1973 OPEL GT-R service

98.40 1973 OPEL SERVICE MANUAL
2. Interconnect manifold and gage set (J-5725-01),
gage charging lines (J-5418) and gage adapters
(J-5420) to air conditioning system as shown in Figure
9B-40.3. Place transmission in “Park” for automatics and
in neutral for manuals. Apply hand brake.
4. Turn blower switch to the “Hi” position.
5. Turn temperature switch to “Max” position.
6. Run engine at 2000 RPM for ten (10) minutes with
car doors and windows closed and the hood up. Place
a high volume industrial type fan in front of radiator
if head pressure should exceed 250 psi and also at
high ambients to bring the pressures to within the
limits specified in the Functional Charts in Division
V.In the case of the Opel 1900 and the Manta, a ther-
mometer should be placed in a position to read the
temperature of the air discharging from the right-
hand A/C outlet. In case of the GT, a thermometer
should be placed in a position to read the tempera-
ture of the air discharging from the left-rear A/C
outlet.
HEATER-AIR CONDITIONER REFRIGERANT
CIRCUIT TROUBLE DIAGNOSIS GUIDE
Insufficient Cooling (Check Air Flow)
Normal Air Flow (Inspect system for visual defects.
Run functional tests.)
Discharge Air
- Normal Temp Check for air leaks
through dash, car body, windows, or from heater or
ventilators.
Discharge Air
- High Temp Check sight glass for
foaming and compressor clutch for engagement.
No Compressor Clutch Engagement Check connec-
tions at clutch switch, harness connectors, and check
clutch switch.
No Foaming Compare evaporator pressure to that
on functional test table.
Foaming System is probably low on refrigerant.
Check for leaks, repair, evacuate, and charge. If
foaming still occurs, check for restriction in refriger-
ant lines between condenser and receiver dehydrator.
Evaporator Pressure Normal Compare head pres-
sure to pressure on functional test table.
Evaporator Pressure Low Ice may be forming on
evaporator. Low volume of air discharging at A/C
outlet after system has been running above idle con-dition
,for approximately 15-30 min.utes. Discharging
air gradually elevating in temperature. Check expan-
sion valve. If valve isn’t permitting flow of liquid,
this will be indicated by a warm pipe out of the
evaporator. This may be caused by: 1) Clogged or
Plugged inlet screen in the expansion valve; 2)
Broken capillary line; or 3) Discharged temperature
bulb. If the valve is okay, the pipe out of the evapora-
tor will be cold.
Evaporator Pressure High Check the expansion
valve to determine if themobulb is making good con-
tact and is properly insulated. Operate engine at 2000
RPM with maximum air conditioning setting. If
evaporator pressure remains high, feel suction line.
If line feels frosty or extremely
(cold with relative
high ambient conditions, then partially cover the
condenser to obtain head pressures from 265 psi to
280 psi maximum. If evaporator pressure rises above
30 psi, change the expansion valve.
Also, check if compressor may be the cause due to
some internal or external mechanical trouble which
prevents reduction of pressure. Check for external
troubles, slipping belt, bad clutch and/or pulley, or
improper clutch engagement, before investigating
the compressor internally.
Head Pressure High Check for the following: Con-
denser air flow low, air in system, excessive refriger-
ant in system, restriction in condenser.Head.PressureLowRestriction in flow of refrigerant
to evaporator, or expansion valve plugged or defec-
tive.
Low Air Flow (Check blower operation and
evaporator. Check operation of controls.)
Ice BIocking Evaporator Run functional test. If
evaporator pressure is low, ice may form on evapora-
tor and reduce air flow.
Evaporator Pressure Low Ice may be forming on
evaporator. Low volume of air discharging at A/C
outlet after system has been running above idle con-
dition for approximately 15-30 minutes. Discharging
air gradually elevating in temperature. Check expan-
sion valve. If valve isn’t permitting flow of liquid,
this will be indicated by a warm pipe out of the
evaporator. This may be caused by: 1) Clogged or
plugged inlet screen in the expansion valve; 2)
Broken capillary line, or 3) Discharged temperature
bulb. If the valve is okay, the pipe out of the evapora-
tor will be cold.BlowerNot OperatingCheck for the following: Fuse
blown, blower switch defective, wire broken or loose
connection, poor ground connection, or blower mo-
tor defective.

