Engine JAC HFC4DA1-2C. Instruction - page 96
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Diagnosis and Testing
Refrigerant recovery
5.
The refrigerant recovery machine shall start to
recover refrigerant and lubricating oil from A/C
system, which respectively flows into a fluid
reservoir and a removable oil reservoir.
6.
Refrigerant recovery machine shall drain all
refrigerant out of A/C system, achieving partial
vacuum of A/C system with pressure at about 34
kPa (10 Hg).
7.
Once partial vacuum is realized, it is recommended
to turn off the refrigerant recovery machine and
two manual valves and record the pressure
readings. If the vacuum reading rises up to positive
pressure in 2 min, there is still surplus refrigerant
(after boiling) in the receiver drier; therefore, you
should continue to execute the reclaimer until no
obvious positive pressure rise occurs.
8.
Check the oil reservoir for oil recovery and record
the recovered volume, for the same volume of oil
shall be added into A/C system later.
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Diagnosis
Diagnosis
Diagnosis
Diagnosis and
and
and
and Testing
Testing
Testing
Testing
A/C
A/C
A/C
A/C System
System
System
System Performance
Performance
Performance
Performance Table
Table
Table
Table
Engine
speed
(r/min)
Relative
humidity
(%)
Ambient air
temperature
Temperature of central
air vent
Pressure at low-pressure
side of pressure gauge
Pressure at high-pressure
side of pressure gauge
°F
℃
°F
℃
psi
kPa
psi
kPa
Idling
speed
20
59
15
37
3.00
27
162
142
943
68
20
37
3.00
31
185
168
1106
77
25
40
4.64
36
209
191
1296
86
30
47
8.60
42
236
225
1494
95
35
54
12.49
50
265
266
1653
104
40
62
16.45
58
300
304
1864
113
45
69
20.47
63
334
323
2155
40
59
15
37
3.00
25
171
139
956
68
20
38
3.50
28
197
164
1129
77
25
44
6.79
32
222
192
1323
86
30
52
11.27
36
252
209
1445
95
35
61
15.94
42
288
248
1709
104
40
69
20.76
48
329
279
1925
113
45
77
25.18
54
375
306
2110
60
59
15
37
3.00
26
177
140
966
68
20
40
4.47
30
205
166
1146
77
25
48
8.92
34
233
192
1326
86
30
57
13.93
39
269
215
1480
95
35
66
19.11
45
310
249
1718
104
40
76
24.59
52
358
300
2072
113
45
86
29.82
59
406
318
2196
80
59
15
37
3.00
27
186
142
976
68
20
43
6.11
31
214
168
1160
77
25
52
11.15
36
250
191
1320
86
30
62
16.95
42
289
225
1551
95
35
74
23.23
50
342
266
1833
104
40
85
29.27
58
398
304
2096
113
45
96
35.65
63
436
323
2226
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Diagnosis
Diagnosis
Diagnosis
Diagnosis and
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Testing
Testing
Testing
A/C
A/C
A/C
A/C System
System
System
System Performance
Performance
Performance
Performance Table
Table
Table
Table
℃
℉
kPa
psi
℃
℉
kPa
psi
Definition: This table lists the pressure of refrigerant 134a under different temperature. For example, under room temperature of 26.6
℃ (80°F), the pressure of refrigerant reservoir reaches 595.6 kPa (86.4 psi). If the refrigerant is heated up to 51.6℃ (125°F), the
pressure shall rise up to 1278.8 kPa (185.5 psi). You can also determine the boiling point of refrigerant 134a based on different
pressure. For example, under the pressure of 188.2 kPa (27.3 psi), the boiling point of refrigerant R134a is 0℃ (32°F).
15.5
60
392.3
56.9
-23.3
-10
12.4
1.8
18.3
65
438.2
63.6
-20.5
-5
27.0
3.9
21.1
70
487.3
70.7
-17.7
0
43.2
6.3
23.8
75
539.7
78.3
15.0
5
60.8
8.8
26.6
80
595.6
86.4
-12.2
10
80.1
11.6
29.4
85
655.1
95.0
9.4
15
101.3
14.7
32.2
90
718.5
104.2
-6.6
20
124.3
18.0
35.0
95
785.6
113.9
-3.8
25
149.4
21.7
37.7
100
856.9
124.3
-1.1
30
176.6
25.6
40.5
105
932.3
135.2
0.0
32
188.2
27.3
43.3
110
1012.1
146.8
1.6
35
206.2
29.9
46.1
115
1096.4
159.0
4.4
40
238.0
34.5
48.8
120
1185.2
171.9
7.2
45
272.5
39.5
51.6
125
1278.8
185.5
10.0
50
309.5
44.9
54.4
130
1377.3
199.8
12.7
55
349.4
50.7
60.0
140
1589.6
230.5
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Diagnosis
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Diagnosis
Diagnosis and
and
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Testing
Testing
Testing
A/C
A/C
A/C
A/C system
system
system
system performance
performance
performance
performance diagnosis
diagnosis
diagnosis
diagnosis
1.
Air heater performance diagnosis.
Step
Operation
Yes
No
1
Whether or not to conduct this diagnosis based on “ symptoms ” or
instruction of other diagnosis tables?
Go to Step 2.
—
2
①Start the engine.
②Let the engine idling.
Does the engine temperature reach normal operating temperature?
Go to Step 3.
Go to Step 9.
3
①Let the engine idling.
②Select “FLOOR” mode.
③Set the minimum speed of blower.
④Set the warmest temperature.
⑤Sense the temperature of inlet and outlet hoses at the heater core.
Is the inlet hose of heater warmer than the outlet hose?
Go to Step 7.
Go to Step 4.
4
①Place the temperature gauge at the central air vent.
②Fix the temperature gauge onto the outlet hose at the heater core.
③Set the maximum speed of blower.
④Set the warmest temperature.
⑤Record temperature at the position listed below:
Central air vent on instrument panel.
Outlet hose at the heater core.
⑥Compare the recorded temperatures.
Are these two temperatures nearly the same?
Go to Step 5.
Go to Step 6.
5
①Check the following parts of vehicle for cold air leak and conduct
relevant maintenance:
Front shield plate.
Internal circulation damper.
Air heater, ventilation and A/C system module housing.
②Conduct necessary maintenance.
Is the maintenance finished?
Go to Step 10.
—
6
①Check the operation of temperature damper.
②Conduct necessary maintenance.
Is the maintenance finished?
Go to Step 10.
—
7
①Shut down the engine.
②Backflush the heater core.
③Start the engine.
④Select “FLOOR” mode.
⑤Set the minimum speed of blower.
⑥Set the warmest temperature.
⑦Sense the temperature of inlet and outlet hoses at the heater core.
Is the inlet hose of heater warmer than the outlet hose?
Go to Step 8.
Go to Step 10.
8
Replace the heater core.
Is the maintenance finished?
Go to Step 10.
—
9
Troubleshoot too low engine temperature.
Is the maintenance finished?
Go to Step 10.
—