engine OPEL GT-R 1973 Service Manual

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.

96-54 1973 OPEL SERVICE MANUAL
valve. The filter screen at the inlet port may be re-
placed. Remove screen by threading a lo-32 NF
screw into old filter screen. With a washer and a nut
on the screw arranged to work as a puller screw, hold
the body of the screw and turn the nut. Insert the
new filter screen into the inlet port and lightly tap
screen only enough to seat.
1. Install expansion valve using new o-rings during
installation. Lubricate o-rings prior to installation
using No. 525 viscosity oil.
2. Install evaporator assembly and case attaching
screws. See Figure 9B-70.3. Install blower motor assembly into case and se-
cure with attaching screws. See Figure
9B-69.4. Install finger guard shields and fan housing case.
See Figure
9B-69.5. Install resistor assembly and electrical connector.
Install blower motor connector. See Figure
9B-69.6. Install assembly into car carefully guiding
evaporator pipes up through cowl opening. See Fig-
ure
9B-71.Figure 93-7 1 Inlet and Outlet Pipes and O-Rings
-Opel 1900 Manta
7. Install two (2) upper attaching evaporator at-
taching nuts. See Figures 9B-66 and
9B-67.8. Install two (2) attaching case mounting bracket
to instrument panel screws. See Figure
9B-67.9. Connect two (2) drain hoses underneath evapora-
tor.10. Install evaporator inlet and outlet pipes retainer
and rubber grommet. See Figure
9B-65.11. Connect vacuum cut-off switch and electrical
wiring, making sure the delay restrictor and checkvalve hoses are installed correctly. See Figures
9B-63and 64.
.gB-72 Delay Restrictor and Check Valve Hose.Assembly
12. Install refrigerant hoses and pipes using new
o-rings on line fittings and evacuate system. Refer to
EVACUATING SYSTEM.
13. While system is being evacuated, install in-line
fuse and left side of distributor duct. See Figure 9B-
61.14. Install glove box.
15. Install negative battery cable and charge system.
Refer to CHARGING SYSTEM.
REMOVAL AND INSTALLATION OF CONDENSER
ASSEMBLY -OPEL 1900. MANTA
Removal
1. Remove negative battery cable from battery.
2. Remove air cleaner.
3. Discharge system. Refer to DISCHARGING
SYSTEM.
4. While system is discharging, remove lower radia-
tor hose from radiator and drain coolant into a suita-
ble container.
5. Remove fan shroud.
6. On vehicles with automatic transmission, un-
screw oil lines from connectors on lower radiator
tank and plug lines. It is essential that no dirt enters
the oil lines. When unscrewing oil lines, hold connec-
tors on lower radiator tank with pliers to avoid leak-
ages. Ensure that no dirt enters oil cooler.
7. Remove upper radiator hose from radiator.
8. Remove lower attaching nut and slide radiator
upward and out of engine compartment.
9. Remove inlet and outlet hoses from condenser

REFRIGERANT COMPONENTS ALL MODELS99.55pipes and tape closed the open ends of refrigerant
lines, and also the open ends of the inlet and outlet
pipes of the condenser.
10. Remove two (2) top retaining screws.
Figure
9,S-73 Condenser Retaining Screws - Opel
1900
- Manta
11. Remove radiator grille and two (2) condenser to
body mounting screws. See Figure 98.74.
Figure 98-74 Condenser Assembly and Attachments.
Opel 1900
- Manta
12. Remove condenser.
Installation
If refrigerarit circuit or condenser has been exposed
to the atmosphere and moisture may be present in
the circuit, the system and/or component must beFigure 98-75 Condenser Assembly Mounting Brackets
Opel 1900 Manta
flushed prior to installation. Refer to FLUSHING
THE SYSTEM.
1. Install comjenser into car and install 2 condenser
to body mounting screws. See Figure 98-74. Install
radiator grill.
2. Install 2 top retaining screws.
3. Remove tape from the condenser pipes and re-
frigerant hoses and install hoses using new o-rings on
lines lubricated with No.
525 viscosity oil.
4. Evacuate system. Refer to EVACUATING SYS-
TEM.
5. While system is being evacuated, install radiator
into engine compartment and secure lower attaching
nut.
Figure 98.76 Clearance Between Lower Radiator
Tank and Fan Blades
- Opel 1900 Manta
6. On vehicles with automatic transmissions, fasten

