water OPEL MANTA 1973 Workshop Manual

9B-22 1973 OPEL SERVICE MANUAL
We can change a vapor back into a liquid by chilling
it, or do the same thing with pressure. When we
condense a vapor we will find that the heat removed
just exactly equals the amount of heat that was neces-
sary to make the substance vaporize in the first place.
At last the lost is found! The latent heat of vaporiza-
tion the heat that apparently disappeared when
a liquid boiled into a vapor again reappears on
the scene when that same vapor reverts back into a
liquid. It is just like putting air into a balloon to
expand it and then letting the same amount of air out
again to return the balloon to its original condition.
We know that any substance will condense at the
same temperature at which it boiled. This tempera-
ture point is a clear-cut division like a fence. On one
side, a substance is a liquid. Immediately on the
other side it is a vapor. Whichever way a substance
would go, from hot to cold or cold to hot, it will
change its character the moment it crosses over thefence.But pressure moves the fence! Water will boil at 212
degrees under normal conditions. Naturally, we ex-
pect steam to condense at the same temperature. But
whenever we put pressure on steam, it doesn’t! It will
condense at some temperature higher than 212 de-
grees. The greater the pressure, the higher the boiling
point and the temperature at which a vapor will
condense. This is the reason why pressure cookers
cook food faster, since the pressure on the water
permits it to boil out at a higher temperature. We
know that R-12 boils at 21.7 degrees below zero. A
thermometer will show us that the rising vapors,
even though they have soaked up lots of heat, are
only slightly warmer. But the vapors must be made
warmer than the room air if we expect heat to flow
out of them. Also, the condensing point temperature
must be above that of room air or else the vapors
won’t condense.This is where pressure comes to the rescue. With
pressure, we can compress the vapor, thereby con-
centrating the heat it contains. When we concentrate
heat in a vapor that way, we increase the intensity of
the heat or, in other words, we increase the tempera-ture;because temperature is merely a measurement
of heat intensity. And the most amazing part of it all
is that we’ve made the vapor hotter without actually
adding any additional quantity of heat (Fig.
9B-12).
Use of Pressure in RefrigerationBecause we must live by press&s and gauges in air
conditioning work, the following points are men-
tioned so that we will all be talking about the same
thing when we speak of pressures.
All pressure, regardless of how it is produced, is
measured in pounds per square inch (psi).Figure 98.12 Compressing a Vapor Concentrates its
HeatAtmospheric Pressure is pressure exerted in every
direction by the weight of the atmosphere. At higher
altitudes air is raritied and has less weight. At sea
level atmospheric pressure is 14.7 psi.
Any pressure less than atmospheric is known as a
partial vacuum or commonly called a vacuum. A
perfect vacuum or region of no pressure has never
been mechanically produced. Gauge pressure is used
in refrigeration work. Gauges are calibrated in
pounds (psi) of pressure and inches of Mercury for
vacuum. At sea level
“0” lbs. gauge pressure is
equivalent to 14.7 lbs. atmospheric pressure. Pres-
sure greater than atmospheric is measured in pounds
(psi) and pressure below atmospheric is measured in
inches of vacuum. The “0” on the gauge will always
correspond to the surrounding atmospheric pressure,
regardless of the elevation where the gauge is being
used.
Basic Refrigerator OperationWe’ve now covered all the ground-rules that apply to
refrigeration. Most likely they still are a little hazy,
but it is easy enough to remember these main points.
All liquids soak up lots of heat without getting any
warmer when they boil into a vapor, and, we can use
pressure to make the vapor condense back into a
liquid so it can be used over again. With just that
amount of knowledge, here is how we can build a
refrigerator.
We can place a flask of refrigerant in an ice-box. We
know it will boil at a very cold temperature and will
draw heat away from everything inside the cabinet
(Fig. 9B-13).
We can pipe the rising vapors outside the cabinet and
thus provide a way for carrying the heat out. Once

