1991 FORD FESTIVA air conditioning

Fig. 1: Identifying R
-134a Fittings & Quick Connect Service Couplings
Courtesy of AUDI OF AMERICA, INC.
Underhood A/C Specification Labels
Most R-134a based systems will be identified through the use of Green or Light Blue underhood labels, or with R-134a refrigerant clearly
printed on labels. See Fig. 2 . Some manufacturers will identify R-12 based systems with White, Red, Silver or Gold underhood labels. Before
servicing an A/C system, always determine which refrigerant is being used.
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Fig. 2: Underhood A/C Specification Labels (Typical)

Courtesy of NISSAN MOTOR CO., U.S.A.
Other Means Of Identification
Refrigerant R-134a, when viewed through a sight glass, may have a "milky" appearance due to the mixture of refrigerant and lubricating oil. As
the refrigerant and oil DO NOT exhibit a "clear" sight glass on a properly charged A/C system, R-134a systems have no sight glass.
Audi, Mercedes-Benz and Volkswagen use Green bands/labels on condenser, refrigerant lines, receiver-drier and expansion valve. Lexus A/C
system hoses and line connectors have a groove, a White line and "R-134a" marked on them. See Fig. 3
.

Fig. 3: Identifying R
-134a Hose & Line Connectors (Lexus)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
REFRIGERANT OILS
Refrigerant R-12 based systems use mineral oil, while R-134a systems use synthetic/Polyalkylene Glycol (PAG) oils. Using a mineral oil based
lubricant with R-134a will result in A/C compressor failure due to lack of proper lubrication.
Use ONLY specified oil for the appropriate system and A/C compressor. Always check the underhood A/C specification label or A/C
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compressor label before adding refrigerant oil to A/C compressor/system. See Fig. 2 . The following R-134a refrigerant oils are currently
available.
Lexus
PAG Refrigerant Oil (ND-OIL 8) with 10P/10PA swashplate (piston) compressor. Synthetic Refrigerant Oil (ND-OIL 9) with through-va n e
(rotary vane) compressor.
Mercedes-Benz
PAG Refrigerant Oil (001 989 08 03).
Nissan
PAG Refrigerant Oil (KLH00-PAGR0) with rotary vane compressor. PAG Refrigerant Oil (KLH00-PAGS0) with piston (swashplate)
compressor.
Saab
PAG Refrigerant Oil (40 74 787).
SERVICE EQUIPMENT
Because R-134a is not interchangeable with R-12, separate sets of hoses, manifold gauge set and recovery/recycling equipment are required to
service vehicles. This is necessary to avoid cross-contaminating and damaging system.
All equipment used to service systems using R-134a must meet SAE standard J1991. The service hoses on the manifold gauge set must have
manual (turn wheel) or automatic back-flow valves at the service port connector ends. This will prevent refrigerant from being released into
the atmosphere.
For identification purposes, R-134a service hoses must have a Black stripe along its length and be clearly labeled SAE J2196/R-134a. The low
pressure test hose is Blue with a Black stripe. The high pressure test hose is Red with a Black stripe, and the center test hose is Yellow with a
Black stripe.
R-134a manifold gauge sets can be identified by one or all of the following.
Labeled FOR USE WITH R-134a on set
Labeled HFC-134 or R-134a on gauge face
Light Blue color on gauge face
In addition, pressure/temperature scales on R-134a gauge sets are different from R-12 manifold gauge sets.
SYSTEM SERVICE VALVES
SCHRADER-TYPE VALVES
Schrader valve is similar in construction and operation to a tire valve. When a test gauge hose with built-in valve core depressor is attached,
Schrader stem is pushed inward to the open position and allows system pressure to reach gauge.
If test hose does not have a built-in core depressor, an adapter must be used. Never attach hose or adapter to Schrader valve unless it is first
connected to manifold gauge set.
Refrigerant R-12 Schrader-type valve cores have TV5 thread size. Refrigerant R-134a Schrader-type valve cores use M6 (Metric) threads. R-
134a valve cores can be easily identified by use of "O" rings and external spring. See Fig. 1
.
