend,
but instead some part is extremely hot (e.g.
condenser surface), it indcates that the part is
faulty and the radiation is not good; if some part is
extremely cold (e.g. receiver/drier) or there is frost
(e.g. at expansion valve inlet), it indicates that the
part is faulty and the pipe may be blocked.
2
Low pressure area: expansion valve outlet
evaporator
compressor inlet, its temperature
change trend is from cool to cold, If the
temperature change is not this trend, it indcates that the part is faulty.
3
Compressor: compressor inlet and outlet high & low side shall have apparent feel of temperature difference,
if there is no temperature difference, it indicates that there is leakage in the system and the refrigerant
has leaked.
2. Check the Leakage Area
1
Observe all connecting areas of the refrigeration system or condenser surface for oil stain, if there is oil
stain, it indicates that the the refrigerant is leaking (refrigerant and freezing oil leak simultaneously,
refrigerant volatilize after leakage and leave the freezing oil remained to be oil stain).
2
Apply the soap water to the connecting area, if soap bubble occurs, it indicates that there is leakage.
3
Check with instrument, the common instrument is halogen leak detector. When using the halogen leak
detector for check, the key is the propane flame color depending on which the judgement is made. When
there is no leakage, the flame color remains unchanged, when there is a little leakage, the flame is
greenish, when there is large leakage, the flame is bluish or purple.
Cool
Cold
Hot
Warm
Expension
Valve
Compressor
Evaporator
Condenser
Gas
Gas
Liquid
Liquid
Low Pressure
High Pressure
Figure 16 A/C System Process
→
→
→
→
314
Have a focus inspection on the following area:
a. Each pipe union joint and valve connection.
b. All hose, especially near the pipe union.
c. Compressor shaft seal, front and rear cover, gasket, oil fill plug.
d. Area on the surface of the condenser and evaporator that is scratched, bruised or damaged.
e. Expansion valve inlet and outlet connection and temperature sensor element and the welding position.
3. Check the Refrigerant
Observing from the sight glass, you may understand the refrigerant status and analyze the possible faults:
4. Check Other Parts
Other parts needed to be checked and their check points:
Conditions observed
Possible problems
Clear, no air bubble, A/C emits cool wind
Refrigeration system is normal
Clear, no air bubble, A/C emits warm wind
Refrigerant leaked, there is leakage in the system
Occational air bubble. Expansion valve is frosted There is water mixed in the refrigeration system
Occational air bubble.
Insufficient refrigerant or air mixed in the system
Clear, there is oil stripe on the glass
Outlet is not cold, no refrigerant
Foamy and turbid
Excessive freezing oil
Checked Part
Check Points
There shall be no dirt and rust on the radiator that hinder the heat
exchange;
The radiator surface has no damage, fissure and hidden trouble that may
cause refrigerant leakage.
Electromagnetic Clutch
Clutch operation is normal. When switched on, the compressor shall
operate, clutch can not slip.
Compressor Belt
Belt tension of 250N is normal, belt is not broken and damaged.
Wire
The electromagnetic clutch and blower power cable shall be not damaged
and overheated; the connection shall be reliable, and the protective
grommet through the metal plate shall be kept good and without damage.
Hose
Refrigerant hose and condenser pipe shall be secured and shall not be
damaged by approaching the other overheated parts, moving parts and
sharp parts.