REFRIGERANT COMPONENTS ALL MODELS96.23Figure 96-l 3 Basic Refrigerant Circuit
we get the heat-laden vapor outside, we can com-
press it with a pump. With enough pressure, we can
squeeze the heat out of “cold” vapor even in a warm
room. An ordinary.radiator will help us get rid of
heat.
By removing the heat, and making the refrigerant
into a liquid, it becomes the same as it was before, So,
we can run another pipe back into the cabinet and
return the refrigerant to the flask to be used over
again.
That is the way most mechanical refrigerators work
today. Now, let’s look at an air conditioning unit to
see how closely it resembles the refrigerator we have
just described.
Basic Air ConditionerWhen we look at an air conditioning unit, we will
always find a set of coils or a tinned radiator core
through which the air to be cooled passes. This is
known as the “evaporator” (Fig.
9B-14). It does the
same job as the flask of refrigerant we
spok.e about
earlier. The refrigerant boils in the evaporator. In
boiling, of course, the refrigerant absorbs heat and
changes into a vapor. By piping this vapor outside
the car we can bodily carry out the heat that caused
its creation.
Once we get vapor out of the evaporator, all we haveFigure 98.14 Evaporator Assembly
to do is remove the heat it contains. Since heat is the
only thing that expanded the refrigerant from a liq-
uid to a vapor in the first place, removal of that same
heat will let the vapor condense into a liquid again.
Then we can return the liquid refrigerant to the
evaporator to be used over again.
Actually, the vapor coming out of the evaporator is
very cold. We know the liquid refrigerant boils at
temperatures considerably below freezing and that
the vapors arising from it are only a shade warmer
even though they do contain quantities of heat.
Consequently, we can’t expect to remove heat from
sub- freezing vapors by “cooling” them in air tem-
peratures that usually range between 60 and 100
degrees heat refuses to
flow from a cold object
toward a warmer object.
But with a pump, we can squeeze the heat-laden
vapor into a smaller space. And, when we compress
the vapor, we also concentrate the heat it contains.
In this way, we can make the vapor hotter without
adding any heat. Then we can cool it in compara-
tively warm air.
That is the only responsibility of a compressor in an
air conditioning system (Fig.
9B-15). It is not in-
tended to be a pump just for circulating the refriger-
ant. Rather, its job is to exert pressure for two
reasons. Pressure makes the vapor hot enough to
cool off in warm air. At the same time, the compres-
sor raises the refrigerant’s pressure above the con-
densing point at the temperature of the surrounding
air so it will condense.
As the refrigerant leaves the compressor, it is still a
vapor although it is now quite hot and ready to give
up the heat that is absorbed in the evaporator. One
of the easiest ways to help refrigerant vapor dis-
charge its heat is to send it through a radiator- like
contrivance known as a condenser (Fig. 9B-16).
The condenser really is a very simple device having
no moving parts. It does exactly the same job as the
radiator in a typical steam-heating system. There,
the steam is nothing more than water vapor. In pass-
ing through the radiator, the steam gives up its heat
and condenses back into water.
The same action takes place in an air conditioning