REFRIGERANT COMPONENTS ALL MODELS9s. 41
BIower Operating Normal Check for the following:Restriction or leakage in air ducts, A/C outlets not
opening.2. Do not carry cylinder in passenger compartment
of car.3. Do not subject cylinder to high temperatures.
MAINTENANCE AND ADJUSTMENTS4. Do not weld or steam clean on or near cylinder.
5. Do not fill cylinder completely.
GENERAL SERVICE INFORMATION AND SAFETY
PRECAUTIONS6. Do not discharge vapor into area where flame is
exposed or directly into engine air intake.
General InformationAll subassemblies are shipped sealed and dehy-
drated. They are to remain sealed until just prior to
making connections, and should be at room tempera-
ture before uncapping. This prevents condensation of
moisture from air that enters the system.
All precautions should be taken to prevent damage
to fittings or connections. Even minute damage to a
connection could cause it to leak. Any fittings with
grease or dirt on them should be wiped clean with a
cloth dipped in alcohol.
Do not clean fitting or hoses with solvents because
they are contaminants. If dirt, grease or moisture
gets inside the pipes or hoses and cannot be removed,the pipe or hose is to be replaced. Use a small amount
of clean refrigeration oil on all tube and hose con-
necting joints, and lubricate the
“0” ring gasket with
this oil before assembling the joint. The oil will help
in effectitig a leak-proofjoint and assist the
“0” ring
to slip into the proper location without being cut or
damaged. Always use new
“0” rings.
When tightening joints, use a second wrench to hold
the stationary part of the connection to prevent
twisting and to prevent hose kinking. Kinked hoses
are apt to transmit noise and vibration. Tighten all
connections in accordance with recommended
torques (see Division VI, Specifications).7. Do not expose eyes to liquid
- WEAR SAFETY
GOGGLES whenever discharging, charging or leak
testing system.
CHARGING AND DISCHARGING SYSTEMRemoval of any part in the refrigerant circuit will
require discharging of the entire system.
Discharging the System1. Remove caps from gauge fittings on the compres-
sor adapter fitting on the compressor.
2. With both valves on manifold gauge set (J-5725-
04) closed (clockwise), attach manifold to the com-
pressor adapter fitting on the compressor, using
J-5420 valve adapter at suction gauge fitting and
J-9459 valve adapter at discharge gauge fitting. See
Figure
9B-41.3. Fully open high pressure valve on manifold gauge
set to allow escape of refrigerant from system
through the manifold gauge set and out the center
fitting and hose. (Place end of hose in clean container
to collect oil loss due to rapid discharge of system).
4. When hissing ceases, indicating all refrigerant
has escaped, close high pressure valve on manifold
gauge set by turning valve clockwise.
Do not connect receiver-dehydrator assembly until
all other connections have been made. This is neces-
sary to itisure maximum moisture removal from sys-
tem.It is important that air conditioning hoses do not rest
on or contact body sheet metal except where neces-
sary. Because of the high frequency at which the
compressor operates, the passenger compartment is
susceptible to transfer of noise.
Evacuating the SystemWhen the refrigeration system is depressurized and
opened for service, some air will enter the lines, re-
gardless of how quickly openings are capped. In
or-der to remove this air and as much as possible of the
moisture it contains, the complete system must be
evacuated. Evacuating is merely the process of
removing all air from the system, thereby creating a
vacuum in the system.
Safety PiecautionsThe following safety precautions should always be
followed~,when servicing refrigerant charged compo-nents:Under no circumstances should alcohol be used in
the system in an attempt to remove moisture,
regard-less of the successful use of alcohol in other refrigera-
tion systems.
