1973 OPEL GT-R check engine

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.

REFRIGERANT COMPONENTS ALL MODELS9t3- 45
B. If system is charged using J-6272-02, close the
valve of opener after all cans are empty. Release the locking lever and discard the three (3) empty cans.
If this tool will be used to complete the charge with
additional cans to provide the required refrigerant
charge, leave the empty cans in position, locate one
full can and lock the lever into place. These empty
cans balance the assembly and prevent the loss of
refrigerant through the open “series” passage. Align
the pierced hole in the empty can with the punch in
the cover of the tool.
If the J-6271 valve for single cans is available, com-
plete charging as explained in 4a above.
5. Close high side valve on manifold gauge set,
WARNING: Prior to starting up engine, the high side
valve on the charging manifold must be closed due
to excessive pressure
bui/d-up which can result in
bursting of the container(s) causing serious injury. If
you are inexperienced in the use of this procedure, seek professional assistance.
6. Operate engine at 2000 RPM with temperature
control knob at full cold position and blower speed
on Max Hi. If air inlet temperature at the condenser
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.
7. When refrigerant has been installed, continue to
operate system and test for proper operation as ou-
tlined
under “Operational Test”.
8. When satisfied that the air conditioning system
is operating properly, stop engine, remove gauge set
and replace protective caps on suction and discharge
fittings.
from thegauge fitting to prevent damage-or injury to
personnel.
9. Using a leak detector, check complete system for
leaks.
Charging Station Method
INSTALLING J-8393-02
-
1. Be ceitain compressor hand shut-off valves to
gauge fittings are closed (counterclockwise).
2. Be certain all valves on charging station are
closed.
3. Connect high pressure gauge line to compressor
high pressure gauge fitting.
4. Turn high pressure hand shut-off valve one turn
clockwise, and high pressure control one turn coun-
terclockwise (open). Crack open low pressure con-
trol and allow refrigerant gas to hiss from low
pressure gauge line for three seconds, then connect
low pressure gauge line to low pressure gauge fitting
on compressor adapter fitting. (Place J-9459 adapter
on hose, then attach adapter to gauge fitting.)
FILLING CHARGING CYLINDER
1. Open Control valve on refrigerant container.
2. Open valve on bottom of charging cylinder, al-
lowing refrigerant to enter cylinder.
3. Bleed charging cylinder to valve (behind control
panel) only as required to allow refrigerant to enter
cylinder. When refrigerant reaches desired charge
level, close valve at bottom of charging cylinder and
be certain cylinder bleed valve is closed securely.
While filling the cylinder, it will be necessary to close
the bleed valve periodically to allow boiling to sub-
side so that refrigerant level in the charging cylinder
can be accurately read.
CHARGING THE SYSTEM USING J-8393-02
1. With charging station connected, as previously
described, remove low pressure gauge line at com-
pressor adapter fitting.
2. Crack open high and low pressure control valves
on station and allow refrigerant gas to purge from
system. Purge slowly enough so, that oil does not
escape from system along with refrigerant.
3. When refrigerant flow nearly stops, connect low
pressure gauge line to
compress& adapter fitting.
4. Turn on vacuum pump and open vacuum control
valve.
5. With system purged as
abovk, run pump until
26-28 inches of vacuum is obtained Continue to run
pump for 15 minutes after the system reaches 26-28
inches vacuum.
In all evacuating procedures, the specification of
26.
28 inches of mercury vacuum is used. These figures
are only attainable at or near sea level. For each 1000
feet above sea level where this operation is being
performed, the specifications should be lowered by 1
inch. For example, at 5000 feet elevation, only 21 to
23 inches vacuum can normally be obtained.
6. If 26-28 inches vacuum (corrected to sea level)
cannot be obtained, close vacuum: control valve and

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

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

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

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