98-26 1973 OPEL SERVICE MANUAL
greater than the opposing pressure in the power ele-
ment. Therefore, the valve remains closed. When the
compressor is started, it will reduce the pressure and
temperature of the refrigerant in the cooling coil to
a point where the vapor pressure in the power ele-
ment becomes the stronger. The seat then moves off
the orifice and liquid starts to flow through the valve
orifice into the cooling coil.
The purpose of the power element is to help deter-
mine the quantity of liquid that is being metered into
the cooling coil. As the temperature of the low pres-
sure line changes at the bulb, the pressure of
the
vapor in the power element changes, resulting in a
change of the position of the seat. For example, if the
cooling coil gets more liquid than is required, the
temperature of the low pressure line is reduced and
the resultant lowering of the bulb temperature
reduces the pressure of the vapor in the power ele-
ment, allowing the seat to move closer to the orifice.
This immediately reduces the amount of liquid leav-
ing the valve. Under normal operation, the power
element provides accurate control of the quantity of
refrigerant to the cooling coil.
To employ our tire pump analogy once more for
clarity, it is the same situation that would exist if you were inflating a tire with a very slow leak. Providing
you pumped the air into the tire as fast as it leaked
out, you would be able to maintain pressure even
though the air would merely be circulating through the tire and leaking out through the puncture.
To Sum Up
So far, we’ve discussed only what each unit in an air
conditioning system does. We’ve learned that the
evaporator is the unit in which liquid refrigerant
soaks up heat from the air, the compressor is a pump
for squeezing this heat out of the vapor, the con-
denser is a radiator for getting rid of the heat, and the
thermostatic expansion valve is a device for regulat-
ing the pressure on the refrigerant. Now, let’s
find
out how the temperature of the cooled air is con-
trolled.
METHOD OF TEMPERATURE CONTROL
To achieve temperature control, the compressor is
run intermittently, automatically turning on and off
as necessary to maintain proper temperature.
Thermostatic Switch
The compressor can be started and stopped au-
tomatically through the use of an electro-magnetic
clutch and a thermostat affected by variations of temperature.
The job is usually done by a gas bulb thermostat (Fig.
9B-21).
Figure 9B-21 Thermostatic Switch Schematic
With the gas bulb type of thermostat, a highly expan-
sive gas is sealed into a metallic bulb which is located
in the air stream as it leaves the evaporator. A small
tube leads from the bulb to a bellows operated switch. As air temperature rises, the gas inside the
bulb expands, travels through the tube to the bellows
and closes the electrical switch that engages the com-
pressor clutch.
Of course, as soon as the compressor starts running,
the temperature begins to go down. As the air being
cooled gets colder, the gas in the thermostat bulb
begins to reduce the pressure on the switch bellows.
This
Ilips “off’ the switch and disengages the com-
pressor clutch.
REFRIGERANTS
No matter how scientifically refrigerating machinery
is built or how
efftciently it runs, it alone cannot
remove heat. The only thing that carries heat out of
a refrigerator cabinet or an automobile is the sub-
stance we call the refrigerant.
There are many refrigerants known to man. In fact,
any liquid that can boil at temperatures somewhere
near the freezing point of water can be used.
But a boiling point below the temperature at which
ice forms is not the only thing that makes a good
refrigerant. A refrigerant should also be non-
poiso-
nowand non-explosive to be safe. Besides that, we
want a refrigerant that is non-corrosive and one that
will mix with oil.
Since Nature did not provide an ideal refrigerant,
chemists went to work to see if they could do any
better. They did! But it wasn’t as simple as that.
At first, they tried to improve existing natural refrig-
erants. But after exploring innumerable trails along