SERVICE VALVE LOCATIONS
SERVICE VALVE LOCATIONS NOTE:Synthetic/PAG oils absorb m oisture very rapidly, 2.3-5.6% by weight, as com pared to a m ineral oil
absorption rate of .005% by weight.
NOTE:Refrigerant R-12 service hoses will ONLY be labeled SAE J2196.
NOTE:Although sim ilar in construction and operation to a tire valve, NEVER replace a Schrader-type valve
with a tire valve.
VehicleHighLow
Audi(14) (15)
Acura(2) (3)
BMW(4) (5)
Chrysler, Eagle & Mitsubishi
Colt, Mirage & Summit(10) (11)
Colt Vista & Summit Wagon(10) (11)
Diamante(1) (1)
Eclipse & Expo(10) (11)
Galant(10) (11)
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REFRIGERANT RECOVERY/RECYCLING
Refrigerant recovery/recycling equipment is used to remove refrigerant from vehicle's A/C system without polluting atmosphere. To remove
and recycle refrigerant, connect the recovery/recycling system and follow instructions provided with the system.
The removed refrigerant is filtered, dried and stored in a tank within the recovery/recycling system until it is ready to be pumped back into the
vehicle's A/C system. With refrigerant stored in the recovery/recycling system, A/C system can be opened without polluting atmosphere.
Montero(13) (13)
Pickup & Ram-50(10) (11)
Precis(12) (12)
Stealth & 3000GT(1) (1)
Daihatsu(4) (5)
Ford Motor Co.(4) (5)
General Motors & Geo(1) (1)
Honda(4) (5)
Hyundai
Elantra(4) (5)
Excel & Scoupe(12) (12)
Sonata(10) (11)
In fin it i(4) (5)
Isu zu(4) (5)
Jaguar(4) (5)
Lexus(4) (5)
Mazda
B2200 & B2600i(8) (8)
Miata(4) (5)
Navajo(6) (7)
All Others(1) (1)
Mercedes-Benz(4) (5)
Nissan(4) (5)
Porsche
1989-92 Carrera 911 2/4(8) (8)
Saab(8) (8)
Subaru
Legacy & Loyale(4) (5)
SVX(9) (9)
Suzuki(4) (5)
Toyota
Pickup & 4Runner(13) (13)
Supra(10) (11)
All Others(4) (5)
Volkswagen(4) (5)
Volvo(4) (5)
(1)Information is not available from manufacturer.
(2)On high pressure line (near receiver-drier on Legend; on receiver-drier on Vigor). Use High-Side Adapter (J-25498).
(3)On low pressure line (near right side of condenser on Legend).
(4)On high pressure (discharge) hose/line.
(5)On low pressure (suction) hose/line.
(6)On high pressure line, between compressor and condenser.
(7)On suction accumulator/drier.
(8)On low and high pressure hoses, behind compressor.
(9)On receiver/drier and low pressure hose (near compressor).
(10)On compressor high pressure (discharge) hose.
(11)On compressor low pressure (suction) port.
(12)On compressor discharge hose and accumulator.
(13)On compressor discharge and suction ports.
(14)Remove high pressure cut-out switch to expose high pressure service valve.
(15)Remove low pressure switch to expose low pressure service valve.
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NOTE:Separate sets of hoses, gauges and refrigerant recovery/recycling equipm ent MUST be used for R-12
and R-134a based system s. DO NOT m ix R-12 and R-134a refrigerants, as their refrigerant oils and
desiccants are NOT com patible. On system s with R-134a refrigerant, use Polyalkylene Glycol (PAG)
wax-free refrigerant oil.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00039025
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A/C SYST EM PRECAUT IONS
A/C GENERAL SERVICING A/C System Servicing cautions
BEFORE OPENING THE SYSTEM
Before disconnecting any lines or fittings, the system must be completely discharged using approved refrigerant recovery/recycling equipment.
DISCHARGING A/C SYSTEM
1. Remove service valve caps and install gauges. For high side gauge hose, Adapter (D81L-19703-A) must be used to connect to high side
service valve.