98-56 1973 OPEL SERVICE MANUAL
oil cooler lines to lower radiator tank. It is essential
that no dirt enters the oil lines. When tightening oil
lines hold connectors on lower radiator tank with
pliers to avoid leakages. Ensure that no dirt enters oil
cooler. Torque to 11-15 Ibs. ft.
7. Install fan shroud.
8. Install upper radiator hose.
9. Install lower radiator hose and add collected coo-
lant.
All Opel
1900’s and Manta’s are provided with a
radiator initial fill of an anti-freeze solution contain-
ing corrosion inhibitor. The anti-freeze has either a
glycol or glycerin base and protects the engine
against freezing, down to minus 22 degrees F. (minus
30 degrees C.). Before the start of the cold season,
coolant must be checked with a hydrometer and if
necessary, brought to the necessary specific gravity
by adding anti-freeze. Anti-freeze added, must have
a glycol or glycerin base. As the specific gravities of
all anti-freeze solutions having a glycol or glycerin
base are practically the same, the hydrometer can be
used for all these types. Because of the tolerances of
the hydrometer, or slight differences in specific
gravity, variations of plus or minus 5 degrees can be
expected. Coolant must be checked at a temperature
of plus 68 degrees F. (plus 20 degrees C.).
IO. Install negative battery cable and air cleaner.
11. Charge system. Refer to CHARGING SYS-
TEM.
Figure 99.80 Location of Idler Pulley and Bracket
Assembly
- GTFigure 99.81 Idler Pulley and Bracket Assembly and
Support Bracket GT
REMOVAL AND INSTALLATION OF
COMPRESSOR. GT
I. Removenegative battery cable from battery.
Figure 98-82 Compressor Adapter Fitting, Ground
Wire. and Front and Rear Mounting Bolts
- GT
Figure 99.83
Elecirical Connector and Ground Wire
GT

r98-82 1973 OPEL SERVICE MANUAL
SPECIFICATIONS
Tightening Specifications
Part
Location
NutDrivePlateNut toCompressorShaft..............................
NutRear Head to Shell................................................................
CaPSchraderServiceValve......................................................
Compressor Specifications
Torque
Lb. Ft.
15
21
5Type
..............................................................................................Six Cylinder Axial Opposed
Make
............................................................................................................................Frigidaire
Effective Displacement (Cu. In.)
..........................................................................................
9.2Oil
..........................................................................................................................525 Viscosity
Oil Content (New)
....................................................................................................10 Fl. Oz.
Air Gap Between Clutch Drive Plate and Pulley
......................................0.022 to 0.057 In.
Clutch Type
................................................................................................................h4agnetic
Belt Tension
..............................................................................................1 lo-125 Lbs. Irritial
....................................................................................................................80 Lbs. Retension
Pipe and Hose Connection Torque Chart
Metal TubeThread andSteel TubingAluminum orNominal Torque
I
Outside Dia.Fitting SizeTorqueCopper TubingWrench Span
Lb. Ft.Torque
Lb. tit.
5-7
General SpecificationsThermostat Opening Temperature
.._.....,,,...__....,,.............................................................. 189
Capacity of Cooling System With Air Conditioner (Quarls)
.,,..___....___............... 6 (Approx.)Type of Refrigerant
.___,,,._...,.,,,.__.....,,,.......,,,,.......,,,...................,,,......,,,............ Refrigerant 12
Refrigerant Capacity (Fully Charged)
Opel
1900-Manta,,._....,,,,._...._.,,,,.......,,,........,,............................................................2 Lbs.
GT
,..__..,..,..__..,,,.......,,,,.......,,,........,,,.,......,,,,,......,,.,,........,,.......,,..........,,............... 2 l/4 Lbs.
Functional Test Procedures1. Place transmission in park for automatics and in
neutral for manuals. Apply hand brake.
2. Turn blower switch to HI position,
3. Turn temperature switch to MAX position-.
4. Run engine at 2000 RPM for ten (10) minutes with
car doors and windows closed and the hood up. Place
a commercial high volumn fan in front of condenser
if head pressure should exceed 250 psig.A commercial high volumn fan should be placed in
front of the condenser at high ambients to bring the
pressures to within the limits specified in the Func-
tional Charts. When testing the Opel 1900 and
Man& a thermometer should be placed in a position
to read the temperature of the air discharging from
the right-hand A/C outlet. When testing the GT, a
thermometer should be placed in a position to read
the temperature of the air discharging, from the left-
rear
,A /c outlet.

