refrigerant type VOLKSWAGEN CORRADO 1990 Repair Manual

* A/C-HEATER SYSTEM UNIFORM INSPECTION GUIDELINES *
Article Text (p. 10)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:27PM
³ ³ components as necessary.

³ ³ Discoloration of oil does not

³ ³ necessarily indicate a system

³ ³ problem.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ REFRIGERANT
REFRIGERANT
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCondition
³ Procedure
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄOvercharge/undercharge
³ Require service to manufacturer's

³ specifications.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCross-contamination
³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´ Require service following
Different types of refrigerants
³ manufacturer's procedures and
in the same system
³ specifications.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´Incompatible refrigerants mixed
³together
³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ AIR DISTRIBUTION
PLENUM/EVAPORATOR CASE/HEATER CASE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCondition
³ Procedure ³ Note
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCracked
³ Suggest repair or ³
³ replacement. ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄAir leaks
³ Require repair or ³
³ replacement ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄRestricted
³ Suggest cleaning, ³
³ repair or replacement.³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄOdor
³ Further inspection ³ Identify source. Suggest

³ required. ³ cleaning or repair.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄNoisy
³ Further inspection ³ Identify source. Suggest

³ required. ³ cleaning or repair.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCold water
³ Further inspection ³ Determine source of leak. Leak
leak in
³ required. ³ may be caused due to restricted
passenger
³ ³ drain tube, cracked evaporator
compartment
³ ³ case, leaking seal or gasket.

³ ³ Require repair or replacement.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

A/C COMPRESSOR OIL CHECKING
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
ARTICLE BEGINNING
1990 AIR CONDITIONING & HEAT
Compressor Oil Checking
ISOLATING COMPRESSOR
NOTE: Only compressors with stem-type service valves can be
isolated.
1) Connect service gauge set to the compressor service valves
and open compressor valves slightly (turn in clockwise). Start engine
and operate air conditioning. Slowly turn compressor suction valve
clockwise toward closed (front-seated) position.
2) When suction pressure is reduced to zero or less, turn off
engine and compressor and quickly turn suction valve stem in to full
front-seated position. Suction pressure should be slightly above zero.
Turn discharge valve into front-seated position.
3) To check oil level, slowly open compressor crankcase plug
to relieve any remaining pressure. After oil level is corrected, cap
service gauge ports on both valves. Back-seat suction service valve to
allow refrigerant to enter compressor. Open discharge valve halfway.
4) Loosen discharge service valve cap, allowing refrigerant
pressure to force air out of compressor. Back-seat service valve and
tighten cap. Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used
in the air conditioning system. This oil is highly refined and
dehydrated to a point where moisture content is less than 10 parts per
million. The oil container must be tightly closed at all times when
not in use, or moisture will be absorbed into the refrigerant oil from
the air.
SERVICING PRECAUTIONS
NOTE: Recent findings by the EPA indicate that refrigerant is
harmful to the earth's protective Ozone layer. When
discharging refrigerant, DO NOT allow refrigerant to enter
the atmosphere. If available, use refrigerant
recovery/recycle systems when discharging system. Always
follow manufacturer's instructions.
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be
isolated and removed without discharging entire system. See ISOLATING
COMPRESSOR at the beginning of this article. Otherwise, discharge
system completely before loosening any fittings.

A/C COMPRESSOR SERVICING
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
ARTICLE BEGINNING
1990 AIR CONDITIONING & HEAT
Compressor Service
* PLEASE READ THIS FIRST *
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
ISOLATING COMPRESSOR
NOTE: Only compressors with stem-type service valves can be
isolated.
1) Connect service gauge set to the compressor service valves
and open compressor valves slightly (turn in clockwise). Start engine
and operate air conditioning. Slowly turn compressor suction valve
clockwise toward closed (front-seated) position.
2) When suction pressure is reduced to zero or less, turn off
engine and compressor and quickly turn suction valve stem in to full
front-seated position. Suction pressure should be slightly above zero.
Turn discharge valve into front-seated position.
3) To check oil level, slowly open compressor crankcase plug
to relieve any remaining pressure. After oil level is corrected, cap
service gauge ports on both valves. Back-seat suction service valve to
allow refrigerant to enter compressor. Open discharge valve halfway.
4) Loosen discharge service valve cap, allowing refrigerant
pressure to force air out of compressor. Back-seat service valve and
tighten cap. Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used
in the air conditioning system. This oil is highly refined and
dehydrated to a point where moisture content is less than 10 parts per
million. The oil container must be tightly closed at all times when
not in use, or moisture will be absorbed into the refrigerant oil from
the air.
DISCHARGING SYSTEM PRECAUTIONS
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
If compressor has stem-type service valves, it can be
isolated and removed without discharging entire system. Otherwise,
discharge system completely using approved refrigerant

A/C SYSTEM PRECAUTIONS
Article Text (p. 2)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
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 125øF (52øC). Never
expose R-12 directly to open flame.
CAUTION: When R-12 is exposed to an open flame, drawn into a running
engine, or detected with a Halide (propane) leak tester,
poisonous phosgene gas is formed. Keep work areas ventilated
and avoid running engines near work area.
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.
NOTE: Recent findings by the EPA indicate that refrigerant is
harmful to the Earth's protective Ozone layer. When
discharging refrigerant avoid allowing refrigerant to enter
the atmosphere. Refrigerant recovery system should be used
when discharging the system.
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