2. Place open end of center hose in garage exhaust outlet or in a well ventilated area. Slightly open low side gauge valve and let refrigerant
escape slowly without loosing refrigerant oil.
3. When system is nearly discharged, using approved refrigerant recovery/recycling equipment, open high side gauge valve to release any
pressure trapped in compressor. Close valves immediately after discharging to prevent entry of moisture.
DISCONNECTING LINES & FITTINGS
1. After system is discharged, using approved refrigerant recovery/recycling equipment, carefully clean entire area around coupling nut to
prevent dirt entering system. Always use two wrenches to avoid twisting or distorting lines and fittings (hold fitting with one wrench
while loosening coupling nut with second wrench).
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT-1056) to open or close. See procedure under Connecting
Lines and Fittings.
3. Cap or plug all LINES and FITTINGS immediately to prevent entry of air and moisture into system. Do not remove these caps until
connections are being made.
COMPONENT REPLACEMENT
When components are replaced, system oil level must be adjusted. Add refrigeration oil to replacement component. See Compressor oil Check
article, as well as COMPONENT OIL REPLACEMENT QUANTITIES chart under A/C SYSTEM SPECS article in this section.
USING R-12 REFRIGERANT - SAFETY PRECAUTIONS
1. Always work in a well-ventilated, clean area. Refrigerant (R-12) is heavier than oxygen, and will displace oxygen in a confined area.
Always wear eye protection when working around air conditioning systems and R-12. The system's high pressure can cause severe injury
to eyes and skin if a hose were to burst. R-12 evaporates quickly when exposed to atmosphere, freezing anything it contacts.
2. Use care when handling refrigerant containers. DO NOT drop or strike containers or expose refrigerant containers to excessive heat.
Containers must never be heated more than 125°F (52°C). Never expose R-12 directly to open flame.
USING INDIVIDUAL R-12 CANS
Disposable refrigerant cans (referred to as one pound cans) have a flat type seal or a screw type seal, and proper can tap must be used for each
type. Be sure sealing gasket on can tap is in good condition. A proper safety can tap will prevent refrigerant from flowing back into open can,
as tap has a one-way flow control.
MULTI-CAN DISPENSING VALVES
A multi-can dispensing valve allows attachment of several cans of refrigerant, and is a good substitute when a bulk container is not available.
Cans are installed onto each leg of multi-can dispensing valve in the same manner as the individual cans, and each leg has its own can tap.
CAN TAP INSTALLATION FLAT TYPE SEAL CANS
On cam-lock or one-piece can taps, first turn the handle outward to the fully open position. Securely engage locking lugs over the can flange,
and lock them in place by turning cam lock or locking nut. Screw tap assembly into adapter so sealing gasket is fully seated against the can
top. Turn tap inward to pierce the can and close the tap. DO NOT open tap until ready to purge the service hose or dispense refrigerant into
the system.
On 2-piece can taps, be certain tap handle is turned fully inward to the closed position. Check that locking base is turned to its outer limit.
Securely engage locking lugs over the can flange. Turn entire tap assembly (without disturbing the closed setting) downward into the locking
base to pierce the can. DO NOT open tap until ready to dispense into system. CAUT ION: When discharging air conditioning system , use only approved refrigerant recovery/recycling
equipm ent. Make every attem pt to avoid discharging refrigerant into the atm osphere.
NOTE:Recent findings by the EPA indicate that R-11, R-12 and R-113 are harm ful to the Earths' protective
Ozone layer. Make every attem pt possible, to avoid discharging R-11, R-12 or R-113 into the
atm osphere.
CAUT ION: When R-12 is exposed to an open flam e, drawn into a running engine, or detected with a Halide
(propane) leak tester, poisonous phosgene gas is form ed. Keep work areas ventilated and avoid
running engines near work area.
NOTE:Recent findings by the EPA indicate that refrigerant is harm ful to the Earth's protective Ozone layer.
When discharging refrigerant avoid allowing refrigerant to enter the atm osphere. Refrigerant recovery
system should be used when discharging the system .
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SCREW TYPE SEAL CANS
Ensure can tap is fully closed. Screw refrigerant can into can tap fitting until tight. This will pierce the can. Connect tap to center hose on
manifold gauge set. DO NOT open tap until ready to dispense R-12 into system.