REFRIGERANT COMPONENTS ALL MODELS99.27that line, they still hadn’t gotten anywhere. So, they
started from scratch and juggled molecules around
to make an entirely new refrigerant. Eventually they
succeeded by remodeling the molecules in carbon
tetrachloride. This is the same fluid that is used in
fire extinguishers and dry-cleaners’ solvents.
From this fluid, the chemists removed two chlorine
atoms and replaced them with two fluorine atoms.
This newly-formed fluid carried the technical chemi-
cal name of dichlorodifluoromethane. Today, we
know it as Refrigerant-12 or R-12.
Fluorine is an extremely temperamental substance.
Under most conditions it is toxic and highly corro-
sive, and after is is manufactured, it has to be stored
in special containers because it will eat through glass
and will dissolve most metals in short order.
Despite its rambunctious character though, fluorine
is completely tamed when it is combined with the
other substances that go to make up the refrigerant.
Each is non-toxic, non-inflammable, non-explosive,
and non- poisonous; however, breathing large quan-
tities of R-12 should be avoided.
Pressure. Temperature Relationship of R-12A definite pressure and temperature relationship ex-
ists in the case of liquid refrigerants and their satu-
rated vapors. Increasing the temperature of a
substance causes it to expand. When the substance is
confined in a closed container, the increase in tem-
perature will be accompanied by an increase in pres-
sure, even though no mechanical device was used.
For every temperature, there will be a corresponding
pressure within the container of refrigerant. A table
of the temperature-pressure relationship of R-12 is
presented below. Pressures are indicated in gauge
pressure, either positive pressure (above atmos-
pheric) m pounds or negative pressure (below atmos-
pheric) in inches of vacuum.
“F-40
-35
i#Pressure
11.0*
8.3*
“F
50
50#Pressure
46.1
52.0
-30~
5.5*6057.7
-252.3*6s67 7__.
-200.6
io70.1
-152.4
76.9
-104.584.1
1;6.8 9.2tz99.6 91.71;
11.8 14.712116.9 108.1
1517.7105126.2
2021.1110136.0
2524.6115146.5
3028.5120157.1
;:
30.1
125167.5
32.6
131)179n
4037.0
4541.7*Inches of Vacuum.-. _.-
1402045
150232.0Thus if a gauge is attached to a container of R- 12 and
the room temperature is 70 degrees, the gauge will
register 70 psi pressure; in a 100 degrees room the
pressure will be 117
ps~
AIR CONDITIONINGBecause air conditioning has always been very
closely allied with mechanical refrigeration, most of
us are apt to think of it only as a process for cooling
room air.
But true air conditioning goes beyond the mere cool-
ing of the air. It controls the humidity, cleanliness,
and circulation of the air as well.
Whenever it gets warm and muggy in the summer-
time, someone is almost sure to say, “It’s not the heat
it’s the humidity.” But that is only partly right.
Actually it is a combination of the two that makes us
feel so warm temperature alone is not the only
thing that makes us uncomfortable.
Humidity is nothing more nor less that the moisture
content of the air. To a certain extent, it is tied in
with the temperature of the air. Warm air will hold
more moisture than will cold air. When air contains
all the moisture it can hold, we say it is saturated,
and the relative humidity is 100 percent. If the air
contains only half as much water as it could possibly
hold at any given temperature, we say that the rela-
tive humidity is 50 percent. If it contains only a fifth
of its maximum capacity, we say that the relative
humidity is 20 percent and so on. This amount
of water vapor, or relative humidity, affects the way
we perspire on hot days.
Nature has equipped our bodies with a network of
sweat glands that carry perspiration to the skin
sur-faces. Normally, this perspiration evaporates and, in
doing so, absorbs heat just like a refrigerant absorbs
heat when it is vaporized in a freezer. Most of the
heat thus absorbed is drawn from our bodies, giving
us a sensation of coolness. A drop of alcohol on the
back of your hand will demonstrate this principle
very convincingly. Because it is highly volatile, al-
cohol will evaporate very rapidly and absorb quite a
bit of heat in doing so, thereby making the spot on
your hand feel unusually cool.
The ease and rapidity with which evaporation takes
place, whether it be alcohol or perspiration, governs
our sensation of coolness and to a certain extent,
independently of the temperature. Of even more im-
portance, the ease and rapidity of the evaporation are
directly affected by the relative humidity or com-
parative dampness of the air. When the air is dry,
perspiration will evaporate quite readily. But when
the air contains a lot of moisture, perspiration will
evaporate more slowly; consequently less heat is car-
ried away from our body.

