jcb JS200 Service Manual page 105

Section B
12 - 10
System Diagnosis (cont'd)
Low R-134a Charge
Gauge Readings:
Low Side Gauge - Low.
High Side Gauge - Low.
Other symptoms:
Sight Glass - Bubbles continuously visible.
Diagnosis:
System slightly low on R-134a, due to leak or
incorrect charge.
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.
Poor Refrigerant Circulation
Gauge Readings:
Low Side Gauge - Zero to negative.
High Side Gauge - Low.
Other symptoms:
Receiver-Drier - Frost on tubes from receiver-drier to
evaporator unit.
Diagnosis:
Refrigerant flow obstructed by dirt, receiver-drier
clogged.
Correction:
1. Evacuate A/C system.
2. Replace receiver-drier.
3. Charge system with R-134a.
4. Operate system and check performance.
9803/6400
Body & Framework
Air Conditioning
LOW SIDE (RED)
LOW SIDE - 0.76 bar (0.77 kgf/cm
HIGH SIDE - 8.3 bar (8.5 kgf/cm
LOW SIDE (RED)
Zero to negative
LOW SIDE - -1.0 bar (-1.1 kgf/cm
HIGH SIDE - 5.4 bar (5.5 kgf/cm
HIGH SIDE (BLUE)
Low
2 )(11 lbf/in
2 )(121 lbf/in
HIGH SIDE (BLUE)
2
)(-15 lbf/in
2
)(78 lbf/in
Section B
12 - 10
Low
2 )
2 )
Low
2
)
2
)
Issue 1