CONNECTING LINES & FITTINGS
1. A new "O" ring should be used in all instances when connecting lines and fittings (dip "O" ring in clean refrigeration oil and make
certain it is not twisted during installation). Always use two wrenches to avoid twisting or distorting lines and fittings, tighten coupling
nuts securely.
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT-1056) to open or close. Use the following procedure to
connect or disconnect the spring-coupling fitting.
Ford Spring-Coupling Fitting
1. Discharge system using approved refrigerant recovery/recycling equipment. Place proper end of tool over refrigerant line. Tool fits both
3/8" and 1/2" fittings. Push tool into fitting cage to release spring inside. Pull lines apart and remove tool.
2. Before connecting, check internal spring for damage. If necessary, pry spring out and replace it. Clean fittings and install new "O" rings.

Fig. 1: Assembling Ford Spring
-Coupling Fitting
PLACING SYSTEM IN OPERATION
After component replacement and/or system servicing has been completed and all connections have been made, proceed as follows:
1. Evacuate the system using a vacuum pump.
2. Charge the system with new R-12 (refrigerant) according to each individual vehicle as outlined in the GENERAL SERVICING article.
Also see Refrigerant Capacity in this Section.
3. Leak test the system, with particular attention to all new connections and components.
4. Make a performance test of the system. Never assume that a recharging has automatically corrected a problem.
COMPRESSOR REMOVAL INFORMATION - ISOLATION METHOD
On systems which have compressors equipped with stem-type service valves (Tecumseh), it is possible to isolate the compressor for removal.
Isolating
Turn both high and low pressure manual valves to extreme clockwise (front seat) position. Loosen cap on high pressure manual valve
connection to compressor and allow gas to escape until compressor is relieved of pressure.
COMPRESSOR REMOVAL INFORMATION-DISCHARGE METHOD
This procedure is to be used on vehicles which have compressor equipped with Schrader service valves. In these cases, the compressor cannot
be isolated and the system must be discharged, using approved refrigerant recovery/recycling equipment, prior to compressor removal. WARNING:DO NOT open high side hand valve while air conditioning system is in operation. T his high pressure
could rupture can or fitting at safety can valve, resulting in dam age and personal injury.
CAUT ION: Use ONLY "O" rings designed for these Ford fittings (Motorcraft YF-982). Norm al refrigerant "O" rings
will NOT seal.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00039191
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1991 AIR CONDIT IONING & HEAT
MANUAL A/C
A/C SYSTEM SPECIFICATIONS
SPECIFICATIONS
DESCRIPTION
This A/C-heater system is fully integrated to provide cooling, heating and ventilation with either fresh or recirculated air. A/C system is
expansion valve type. Interior air temperature is controlled by cycling the compressor on and off at different rates. A/C compressor is protected
by a low pressure switch, which stops compressor operation when refrigerant pressure is too low. Compressor operation is cut when throttle is
wide open to improve driveability.
The primary system components are compressor, receiver-drier, evaporator, low pressure switch, thermostatic switch, thermostatic expansion
valve, A/C control module, refrigerant lines and air ducts. See Fig. 1
and Fig. 2 . The heater core is continuously supplied with coolant. To
control temperature, air goes through and/or around heater core by way of temperature blend door.

Fig. 1: Identifying A/C System Components

Courtesy of FORD MOTOR CO. CAUT ION: When discharging air conditioning system , use only approved refrigerant recovery/recycling
equipm ent. Make every attem pt to avoid discharging refrigerant into the atm osphere.
ApplicationSpecification
Compressor TypeNippondenso 10-Cylinder
Refrigerant (R-12) Capacity25 ozs.
System Oil Capacity10 ozs.
Compressor Belt Deflection
New9/32-11/32" (8-9 mm)
Used11/32-7/16" (9-11 mm)
System Operating Pressure (1)
Low Side19-25 psi (1.3-1.7 kg/cm2 )
High Side199-220 psi (13.9-15.4
kg/cm
2 )
(1)When measured at 79°F (26°C).
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