REFRIGERANT COMPONENTS ALL MODELS9B- 83
FUNCTIONAL TEST - OPEL 1900.
MANTA
Temp. of Air Entering
Cond.
Engine RPM
Camp. Head Pressure*
Suction Press.’
Discharge Air Temperature*
*When compressor clutch disengages,
FUNCTIIONAL TEST - GT
Temp. of Air Entering Cond.
Engine RPM
Camp. Head Pressure”
Suction Press.”
Discharge~Air Temperature*
“When compressor clutch disengages70
8090100110
20002000200020002000
155.165195.205200-210
250.260270.280
1922222729
38-4340.4542-47
45-5047-52
708090100110
2000
2000200020002000
125.135145.155180-190
210-220150.260
1720202224
37-42
38.4339-4440-4545-50

RADIO. GT9c- 105
RADIO
GTCONTENTS
Subject
DESCRIPTION AND OPERATION: (Not Applicable)
DIAGNOSIS:
RadioTroubleDiagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE AND ADJUSTMENTS:
Antenna Trimmer Adjustment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
RemovingandInstallingRadio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS: (Not Applicable)
Page No.
9c-105
9C-106
9c-107
DIAGNOSIS
RADIO TROUBLE DIAGNOSISBecause radio problems are most often repaired at
United Delco authorized warranty repair stations,
the tendency for many dealer servicemen is to
remove the set when a problem is reported, without
any preliminary diagnosis. This results in a large
number of radios showing up as “NO TROUBLE
FOUND” units when received by the warranty re-
pair stations. This indicates that the trouble can
often be corrected without removal of the radio.
The inconvenience to an owner of driving without a
radio while his set is being serviced at a warranty
station can frequently be avoided if the following
quick checks are used to eliminate external radio
system :problems before removing the radio for re-
pair.
Always determine from the owner the exact nature
of the radio problem as an aid to diagnosis. Knowing
whether the condition is intermittent or constant,
whether it occurs with engine off or running, with
car stationary or moving, will help to pinpoint the
problem. Never turn on radio with speaker discon-
nected.
Radio Ii
Inoperative.1. Turn on the radio. The dial should light and a
thump should be heard from the speaker.a. If a thump is heard, go to Step No. 2 for antenna
check.b. If no thump is heard,
check the fuse.
(1) If fuse is bad, replace and try radio again. Race
engine and, if fuse blows again,‘remove the radio and
speaker assembly for repair by
4 trained radio techni-
cian.
(2) If fuse is good, check to
s&e that the speaker-to-
receiver interconnecting cable is connected securely.
If there is still no thump when the radio is turned on,
remove the receiver and speaker for repair.
2. Check the antenna by substituting with one held
out the car window.
a. If radio is still dead with substitute antenna,
remove the receiver and spea!er for repair.
b. If radio operates near normal with substitute an-
tenna, some part of the car antenna or lead-in is at
fault.
Radio Reception Is Weak1. Check to see if antenna trimmer is peaked.
a. Position antenna at a height of 31 inches.
b. Tune radio to weak station at or near 1400 KHz
on the dial, and turn volume control to maximum.

9C-106 1973 OPEL SERVICE MANUAL
c. Adjust trimmer screw for maximum volume.
d. If antenna trimmer does not have a definite peak, check for defective antenna by substitution.
2. Check that the speaker connection is plugged in
SXUdY.
3. If the radio is still weak, remove the receiver and
speaker assembly for repair.
Radio Is Noisy
1. Radio is noisy all the time:
a. Check for defective antenna by striking antenna
with hand. If static is heard while tapping, replace
antenna.
b. If antenna is not defective, remove receiver and
speaker for repair.
2. Radio is noisy only when jarred:
a. Check antenna as in Step No. 1 above.
b. Check speaker connection. If speaker connection is not at fault, remove receiver and speaker for re-
pair.
3. Radio is noisy when engine is running:
a. Check noise suppressor by substituting on genera-
tor with known good one.
b. Check to see that antenna is mounted securely,
grounding the antenna base to the fender. The an-
tenna lead-in wire is shielded and the shield should
have good ground connection at the receiver and the
antenna base.
c. Check for other car wiring, passing too close to
radio receiver case.
d. If engine noise is still present, remove receiver and
speaker for repair.
4. Radio is noisy when car equipment is operated,
such as directional lights or brake lights:
Check for defective antenna lead-in wire or, loose
antenna mounting, as in Step No. 3b above.
MAINTENANCE AND ADJUSTMENTS
ANTENNA TRIMMER ADJUSTMENT
An antenna trimmer adjusment screw is provided for
matching of the antenna coil in the receiver to the car antenna. This adjustment must always be made after
installation of a receiver or an antenna, or after re-
pair to these units. This adjustment should also be
performed whenever radio reception is unsatisfac-
tory.
1. Position antenna to a height of 31 inches.
2. Tune receiver
tb a weak station at or near 1400
KHz that can barely be heard
with volume turned
fully up.
3. Insert a small-bladed screwdriver in antenna trim-
Figure 9C-1 Location of Access Trim Plug
Figure
9C-2 Removing Hex Head Screw