DeVille Concours V8-4.6L VIN Y (1995)
Refrigerant: Service and Repair
Evacuating the System
With Vacuum Pump
Vacuum pumps suitable for removing air and moisture from A/C systems are commercially available. A specification for system pump-down used
here is 28-29 1/2 inches vacuum. This reading can be attained at or near sea level only. For each 1000 feet of altitude this operation is being
performed, the reading will be 1 inch vacuum lower. As an example, at 5000 feet elevation, only 23-24 1/2 inch of vacuum can be obtained. The
system must be completely discharged before it can be evacuated. Damage to vacuum pump may result if pressurized refrigerant is allowed
to enter.
1. With hand gauges connected into system, remove cap from vacuum hose connector. Install hand gauge manifold center hose to vacuum pump
connector. Open low side gauge manifold hand valve only.
2. Ensure low side gauge is calibrated correctly. It should be reading zero. If not, adjust calibration.
3. Evacuate system with the vacuum pump until the low pressure gauge reads at least 28 inches of vacuum. Continue evacuating system for an
additional 15 minutes for routine system servicing or 20 to 30 minutes, if any parts have been replaced.
4. When system evacuation is complete, close low side gauge manifold hand valve, then turn vacuum pump off.
5. Check ability of system to hold vacuum. Watch low side gauge to see that gauge does not rise at a faster rate than 1 inch vacuum every 4 to 5
minutes. If low side gauge rises at too rapid a rate, install partial charge and leak test. Evacuate system again.
6. If system holds vacuum, charge system with refrigerant.
Using Charging Station
A vacuum pump is built into the charging station and is constructed to withstand repeated and prolonged use without damage. Complete moisture
removal from the system is possible only with a vacuum pump constructed for the purpose. The system must be completely discharged before it
can be evacuated. Damage to the vacuum pump may result if pressurized refrigerant is allowed to enter.
1. Connect hose to vacuum pump, if system was discharged through charging station.
2. Open low side gauge hand valve of charging station.
3. Connect station into 110 volt current.
4. Turn vacuum pump on according to instructions for specific station being used.
5. Evacuate system with the vacuum pump until the low pressure gauge reads at least 28 inches of vacuum. Continue evacuating system for an
additional 15 minutes for routine system servicing or 20 to 30 minutes, if any parts have been replaced.
6. Close low side gauge hand valve, then turn vacuum pump off.
7. Check ability of system to hold vacuum. Watch low side gauge to see that gauge does not rise at a faster rate than 1 inch vacuum every 4 to 5
minutes. If low side gauge rises at too rapid a rate, install partial charge and leak test. Then evacuate system again.
8. If system holds vacuum, charge system with refrigerant.