Preparations for Evacuating Complete System
1. Do not leave Refrigerant-12 cylinder uncapped.
1. Check the low pressure gauge for proper calibra-

98-42 1973 OPEL SERVICE MANUAL
SCHRADER VALVE
ADAPTER J-54201COMPRESSOR(TOP VIEW)[/--DISCHARGE LINE
ILOW PRESSURE\ GAUGE
MANIFOLD AND
-GAUGE SET
J-5725-01
rGAUGE LINES
(5) J-541899-31
Figure 98.41 Set-Up For Discharging System
tion. With the gauge disconnected from the refrigera-
tion system, be sure that the pointer indicates to the
center of zero. Lightly tap gauge a few times to be
sure pointer is not sticking. If necessary, calibrate as
follows:
A. Remove cover from gauge.
B. Holding gauge pointer adjusting screw firmly with
one hand, carefully force pointer in the proper direc-
tion in proper amount to position pointer through
the center of
“0” position. Tap gauge a few times to
be sure pointer is not sticking. Replace gauge cover.
2. If gauge is not already connected to compressor,
connect as follows:
A. Close hand shut-off valves on gauge set by turning
clockwise.B. Remove caps from gauge fittings on the compres-
sor adapter fitting.
C. Attach valve adapter (J-5420) to end of the hosefrom the low pressure gauge and connect thisadapl:er fitted hose to suction gauge fitting.
D. Attach valve adapter (J-9459) to end of hose from
the high pressure gauge and connect this adapter
fitted hose to the discharge fitting.
3. Attach a flexible gauge hose to center fitting of
the gauge set and attach the other end of this hose
to vacuum pump (J-5428-03).
Evacuating Complete System
1. Turn hand shut-off valve on low pressure gauge
of gauge set to full clockwise position.
2. Slowly turn valve on high pressure gauge coun-
terclockwise from full clockwise position, letting any
pressure build-up escape completely. Close high
pressure valve.
3. Check oil level in vacuum pump and, if neces-
sary, add refrigeration oil. Make sure dust cap on
discharge side of pump has been removed.

9B-44 1973 OPEL SERVICE MANUAL
Do not turn refrigerant drum upside down, as this
would allow liquid refrigerant to enter compressor
which may cause damage.
4. If line at center gauge fitting has not been purged
of air, loosen line at center fitting on gauge set and
crack valve on refrigerant drum to blow air from
line. Retighten line at center fitting and record exact
weight of refrigerant tank in water on the scales.
5. Open valve on refrigerant drum and both valves
on gauge set to allow refrigerant to flow into system.
Continue charging until the scales show that 2
Ibs.Opel 1900
- Manta and 2 l/4 lbs. GT, of refrigerant
have been transferred from refrigerant drum to sys-
tem.If full charge cannot be obtained, close both valves
on gauge set, start engine, and set temperature con-
trol knob to full cold position with blower in Max Hi.
Open low pressure valve on gauge set slowly and
leave open until full charge is added.
WARNING: Observe high pressure gauge while charg-
ing with compressor running. Shut
offengine ifpres-
sure exceeds 250 psi. A large fan placed in front
ol
the car wi// help reduce excessively high head pres-6. Close both valves on gauge set (high pressure valve
will already be closed if charging was completed by
running compressor) and close valve on refrigerant
drum.
If the engine was used to complete the charge into
the system, close valve on refrigerant drum to permit
compressor to draw any refrigerant left in the line
from the drum to the center fitting of the gauge set,
then close the low pressure valve on the gauge set.
7. Operate engine at 2000 RPM with temperature
control knob at full cold, blower speed in Max Hi.
After ten minutes of operation, observe appearance
of refrigerant in receiver-dehydrator. If bubbles are
observed, open low pressure gauge valve and valve
on refrigerant drum to allow more refrigerant to en-
ter system. Close valve when receiver-dehydrator
clears
up.If an air inlet temperature is below 70 degrees F.
when this check is made, bubbles may appear, even
though the proper amount of refrigerant is in the
system. Air inlet temperature must be 70 degrees F.
or above to make an accurate check.
8. When refrigerant has been installed, continue to
operate system and test for proper operation as ou-
tlined under “Operational Test”.
9. When satisfied that air conditioning system is op-
erating properly, stop engine, remove gauge set and
replace protective caps on compressor fittings.10. Using leak detector, check complete system for
leaks.Disposable Can Method
After having
depress&ed, repaired (if necessary)
and evacuated the refrigerant system, the system
may be charged as follows using refrigerant in dis-
posable cans:
1. Obtain three (3) 1
lb. cans or one 12 lb. can of
refrigerant.