Evaporator Condenser
315
II. A/C System Diagnosis and Troubleshooting
Table 1
Abnormal high pressure of the high pressure pipeline
Abnormal low pressure of the high pressure pipeline
Abnormal high pressure of the low pressure pipeline
Abnormal low pressure of the low pressure pipeline
High and low pressure can not be established
Sight glass has air bubble
Compressor inlet side is frosted
Compressor noise
Abnormal heating on the compressor
Evaporator is frosted
Drier filter ices up
A/C does not refrigerate or the cold air is insufficient
×
×
×
×
Excessive refill of refrigerant
Drain p roper amount of
refrigerant
×
×
×
×
Too little refill of refrigerant
Rep air the gas leak area, refill
p roper amount of refrigerant
×
×
×
×
Refrigerant is leaked all
Rep air the gas leak area, refill
p roper amount of refrigerant
×
×
×
×
×
×
There is non-clotted gas in
the sy stem
Loosen receiver and
condenser inlet connector,
discharge the non-clotted gas
×
×
Excessive freezing oil in the
sy stem
Check comp ressor freezing
oil level, adjust it
×
Excessive high temp erature
of condenser inlet
Perform the check at the
p lace with good ventilation
There is dust in the
condenser core, air channel
within the condenser is
blocked or suffocated
Use compressed air or water
to flush and remove the dirt
on the condenser
Condenser fan faulty or
broken
Check the wiring status and
the fan motor, correct or
rep lace it
×
×
Excessively low temp erature
of condenser inlet
Stop the operation of the
refrigeration sy stem
×
×
×
Drier blocked
Clean
Air channel in the evap orator
blocked or suffocated
Remove the dirt on the
evap orator
Evap orator fan fault, p oor
blower motor wire connection
Check the wiring status and
the fan motor, correct or
rep lace it
×
×
×
There is dirt in evap orator
core
Use the compressed air to
clean the evaporator core
×
×
×
×
×
×
×
Problem Sy mp tom
Possible Cause
Troubleshooting
×
316
A
bnor
m
al high pr
es
su
re
of
the
high pr
es
su
re
pipe
line
A
bnor
m
al low
pr
es
su
re
of
the
high pr
es
su
re
pipe
line
A
bnor
m
al high pr
es
su
re
of
the
low
pr
es
su
re
pipe
line
A
bnor
m
al low
pr
es
su
re
of
the
low
pr
es
su
re
pipe
line
H
igh a
nd low
pr
es
su
re
c
an
not be
e
sta
blis
he
d
Sight gla
ss
ha
s a
ir bubble
Com
pre
ssor inle
t side
is froste
d
C
om
pr
es
sor
nois
e
A
bnor
m
al he
ating on the
c
om
pr
es
sor
Eva
por
ator
is
f
ro
ste
d
Drie
r filte
r ic
es
up
A/C d
oe
s n
ot refrig
erate o
r th
e co
ld
air is in
su
fficien
t
Dirt in the evaporator core, or
poor fit between the
expansion valve sensing unit
and evaporator outlet
Check and correct it
Non-evaporated refrigerant
steam enters into compressor
Service the evaporator and its
components such as fan
expansion valve opening is
excessively big or faulty,
refrigerant supply is
excessive
Adjust the expansion valve,
check the sensing unit and the
evaporator outlet for fitness,
replace it as necessary
×
×
Expansion valve opening is
too small
Adjust expansion valve
×
×
×
×
Expansion valve fault, spinal
corrosion or leakage
Replace expansion valve
×
×
×
The refrigerant pipeline
between the expansion valve
sensing unit and the
expansion valve is damaged or
broken
Check and replace the
expansion valve and pipeline
×
×
Expansion valve blocked by
ice or dirt
Recycle the refrigerant,
remove and clean the
expansion valve, use the
vacuum pump to drain the
water in the system and then
refill the refrigerant
×
Refrigerant pipeline blocked
Disassemble and check the
part
×
Compressor solenoid clutch,
bearing and pulley wear
Check and replace concerned
worn parts
×
×
×
×
×
×
Compressor reed is damaged,
exhaust valve leaks
Check and replace the
compressor
×
Compressor inlet blocked
Check and clean
×
×
Drive belt loose or broken
Replace or replace it
×
Excessively low temperature
in the vehicle compartments
Adjust the selection switch
×
×
×
×
System pipeline leaks
Check the leak area, refill
proper amount of refrigerant
×
×
×
Problem Symptom
Possible Cause
Troubleshooting
×
×
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