check oil OPEL GT-R 1973 Manual PDF

9B-30 1973 OPEL SERVICE MANUAL
refrigerant penetrates to every nook and cranny of
the unit.
Among the many desirable properties of R-12, is its
stability under operating conditions. However, while
more stable than the other refrigerants under the
same conditions, it, too, can be caused to form harm-
ful acids which will eventually fail the system.OilOil is the most complex of all of the organic chemi-
cals. Its stability in a refrigerating system is depend-
ent upon the source of crude oil and its method of
refining. A good refrigerating oil must be free of
sludge and gum-forming substances and free of
harmful impurities, such as sulphur. It must also be
stabilized to resist oxidation and must have a high
degree of resistance to carbonization.
The chemical properties of the lubricating oil form
another very important consideration in the chemi-
cal stability within the system. Like the refrigerant,
it travels to every nook and cranny of the unit.
The factory obtains the finest oils which have been
refined from the most desirable
crudes. It is reproc-
essed at the factory before it is charged into a system
or poured into a container for resale. Its
voscosityand flash point are checked and it is forced through
many sheets of filtering paper.
Even the containers in which it is poured for resale
are processed. As you recive it for field service it is
the cleanest, dry&, and purest oil that is humanly
possible to make. Leaving the container uncapped
even for a few minutes allows the oil to absorb mois-
ture from the air. Many system failures have been
caused by chemical reactions which were started by
servicemen adding contaminated oil.
Desiccants (Dehydrating Agent)Over the years the industry has spent hundreds of
thousands of dollars in finding and developing
chemical substances which are suitable for use in
refrigerating systems. An ideal desiccant must have
the following characteristics:
I. High capacity.
2. High eficiency.
3. Low tendency to powder.
4. Absorb moisture without reacting chemically with
it.5. Allow refrigerant to flow through it with mini-
mum restriction.
6. Retain moisture at high temperature.This has been a difficult combination to find. While
some desiccants excel in several of the desirable char-
acteristics, they are unsatisfactor:y in others.
Activated Silica Alumina, used in current
receiver-dehydrators, is a most satisfactory desiccant. How-
ever, its ability to retain moisture is affected by its
temperature. As the temperature increases, its ability
decreases. This means that moisture which is re-
tained at a lower temperature may be put back into
the system at a higher temperature.
MAINTAINING CHEMICAL STABILITY IN THE
REFRIGERATION SYSTEMThe metal internal parts of the refrigeration system
and the refrigerant and oil contained in the system
are designed to remain in a state of chemical stability
as long as pure R-12 plus refrigeration oil is used in
the system. However, when abnormal amounts of
foreign materials, such as dirt, air or moisture are
allowed to enter the system, the chemical stability
may be upset (Fig. 9B-24).
Figure
98.24 System Contaminants
When accelerated by heat, these contaminants may
form acids and sludge and eventually cause the
breakdown of components within the system. In ad-
dition, contaminants may affect the temperature
pressure relationship of R-12, resulting in improper
operating temperature and pressures and decreased
efficiency
OF the system.
The following general practices should be observed
to maintain chemical stability in the system:
Whenever it becomes necessary to disconnect a re-
frigerant or gauge line, it should be immediately
capped. Capping the tubing will also prevent dirt and
foreign matter from entering.
Tools should be kept clean and dry. This also in-
cludes the gauge set and replacement parts.

