1973 OPEL GT-R low oil pressure

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.
.

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