Mazda RX7. Manual — part 16

A/C SYSTEM GENERAL DIAGNOSTIC PROCEDURES

Article Text (p. 5)

1983 Mazda RX7

For www.iluvmyrx7.com

Copyright © 1998 Mitchell Repair Information Company, LLC

Sunday, August 26, 2001 04:42PM

and on too rapidly. Switch
NORMAL NORMAL Cycling clutch systems only - Misadjusted
to compressor doesn't turn on Thermostatic
HIGH soon enough. Discharge air Switch or
becomes warm as low side Defective
pressure rises. Pressure
Sensing Switch
LOW LOW Bubbles in sight glass. Low R-12
Outlet air slightly cool. Charge
LOW LOW Sight glass clear. Outlet Excessively
air very warm. Low R-12
Charge
LOW LOW Outlet air slightly cool. Expansion
Sweating or frost at Valve Stuck
expansion valve. Closed Screen
Plugged or
Sensing Bulb
Malfunction
LOW LOW Outlet air slightly cool. Restriction
High side line cool to touch. on High Side
Sweating or frost on high
side.
LOW HIGH Evaporator outlet pipe cold. STV Stuck
Low side goes into vacuum Open
when blower is disconnected.
HIGH LOW Evaporator outlet pipe warm. STV Stuck
Outlet air warm. Closed
HIGH LOW Noise from compressor. Compressor
Malfunction
HIGH HIGH Outlet air warm. Liquid Compressor
line very hot. Bubbles in Malfunction
sight glass. or R-12
Overcharge
HIGH HIGH Outlet air slightly cool. Large Amount
Bubbles in sight glass. of Air and
Moisture in
System
HIGH HIGH Outlet air warm. Evaporator Expansion
outlet sweating and frost. Valve
Stuck Open

(1) - If equipped with a low refrigerant charge protection system,
compressor operation may have stopped.

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

END OF ARTICLE

A/C SYSTEM PRECAUTIONS

Article Text

1983 Mazda RX7

For www.iluvmyrx7.com

Copyright © 1998 Mitchell Repair Information Company, LLC

Sunday, August 26, 2001 04:42PM

ARTICLE BEGINNING

AIR CONDITIONING & HEAT
A/C System Precautions

* 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.

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

NOTE: Recent findings by the EPA indicate that R-11, R-12 and R-113
are harmful to the Earths' protective Ozone layer. Make every
attempt possible, to avoid discharging R-11, R-12 or R-113
into the atmosphere.

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) 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

A/C SYSTEM PRECAUTIONS

Article Text (p. 2)

1983 Mazda RX7

For www.iluvmyrx7.com

Copyright © 1998 Mitchell Repair Information Company, LLC

Sunday, August 26, 2001 04:42PM

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

ø

F (52

ø

C). 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)

1983 Mazda RX7

For www.iluvmyrx7.com

Copyright © 1998 Mitchell Repair Information Company, LLC

Sunday, August 26, 2001 04:42PM

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 COOLING SYSTEM 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