jcb 4CX Service Manual

10 - 6
Air Conditioning
- System Diagnosis (cont'd)
Air in System
Gauge Readings:
Low Side Gauge - High.
High Side Gauge - High.
Other symptoms:
Sight Glass - Bubbles visible during system
operation.
Pipes - Low pressure pipes are hot to the touch.
Diagnosis:
Air is present in the system, possibly from
inadequate evacuation procedure.
Correction:
1. Evacuate A/C system.
2. Check compressor oil for contamination. Check
compressor for proper oil amount. Correct if
necessary.
3. Charge system with R-134a.
4. Operate system and check performance.
Expansion Valve Improperly Mounted or Heat
Sensing Tube Defective (Opening Too Wide)
Gauge Readings:
Low Side Gauge - High.
High Side Gauge - High.
Other symptoms:
Pipes - Large amount of frost or moisture on low side
pipes.
Diagnosis:
Excessive refrigerant in low side pipes possibly
from expansion valve being opened too wide.
Correction:
1. Leak test system.
2. Evacuate A/C system.
3. Repair system leaks.
4. Charge system with R-134a.
5. Operate system and check performance.
LOW SIDE (Blue) HIGH SIDE (Red)
High High
Section B Body & Framework
9803/3280
Section B
10 - 6
Issue 1
Fault Finding
LOW SIDE (Blue) HIGH SIDE (Red)
High High
LOW SIDE - 2.8 bar (2.8 kgf/cm
2
)(40 lbf/in
2
)
HIGH SIDE - 22.1 bar (22.5 kgf/cm
2
)(320 lbf/in
2
)
LOW SIDE - 3.5 bar (3.5 kgf/cm
2
)(50 lbf/in
2
)
HIGH SIDE - 22.1 bar (22.5 kgf/cm
2
)(320 lbf/in
2
)
50
40
30
30
0
10
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60
70
80
90
100
110
120
350
150
100
500
0
50
200
250
300
350
400
450
A268070
50
40
30
30
0
10
20
60
70
80
90
100
110
120
350
150
100
500
0
50
200
250
300
350
400
450
A268080
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jcb 4CX Specifications

General

Brand	jcb
Model	4CX
Category	Compact Loader
Language	English