Ford manual is available at
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It reads....
Section 12-03A: Air Conditioning System, Manual A/C-Heater, Aerostar
1994 All Aerostar Vehicles Workshop Manual
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Installation
Transfer the old A/C compressor clutch to the new A/C compressor.
NOTE: If installing a new A/C compressor, lubricate with 30 ml (one fluid ounce) of clean compressor oil, and fill to system capacity. If installing a compressor after repairing for leaks, add the same amount of oil that was removed from the old compressor. If that amount is 90 ml (three ounces) or less, add an additional two ounces.
Remove the A/C compressor bolts and stud from the power steering pump and A/C compressor bracket.
Remove the A/C compressor from the power steering pump and A/C compressor bracket.
NOTE: When replacing an A/C compressor (19703) use original manifold bolt from removed A/C compressor to attach A/C manifold and tube to new A/C compressor. DO NOT USE THE SHIPPING CAP BOLTS.
Position A/C compressor in the power steering pump and A/C compressor bracket.
Install the A/C compressor bolts and stud. Tighten the A/C compressor bolts and stud to 21.2-28.8 Nm (15.6-21 lb-ft).
Install power steering hose bracket on A/C compressor stud. Tighten power steering hose bracket nut to 7.6-10.4 Nm (67-92 lb-in).
Install electrical connector to A/C clutch (2884).
Install drive belt.
Install the power steering oil reservoir bolts. Tighten the power steering oil reservoir bolts to 7.6-10.4 Nm (67-92 lb-in).
Install A/C manifold and tube. Refer to the procedure in this section.
Charge the A/C system. For additional information, refer to Section 12-00.
Operate A/C system to determine if A/C system is operating properly.
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In Section 12-00: Climate Control System, Service
1994 All Aerostar, Ranger and Explorer Vehicles Workshop Manual
SERVICE PROCEDURES
Adding Refrigerant Oil
R-134a A/C System
The R-134a A/C system FS-10 compressor uses a unique high-quality refrigerant oil (F2AZ-19577-AA), Motorcraft Part Number YN-12 or an equivalent refrigerant oil meeting Ford specification WSH-M1C231-B. An oil charge of 207 ml (7 oz) is used in a new system. It is extremely important that only the specified type and quantity of refrigerant oil be used in the FS-10 compressor. If there is a surplus of oil in the system, it will circulate with the refrigerant, reducing the cooling capacity of the system. Using too little oil or oil not meeting the Ford specification will result in poor lubrication of the compressor.
When replacing a component of the refrigerant system, the procedures in this section must be followed to make sure that the total oil charge in the system is correct after the new part is installed.
When the compressor is operated, oil gradually leaves the compressor and is circulated through the system with the refrigerant. Eventually, a balanced condition is reached in which a certain amount of oil is retained in the compressor and a certain amount is continually circulated. If a component of the system is removed after the system has been operated, some oil will go with it. To maintain the original total oil charge add oil as required to the new replacement part.
The procedures for replacing oil are as follows:
During Compressor Replacement
NOTE: FS-10 compressors shipped as service replacements MAY or MAY NOT contain oil.
NOTE: The suction accumulator-drier and orifice tube should also be replaced when the compressor is replaced.
Prior to installing the replacement compressor, drain the refrigerant oil from the removed compressor into a clean calibrated measuring device.
To drain the oil, place the disk and hub assembly on the old compressor shaft so the shaft can be rotated.
Rotate the shaft by hand six to eight revolutions, while pouring the oil from ports. This effectively empties the compressor of oil.
Record the amount of oil removed from the old compressor.
If the new FS-10 compressor contains oil, drain the refrigerant oil from the new compressor following the procedure in step 1 above.
If the new FS-10 compressor has NO OIL, then the oil draining step will not be necessary.
Matching Oil Quantities
If the amount of oil drained from the old compressor (step 2) is between 85 and 142 ml (3 and 5 oz.), pour the same amount of clean YN-12 refrigerant oil into the NEW compressor.
If the amount of oil drained from the old compressor (step 2) is greater than 142 ml (5 oz.), pour 142 ml (5 oz.) of clean YN-12 refrigerant oil into the NEW compressor.
If the amount of oil drained from the oil compressor (step 2) is less than 85 ml (3 oz.), pour 85 ml (3 oz.) of clean YN-12 refrigerant oil into the new compressor.
NOTE: Replacement of the suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
During Component Replacement
When replacing other components of the air conditioning system, measured quantities of the specified refrigerant oil should be added to the component to make sure that the total charge in the system is correct before the system is operated.
Clean refrigerant oil should be poured directly into the replacement components as follows:
A/C evaporator core (19860): add 90 ml (3 oz).
A/C condenser core (19712): add 30 ml (1 oz).
Accumulator: drain oil from removed accumulator/drier. Add same amount plug 60 ml (2 oz) of clean refrigerant oil to new accumulator.
If any other component such as an A/C evaporator core orifice (19D990) or a hose is replaced, no additional refrigerant oil is necessary unless a hose bursts with a fully charged system. Then, the addition of refrigerant oil may be necessary with the amount to be determined by the technician. The suction accumulator-drier should also be replaced under these circumstances.
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Welcome Visitor! Please take a few seconds and 
.. Not a big leak but I'm sure a good ounce of oil got lost. I didn't want to lose a good charge of oil so I disconnected the high pressure gauge, put in an ounce of oil through the low pressure port (it's sold mixed with one once of R134a so the pressure in the can does the job of charging your system) and went by pressure and air temp... I'm sure I am around the desired charge, and can't do nothing but double check once the 120F summer comes in so, in the meantime I have another story accumulated on my rebuild lol... thanks everyone for your help!!
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