Bentley Volkswagen.Golf.Jetta.R32.Official.Factory.Repair.Manual.1999-2005

Pressures, checking on vehicles
Página 13 de 33
specification
- High pressure increases above
specification
- Low pressure quickly drops to
value in graph or below,
- Required cooling output is not
attained.
Note:
- If operation is not OK after
refrigerant circuit has been
flushed, expansion valve must be
replaced.
Possible deviation from
specification
- High and low pressure normal at
first
- After some time, high pressure
increases above specification and
low pressure drops to value in
graph or below
- Required cooling output is no
longer attained.
Note:
- Always replace receiver for this
malfunction.
Possible deviation from
specification
- Constriction or obstruction in
refrigerant circuit
- Expansion valve malfunctioning
Possible cause
- Expansion valve malfunctioning
- Moisture in refrigerant circuit
Possible cause
- Run hand over refrigerant circ
to check for differences in
temperature
- If difference in temperature is
found at one component:
- If hose or pipe is kinked or
constricted, replace this
component.
- In the event of an obstruction
flush refrigerant circuit with
compressed air and nitrogen a
replace expansion valve
- If no malfunction can be found
- Flush refrigerant circuit with
compressed air and nitrogen.
- Repeat test.
Corrective action
- Examine expansion valve for
or corrosion; replace if necessa
- Flush refrigerant circuit with
compressed air and nitrogen.
Corrective action
- High pressure normal or too high - Too much refrigerant in circuit - Extract refrigerant from
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13/2/2005