2. If using 1 lb. cans, mount two (2) cans in J-6272-
02 (Multi-opener) or attach J-6271 (single-can
opener valve) on one can. If using the 12
lb. disposa-
ble can, attach J-23390 (disposable can control valve)
on can.WARNING: Make sure outlet valve on opener is
closed (clockwise) before installing opener.A. If the J-6272-02 multi-opener is used, raise lock-
ing lever, position three (3) cans of refrigerant and
force locking lever down to secure cans and at same
time puncture top of can to make it ready for charg-
ing.
B. If the J-6271 valve is used, back off the valve from
the can top retainer, slip the valve onto the can and
turn the valve into retainer until tight. DO NOT
open outlet valve during this operation, as turning
the valve into the retainer punctures top of can to
make it ready for charging.
3. Connect center flexible line of gauge set to fitting
on a can opener valve. If the line at center gauge
fitting has not been purged of air, loosen line at
center fitting on gauge set and “crack” valve at can
opener (for a second or two) to force air from the
line. Retighten line at center fitting.
4. Open valve at refrigerant source and at low and
high pressure valves on manifold gauge set. Leave
valve open at refrigerant source until all refrigerant
(when using 1 lb. can) has ‘entered the refrigeration
system or system is fully charged. Close valve on can.
A. If the system is charged using
1 lb. cans and the
J- 627 1 valve, disconnect valve from can. Leave valve
closed to flexible line to the center fitting of the
manifold gauge set. Install valve on a new and full
disposable can of refrigerant.

98-46 1973 OPEL SERVICE MANUAL
shut off vacuum pump. Open refrigerant control
valve and allow some refrigerant to enter system.
Locate and repair all leaks.
7. After evacuating for 15 minutes, add l/2 lb. of
refrigerant to system. Purge this
l/2 lb. and reevacu-
ate for 15 minutes. This second evacuation is to be
certain that as much contamination is removed from
the system as possible.
8. Only after evacuating as above, system is ready
for charging. Note reading on sight glass of charging
cylinder. If it does not contain a sufficient amount
for a full charge, till to proper level.
9. Close low pressure valve on charging station.
Fully open station refrigerant control valve and al-
low all liquid refrigerant to enter system. When full
charge of refrigerant has entered system, turn off
refrigerant control valve and close both hand shut-
off valves.
10. If full charge of refrigerant will not enter system,
close high pressure control and refrigerant control
valves. Start engine and run at low idle with com-
pressor operating. Crack refrigerant control valve
and low pressure control on station. Watch low side
gauge and keep gauge below 50 psi by regulating
refrigerant control valve. Closing valve will lower
pressure. This is to prevent liquid refrigerant from
reaching the compressor while the compressor is op-
erating. When required charge has entered system,
close refrigerant control valve and close low pressure
control.
11. System is now charged and should be perform-
ance- tested before removing gauges.
Adding Refrigerant
The following procedure should be used in adding
small amounts of refrigerant that may have been lost
by leaks or while opening system for servicing the
compressor. Before adding refrigerent to replace that
lost by leaks, check for evidence of oil loss and add
oil if necessary.
This procedure will only apply if the air inlet temper-
ature is above 70 degrees F. at the condenser.
1. Remove caps from compressor gauge fittings.
Attach gauge set to gauge fittings, making sure
adapter (J- 5420) is between low pressure gauge hose
and suction gauge fitting, and J-9459 is between high
pressure gauge hose and discharge gauge fitting.
2. Start engine, turn air conditioning temperature
control knob to full cold position, blower switch to
Max Hi. Operate for ten
(IO) minutes at 2000 RPM
to stabilize system.
3. Observe the refrigerant through the sight glasscover of receiver-dehydrator with the system operat-
ing,
IO see if there are any bubbles evident.
a. If no bubbles are evident, then bleed system slowly
through the discharge valve until bubbles appear in
the receiver-dehydrator. Add 1 lb. of refrigerant as
explained under “Charging the
ISystem”.b. If bubbles are visible in the receiver-dehydrator
with the temperature control krlob in the full cold
position and the blower at MAX speed, it indicates
a partial or complete plug in a line, a shortage of
refrigerant, or both. Correct condition. Add refriger-
ant
u~ntil the sight glass clears, then add another 1 lb.
of refrigerant.