REFRIGERANT COMPONENTS ALL MODELS99- 33
That the attraction of the drying material for mois-
ture is so powerful that if the receiver is left open,
moisture will be drawn in from the outside air.
That just one drop of water added to the refrigerantwill start chemical changes that can result in corro-
sion and eventual breakdown of the chemicals in the
system. Hydrochloric acid is the result of an R-12
mixture with water.
That the smallest amount of air in the refrigeration
system may start reactions that can cause malfunc-
tions.
That the drying agent in the receiver-dehydrator is
Activated Silica Alumina (silica-gel).
That
the inert gas in the expansion valve capillary
line is carbon dioxide.
DESCRIPTION OF AIR CONDITIONING
COMPONENTS
Compressor
The compressor is located in the engine compart-
ment. The purpose of the unit is to draw the low
pressure,gas from the evaporator and compress this
gas into a high temperature, high pressure gas. This
action will result in the refrigerant having a higher
temperature than the surrounding air.
The
cortipressor is of basic double action piston de-
sign. Three horizontal double acting pistons make up
a six cylinder compressor (See Figure
9B-162). The
pistons operate in
l-1/2 inch bore and have a l-1/8
inch stroke. A
wash plate keyed to the shaft drives
the pistons. The shaft is belt driven through a mag-
netic clutch and pulley arrangement. An oil pump
mounted at the rear of the compressor picks up oil
from the
botto’m of the compressor and lubricates the
bearings’and other internal parts of the compressor.
Reed type valves at each end of the compressor open
or close to control the flow of incoming and outgoing refrigerant. Two gas tight passages interconnect
chambers of the front and rear heads so that there is
one common suction port, and one common dis-
charge port. The internal parts of the compressor
function, as follows:
1. Suction Valve Reed Discs and Discharge Valve
Plates
_ The two suction valve reed discs and two
discharge valve plates (see Figure
9B-25) operate in
a similar but opposite manner. The discs are com-
posed of three reeds and function to open when the
pistons are on the intake portion of their stroke
(downstroke), and close on the compression stroke.
The reeds allow low pressure gas to enter the cylin- ders. The discharge valve plates also have three
reeds, however, they function to open when the pis- tons are on the compression portion of their stroke
(upstroke), and close on the intake stroke. High pres-
sure gas exits from discharge ports in the discharge
valve plate. Three retainers riveted directly above the
reeds on the valve plate serve to limit the opening of
the reeds on the compression stroke.
SUCTION VALVE
DISCHARGE-VALVE PLATES
Figure
98-25 - Compressor Suction Valve Reed Discs
and Discharge Valve Plates
2. Front and Rear Heads - The front and rear heads
(Figure
9B-26) serve to channel the refrigerant into
and out of the cylinders. The front head is divided
into two separate passages and the rear head is di-
vided into three separate passages. The outer passage
on both the front and rear heads channels high pres-
sure gas from the discharge valve reeds. The middle
passage of the rear head also contains the port open-
ing to the superheat switch cavity. This opening in
the rear head permits the superheat switch to be
affected by suction gas pressure and suction gas tem-
perature for the operating protection of the compres-
sor. The inner passage on the rear head houses the
oil pump inner and outer rotors. A Teflon sealing
material is bonded to the sealing surfaces separating
the passages in the rear head.
“0” rings are used to
affect a seal between the mating surfaces of the heads
and the shell. The front head suction and discharge
passages are connected to the suction and discharge
passages of the rear head by a discharge tube and
suction passage in the
body of the cylinder assembly.
A screen located in the suction port of the rear head
prevents foreign material from entering the circuit.
3. Oil Pump
- An internal tooth outer rotor and
external tooth inner rotor comprise the oil pump.
The pump works on the principle of a rotary type pump. Oil is drawn up from oil reservoir in underside
of shell through the oil inlet tube (see Figure
9B-27)

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

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).

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.
.

SubjectPage Number1
Throttle Linkage Adjustment........,:.......6E-51
Timing Chain Cover.......................6A-23
Timing Chain and Sprocket.........
':.......6A-23
Tires...................................36-55
Inflation.....................
.;.......3G-62
Rotation.............................36-57
Sizes.........................
........3G-62
Track Rod..............................3F-53
Transmission Oil Pan
Automatic Transmission.................7C-99
Transmission Reassembly
4 Speed Manual. 1.9.....................76-28Tranmission Removal and Installation
4 Speed Manual
Removal...........................7B-22
Installation.........................76-22
Auto&tic............................7c-94Tune’Up Procedure........................66-65
Torque Specifications. Engine...............6A-27
Turn Signal See Directional Signal
Universal Joints..........................4A-3Subject
VPage Number
Vacuum Modulator..7C-101
Valve Body Transmlssmn7C.99
Valve and Seat Reconditioning Engine6A-12
WWater Pump Engine1.9L Engine
Wheels
Wheel Alignment
Whee! Bearing, Adjustment,
Windshield Wiper and Washer:
Trouble Diagnosis:Description and Operation
Removal and Installation
Specifications
Wiring Diagrams Complete
Opel 1900 ._.
Manta
GT
1 E-37
1 E-37
1 E-38
1 E-43
1 J-l 03
1 J-l 05lJ-10768-3436-553C-223A-4