REFRIGERANT COMPONENTS ALL MODELS
99.37
in front of the radiator so that it receives a high
volume of air flow. Air passing over the condenser
absorbs the heat from the high pressure gas and
causes the refrigerant to condense into a high pres-
sure liquid.Receiver. DehydratorThe receiver-dehydrator is located in the engine
compartment. The purpose of the receiver dehydra-
tor is two fold: the unit insures a solid column of
liquid refrigerant to the expansion valve at all times,
and also absorbs any moisture in the system that
might be present. A bag of desiccant (moisture ab-
sorbing material) is provided to absorb moisture. A
sight glass (see Figure 9B-33) permits visual check-
ing of the refrigerant flow for bubbles or foam. The
continuous appearance of bubbles or foam above an
ambient temperature of 70 degrees F. usually indi-
cates an inadequate refrigerant charge. Bubbles or
foam appearing at ambient temperatures below 70
degrees F. do not necessarily indicate an inadequate
charge and may appear even when the system is
operating properly. A filter screen in the unit pre-
vents foreign material from entering the remainder
of the system.
Expansion ValveThe expansion valve is mounted on the evaporator
core inside the passenger compartment. The function
of the expansion valve is to automatically regulate
SCREEN
lLCl98.30
Figure 98-34 Expansion Valvethe flow of refrigerant into the evaporator. The ex-
pansion valve is the dividing point in the system
between the high and low pressure liquid refrigerant.
A temperature sensing bulb is connected by a capil-
lary tube to the expansion valve (see Figure
9B-34).The temperature sensing bulb (clamped to the outlet
pipe on the evaporator) measures the temperature of
the evaporator outlet pipe and transmits the temper-
ature variations to the expansion valve (see Figure
9B-34). The capillary tube and bulb are tilled with
carbon dioxide and sealed to one side of the expan-
sion valve diaphragm.
An increase in temperature will cause the carbon
dioxide in the bulb and capillary tube to expand,
overcoming the spring pressure and pushing the dia-
phragm against the operating pins (see Figure 9B-
34). This in turn will force the valve off its seat.
When the refrigerant low pressure gas flowing
through the outlet pipe of the evaporator becomes
more than 6 degrees higher or warmer than the tem-
perature at which it originally began to vaporize or
boil, the expansion valve will autmotatically allow
more refrigerant to enter evaporator. If the tempera-
ture of the low pressure gas decreases to less than 6
degrees above the temperature at which it originally
began to vaporize or boil, the expansion valve will
automatically reduce the flow of refrigerant. Thus,
an increase or decrease in the flow of refrigerant
through the evaporator will result in an increase or
decrease in the cooling by the evaporator. The tem-
perature, humidity and volume of the air passing
over the evaporator affects the rate of absorption of
heat by the evaporator. As the ambient temperature
bulb calls for more or less refrigerant will increase or
decrease. When the air is very warm, the heat trans-
fer from the air to the refrigerant is great and a
greater quantity of refrigerant is required to maintain
the temperature at the evaporator pipe at the prede-
termined value. Conversely, cool days will result in
less heat transfer and thereby require lesser quanti-
ties of refrigerant to maintain the predetermined
temperature of the evaporator outlet pipe.
EvaporatorThe function of the evaporator is to cool and
dehumidify the air flow in the passenger compart-
ment. The evaporator assembly consists of an alumi-
num core enclosed in a reinforced plastic housing.
Two (2) water drain ports are located in the bottom
of the housing. Two refrigerant lines are connected
to the side of the evaporator core: one at the bottom
and one at the top. The expansion valve is attached
to the lower (inlet) pipe, the outlet pipe is attached
to the upper pipe. The temperature sensing bulb of
the expansion valve is clamped to the outlet pipe of
the evaporator core. The high pressure liquid refrig-
erant, after it is metered through the expansion
valve, passes into the evaporator core where it is
allowed to expand under reduced pressure. As a re-
sult of the reduced pressure the refrigerant begins to

9B-38 1973 OPEL SERVICE MANUAL
expand and return to the original gaseous state. To
accomplish this transformation it begins to boil.
The boiling action of the refrigerant demands heat.
To satisfy the demand for heat, the air passing over
the core gives up heat to the evaporator and is subse-
quently cooled.\
DIAGNOSIS
GENERAL INFORMATIONThe following is a brief description of the type of
sympton each refrigerant component will evidence if
a malfunction occurs:
Compressor malfunction will appear in one of four
ways: noise, seizure, leakage, or low discharge pres-
sure.Resonant compressor noises are not cause for alarm;
however, irregular noise or rattles may indicate
broken parts or excessive clearances due to wear. To
check seizure, de-energize the magnetic clutch and
check to see if drive plate can be rotated. If rotation
is impossible, compressor is seized. Low discharge
pressure may be due to a faulty internal seal of the
compressor, or a restriction in the compressor.
Low discharge pressure may also be due to an insuffi-
cient refrigerant charge or a restriction elsewhere in
the system. These possibilities should be checked
prior to servicing the compressor. If the compressor
is inoperative; but, is not seized, check to see if cur-
rent is being supplied to the magnetic clutch coil
terminals.
CondenserA condenser may malfunction in two ways: it may
leak, or it may be restricted. A condenser restriction
will result in excessive compressor discharge pres-
sure. If a partial restriction is present, sometimes ice
or frost will form immediately after the restriction as
the refrigerant expands after pas?ing through the re-
striction. If air flow through the condenser or radia-
tor is blocked, high discharge pressures will result.
During normal condenser operation, the outlet pipe
will be slightly cooler than the inlet pipe.
Receiver-DehydratorA receiver-dehydrator may fail due to a restriction
inside body of unit. A restriction at the inlet to the
receiver-dehydrator will cause high head pressures.
Outlet tube restrictions will be indicated by low headpressures. Outlet tube restrictions will be indicated
by
low head pressures and little or no cooling. An
excessively cold receiver-dehydrator outlet may be
indicative of a restriction.
Expansion ValveExpansion valve failures usually will be indicated by
low suction and discharge pressures, and insuff%ient
evaporator cooling. The failure is generally due to
malfunction of the power element and subsequent
closing of the valve. A less common cause of the
above symptom is a clogged inlet screen.
EvaporatorWhen the evaporator malfunctions, the trouble will
show up as inadequate supply of cool air. A partially
plugged core due to dirt or a faulty blower will gener-
ally be the cause.
Refrigerant Line Restrictions
Rest~rictions in the refrigerant lines will be indicated
as follows:
I. Suction Line - A restricted suction line will cause
low suction pressure at the compressor, low dis-
charge pressure and little or no cooling.
2. Discharge Line -A restriction in the discharge line
generally will cause the pressure relief valve to open.
3. Liquid Line
- A liquid line restriction will be evi-
denced by low discharge and suction pressure, and
insufficient cooling.
Use of Receiver-Dehydrator Sight Glass for
DiagnosisAt temperatures higher than 70 degrees F, the sight
glass may indicate whether the refrigerant charge is
sufficient. A shortage of liquid refrigerant is in-
dicated after about
five minutes of compressor oper-
ation by the appearance of slow-moving bubbles
(vapor) or a broken column of refrigerant under the
glass. Continuous bubbles may appear in a properly
charged system on a cool day. This is a normal situa-
tion. If the sight, glass is generally clear and perform-
ance is satisfactory, occasional bubbles do not
indicate refrigerant shortage.
If the sight glass consistently shows foaming or a
broken liquid column, it should be observed after
partially blocking the air to the condenser. If under
this condition the sight glass clears and the perform-
ance is otherwise satisfactory, the charge shall be
considered adequate.