4. Attach flexible hose from center fitting of gauge
set loosely to refrigerant drum or on disposable can
valvxs. Open high and low pressure valves on the
gauge set slightly to purge pressure gauge lines of air.
Tighten fitting of refrigerant drum or can when satis-
fied ihat all air has been removed from gauge lines.
Close (clockwise) both hand shut-off valves or gauge
set.5. Partially charge system.
REFRIGERANT DRUM METHOD:
A. Place pail containing hot water that does not have
a temperature exceeding 125 degrees F. on scales,
place refrigerant drum in pa” containing water, note
weig,ht and only open low pressure valve on gauge
set.B. Start engine, turn temperature control knob to full
cold position and place blower switch in Max Hi.
Operate engine for 10 minutes at 2000 RPM to sta-
bilize system.
C. With compressor operating, slowly open valve on
refrigerant drum and allow refrigerant to flow into
system (through manifold gauge set) until liquid in-
dicator clears up and immediately shut off valve ai
gauge set or on refrigerant drum. Check weight of
refrigerant drum and pail of water. Then slowly open
valve on gauge set (or refrigerant drum) and add one
more lb. of refrigerant. Note total amount of refriger-
ant added.
DISPOSABLE CAN METHOD:
A. Make sure the outlet valve on the J-6271 valve is
fully clockwise and attach the J-6271 to a 1 lb. can
of refrigerant by backing off the valve from the top
of the retainer, slipping the valve onto the can and
turning the valve into the retainer until tight. DO
NOT accidentally open outlet valve during this oper-
ation, as turning the valve into the retainer punctures
the top of the can to make it ready for charging.
.

REFRIGERANT COMPONENTS ALL MODELS9a- 47
B. Connect center flexible line of gauge set to the
fitting on the valve.
C. Start engine, turn temperature control knob to full
cold position, set blower switch to Max Hi. Operate
engine for 10 minutes at 2000 RPM to stabilize sys-tem.D. With compressor operating, slowly open valve on
refrigerant can and allow refrigerant to flow into
system (through manifold gauge set) until liquid in-
dicator clears up and immediately shut off valve at
gauge set and on refrigerant can. Check weight of
can and valve assembly and record.
E. Add an additional 1 lb. of refrigerant by adding
refrigerant from the can just weighed until can is
empty. Attach another can and add refrigerant until
can and valve assembly weigh the same as recorded.
6. Close valves at refrigerant drum or
can,7. Test for leaks and make operational check of
system.
ADDING OIL TO THE SYSTEM (MAJOR
OVERHAUL)The oil in the refrigeration system does not remain
in the compressor during system operation, but cir-culates throughout the system. The compressor is
initially charged with 10 oz. of 525 viscosity oil.
After system has been in operation the oil content in
the compressor will vary depending on the engine
RPM and air conditioning load. At higher engine
RPM’s a lesser amount of oil will be retained in the
compressor reservoir. It is important that the total
system oil content does not vary from a total of10-l/2 oz. Excessive oil content will reduce cooling
capacity. Inadequate oil content may result in dam-
age to compressor moving parts.
The refrigeration system will not require adding of
oil unless there is an oil loss because of a ruptured
line, badly leaking compressor seal, replacement of
evaporator, compressor, receiver-dehydrator, or loss
due to a collision. Oil is generally added to the sys-
tem via the oil drain hole in the lower side of the
compressor for this condition. To add oil to the sys-
tem via the compressor, the compressor must be
removed. If no major loss of oil has occurred and a
component (condenser,receiver-dehydrator or
evaporator) is removed for servicing, the oil may be
added directly to the component. To add oil to a
component removed for servicing and when no ma-
jor loss has occurred, drain and measure oil in com-
ponent, then replace with a like amount. To add oil
to the system when a major loss of oil is evidenced,
or when the compressor is being serviced, remove
compressor, drain and measure oil, and replace oil
amount specified in the Oil Replacement Table.
OIL REP,‘LACEMENT TABLE
Condition
1. Major loss of oil and
a component (conden-
ser, receiver-dehydra-
tor, or evaporator)
has to be replaced.