A/C SYSTEM PRECAUTIONS
Article Text (p. 3)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
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.
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.
WARNING: DO NOT open high side hand valve while air conditioning
system is in operation. This high pressure could rupture can
or fitting at safety can valve, resulting in damage and
personal injury.
CONNECTING LINES & FITTINGS
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.
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

A/C-HEATER SYSTEM - MANUAL
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
ARTICLE BEGINNING
1990 MANUAL A/C-HEATER SYSTEMS
Volkswagen
Cabriolet, Corrado, Fox, Golf GL, GTI,
Jetta, Jetta GLi, Vanagon
* PLEASE READ THIS FIRST *
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
AIR BAG WARNING
WARNING: To avoid accidental air bag deployment on Cabriolet, see AIR
BAG DEACTIVATION under SERVICING PRECAUTIONS in this article.
DESCRIPTION
The Volkswagen air conditioning system is a cycling clutch
type. The compressor is cycled on and off by a thermostatic switch to
maintain constant cooling rate.
Other components include an evaporator, expansion valve,
receiver-drier, control panel, condenser, high-pressure switch and a
low-pressure switch. On Vanagon, the A/C thermostat can be found on
left rear pillar, above relay panel assembly (behind trim panel).
The control panel includes a pair of levers and a fan control
switch. The upper lever operates air distribution flap. The lower
lever controls temperature selection. The rotary fan control switch
controls fan speed selection.
OPERATION
SYSTEM CONTROLS
Air Distribution Lever
When in A/C position, cool air is routed to registers and
side air vents. In BI-LEVEL position, cool air is routed to floor
vents as well as registers and side air vents. In HEAT position, warm
air is routed to windshield vents, side window nozzles and floor and
center registers. In DEFOG position, warm air is routed to windshield
vents, side window nozzles and side registers.
Fan Control Knob
The fan control knob controls airflow. As knob is turned
clockwise, air intake opens and fan operates, increasing speed as knob
is moved to extreme right position.

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 8)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
A/C SYSTEM SPECIFICATIONS TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Specification
System Type ............................... Cycling Clutch
Compressor Type ........................ Sanden 5-Cylinder
Compressor Oil Capacity
Cabriolet ...................................... 6.0 oz.
Fox ............................................ 1.4 oz.
Compressor Belt Deflection
All Models .......................... (1) 3/16" (4.8 mm)
System Oil Capacity
Vanagon ........................................ 5.0 oz.
All Others ..................................... 4.6 oz.
Refrigerant (R-12) Capacity
Corrado ...................................... 37-40 oz.
Vanagon ......................................... 50 oz.
All Other Models ............................. 38-40 oz.
System Operating Pressures
Low Side ........................ 26-40 psi (1-2 kg/cm
ý)
High Side ................. 150-210 psi (10.5-19 kg/cm
ý)
(1) - Deflection is measured at center of belt, between
A/C compressor pulley and crankshaft pulley.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ WIRING DIAGRAMS

SCHEDULED SERVICES
Article Text (p. 2)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:49PM
SUPPLEMENTAL RESTRAINT SYSTEM (SRS) AIR BAR WARNING
NOTE: For information on air bag DIAGNOSIS & TESTING or DISPOSAL
PROCEDURES, see AIR BAGS article in the ACCESSORIES/SAFETY
EQUIPMENT Section.
System circuit is grounded by 2 screws beneath the driver's
seat. DO NOT use these screws to ground any other accessory. DO NOT
ground any other components near this system.
AIR CONDITIONING SERVICING (1993 & LATER)
CAUTION: Avoid breathing R-134a refrigerant and PAG lubricant vapors,
exposure may irritate eyes, nose and throat. To remove
R-134a from system use R-134a recycling equipment that meets
SAE J2210 specifications. If accidental system discharge
occurs, ventilate work area before resuming service.
WARNING: R-134a service equipment or vehicle A/C systems SHOULD NOT
be pressure tested or leak tested with compressed air. Some
mixtures of air/R134a have shown to be combustible at
elevated pressures. These mixtures are dangerous and may
cause fire and/or explosions. See AIR CONDITIONING SERVICE
article in GENERAL INFORMATION section.
ANTI-LOCK BRAKE SYSTEM
The anti-lock brake system contains electronic equipment that
can be susceptible to interference caused by improperly installed or
high output radio transmitting equipment. Since this interference
could cause the possible loss of the anti-lock braking capability,
such equipment should be installed by qualified professionals.
On models equipped with anti-lock brake systems, ALWAYS
observe the following cautions:
* DO NOT attempt to bleed hydraulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES Section.
* DO NOT mix tire sizes. As long as tires remain close to the
original diameter, increasing the width is acceptable.
Rolling diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* Use ONLY recommended brake fluids. DO NOT use silicone brake
fluids in an ABS-equipped vehicle.
BATTERY WARNING
WARNING: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is