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.

REFRIGERANT COMPONENTS ALL MODELS9B- 43
4. Start the vacuum pump and slowly open low and
high pressure sides of manifold gauge set to avoid
forcing oil out of refrigeration system and pump,
Pressure is now being reduced on both sides of the
refrigeration system. If oil is blown from the vacuum
pump, it should be refilled to the proper level.
5. Observe low pressure gauge and operate vacuum
pump until gauge shows 28-29 inches vacuum. In all
evacuating procedures, specifications of 28-29 inchesof vacuum is used. This evacuation can only be at-
tained at or near sea level.
For each 1000 feet above sea level where this operat-ion is being-performed, the specification should be
lowered by one inch of mercury vacuum. At 5000
feet elevation, only 23 inches to 24 inches of vacuum
can normally be obtained.
If vacuum cannot be pulled to the minimum specifi-
cation for the respective altitude, it indicates a leak
in the system or gauge connections or a defective
vacuum pump. In this case, it will be necessary to
check for leaks as described under “Leak Testing
Refrigerant System”.
When specified vacuum level (28-29 inches at sea
level) is obtained, continue to run vacuum pump for
ten (10) ‘additional minutes. During these ten (10)
minutes:
A. Prepare for charging the system. If using a charg-
ing station, till charging cylinder. If using manifold
gauge set, make all preparations for charging system
as described under “Disposable Can Method” or
“Refrigerant Drum Method”.
B. Measure oil loss collected as a result of rapid
discharge.
C. Uncap compressor oil injector (J-24095) and open
valve. Flush J-24095 with refrigerant, close valve and
insert pick-up tube into graduated container of clean
refrigerant oil.
D. Con&ct J-24095 to suction fitting at the compres-
sor adapter fitting. When valve on J-24095 is opened,
the vacuum applied to the discharge side of the sys-
tem will suck oil into system from container. There-
fore,
close observation of oil level in the container is
necessary.E. Note level of oil in container. Open valve on
J-24095
u+il oil level in container is reduced by an
amount equal to that lost during discharge of system,
then shut valve. Take care not to add more oil than
was lost. ,,
F. Disconnect J-24095 and attach pick-up tube fit-
ting to schraeder fitting to cap tool. See Figure 9B-
42.J-24095
-98.32
Figure 98.42 Oil Injector J-24095
6. Turn hand shut-off valves at low and high pressure
gauges of gauge set to full clockwise position with
vacuum pump operating, then stop pump. Carefully
check low pressure gauge approximately for two (2)
minutes to see that vacuum remains constant. If
vacuum reduces, it indicates a leak in the system or
gauge connections.
Charging the SystemThe system should be charged only after being eva-cuated as outlined in “Evacuating the System”.
Refrigerant orurn Method
1. Connect center flexible line of gauge set to refriger-ant drum.
2. Place refrigerant drum in a pail of water which has
been heated to a maximum of 125 degrees F.
WARNING: Do not allow temperature of water to ex-
ceed I25
degrees E High temperature will cause
safety plugs in the refrigerant drum. It may not be
necessarv to use hot water if a /arae drum is used(over
ap)roximateIy 100 lbs.).-I3. Place refrigerant drum (in pail of water) on scales
(bathroom or commercial, perferably commercial).

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