Amount of Oil Drained
From Compressora. More than 4 oz.Amount of 525 Oil to Install
In Compressora. Amount drained from compressor,
plus amount for component
being replaced.
Evaporator
- Add 2 oz.
Condenser
- Add I oz.
Receiver-Dehydrator
- Add 1 oz.
b. Less than 4 oz.b. Install 6 oz., plus amount for
component being replaced as
shown above.
2. Compressor being
replaced with a
ser-vice replacement
compressor
- no major
oil loss.a. More than 1
l/2 oz.a. Same amount as drained from
compressor being replaced.
b. Less than 1
l/2 oz.b. Install 6 oz

98-48 1973 OPEL SERVICE MANUALCondition3. Compressor being
replaced with a ser-vice replacement
compressor major
oil loss evident.
Amount of Oil Drained
From Compressora. More than 4 oz.Amount of 525 Oil to Install
In Compressor
a.
Same amount as drained from
compressor being replaced.4. Compressor being
rebuilt or repaired
-no major oil loss
evident.b. Less than 4 oz.
a. More than 1
l/2 oz.b. Install 6 oz.
a. Same amount a.s drained from
compressor, plus
1 oz. additional.
5. Compressor being
rebuilt or repaired
major loss of oil
evident.b. Less than 1
l/2 oz.
a. More than 4 oz.b. Install 7 oz.
a. Same amount as drained from
compressor, plus 1
ozadditional.If foreign material is noted in oil drained from sys-
tem or evidence of moisture is obvious in the compo-
nents removed, it is recommended that the entire
system be flushed and the receiver-dehydrator be
replaced. A full oil charge of 10 oz. of 525 viscosity
refrigeration oil should be replaced in the system. It
should be noted that all service replacement com-
pressors will be supplied with 10 pz. of oil. In most
cases it will be necessary to drain oil from service
replacement compressor and refill it with amount as
specified in the Oil Replacement Table.filter screen on the expansion valve should be re-
placed. If the evaporator assembly is flushed while
installed in the car, the temperature bulb on the
evaporator outlet pipe must be disconnected to keep
the expansion valve from closing at the inlet source.
FLUSHING THE SYSTEMIt is recommended that dry nitrogen be used as a
flushing agent due to the low cost involved. In addi-
tion, dry nitrogen will not cause a temperature drop,
as in the case of refrigerant-12, which results in
thickening of refrigerant oil. Dry nitrogen has the
additional advantage of removing moisture from thesystem.Flushing of the system may involve all the compo-
nents of the system or individual components in the
system. The components may be flushed while
mounted in the engine compartment or may be
removed for flushing. When a component is not
removed, disconnect all refrigerant lines or hoses
attached to component. To perform flushing operat-
ion, connect a cylinder of refrigerant-12 to the com-
ponent to be flushed, ,then invert the cylinder and
open the cylinder valve so that the liquid refrigerant
pours out and through the component. When liquid
Refrigerant-12 reaches atmospheric pressure, it im-
mediately drops to minus 21.7 degrees F. Insure that
area immediately surrounding outlet of component is
clear of anything that may be damaged by contact
because of the sudden drop in temperature.MAJOR REPAIR
REMOVAL AND INSTALLATION OF
COMPRESSOR
- OPEL 1900 - MANTA
Removal
I. Remove negative battery cable from battery.
2. Remove air cleaner and heat pipe. Cover the
carburetor to keep out dirt etc.
3. Discharge system. Refer to DISCHARGING
SYSTEM.
In all cases where a complete system flushing operat-4. While system is discharging remove sheet metal
ion is performed, the receiver-dehydrator and thecover. See Figure
9B-50.

96-50 1973 OPEL SERVICE MANUALIFigure 98.53 Compressor Installation Opel 1900 Manta
I2. Disconnect refrigerant lines to both ends of re-
ceiver-dehydrator and tape closed open ends of re-
frigerant lines, and also the open ends ofthe inlet andoutlel pipes of the receiver-dehydrator.
IFigure 98.54 Compressor Pulley. Idler
Pulley andFigure 98.55 Hose and Clamp Installation - Opel
Mounting Bracket Assembly
- Opel 1900 Manta1900 Manta