1973 OPEL GT-R ESP

REFRIGERANT COMPONENTS ALL MODELS9B- 31
When adding oil, the container should be exception-
ally clean and dry due to the fact that the refrigera-
tion oil in the container is as moisture-free as it is
possible to make it. Therefore, it will quickly absorb
any moisture with which it comes in contact. For this
same reason the oil container should not be opened
until ready for use and it should be capped immedi-
ately afte;r use.
When it is necessary to open a system, have every-
thing you will need ready and handy so that as little
time as possible will be required to perform the oper-
ation. Don’t leave the system open any longer than
is necessary.
Finally, after the operation has been completed and
the system sealed again, air and moisture should be
evacuated from the system before recharging.
THE PRIMARY CAUSES OF SYSTEM FAILURES
LeaksA shortage of refrigerant causes oil to be trapped in
the evaporator. Oil may be lost with the refrigerant
at point of leakage. Both of these can cause compres-
sor seizure.
Oil circulates in the system with the refrigerant; in
solution with the liquid and in globules with the
vapor. It leaves the compressor by the action of the
pistons and mixes with the refrigerant liquid in the
condenser. The oil then enters the evaporator with
the liquid and, with the evaporator properly flooded,
is returned to the compressor through the low pres-
sure line. Some of the oil returns as globules in the
vapor, but more important, it is swept as a liquid
along the walls of the tubing by the velocity of the
vapor. If the evaporator is starved, the oil cannot
return in sut?icient quantities to keep the compressor
properly lubricated.
High Temperature and PressureAn increase in temperature causes an increase in
pressure. This accelerates chemical instability due to
existing contaminants in the system, and initiates
chemical instability in clean systems. Other results
are brittle hoses,
“0” ring gaskets, and valve dia-
phragms with possible decomposition, broken com-
pressor discharge reeds, and seized compressor
bearings.
A fundamental law of nature accounts for the fact
that when a substance, such as a refrigerant, is in-
creased in temperature, its pressure is also increased.
Any chemical reactions caused by contaminants al-
ready in the system are greatly accelerated as the
temperature increases. A 15 degree rise in tempera-
ture doubles the chemical action. Even in a goodclean system, heat alone can start a chain of harmful
chemical reactions.
While temperature alone can cause the synthetic rub-
ber parts to become brittle and possibly to decom-
pose, the increased pressure can cause them to
rupture or blow.
As the temperature and pressure increases the stress
and strain on the compressor discharge reeds also
increases. This can result in broken reeds. Due to the
effect of the contaminants caused by high tempera-
ture and pressure, compressor bearings can be
caused to seize.
High temperature and pressure are also caused by air
in the system.
Air in the SYstemAir results from a discharged system or careless ser-
vicing procedures. This reduces system capacity and
efficiency and causes oxidation of oil into gum and
varnish.
When a leak causes the system to become dis-
charged, the resulting vacuum within the system will
cause air to be drawn in. Air in the system is a
non-condensable gas and will build up in the con-
denser as it would in an air compressor tank. The
resultant heat produced will contribute to the condi-
tions discussed previously.
Many systems are contaminated and also reduced in
capacity and efficiency by servicemen who either do
not know or are careless regarding proper servicing
procedures.
Too frequently, systems which have been open to the
atmosphere during service operations have not been
properly purged or evacuated. Air is also introduced
into the system by unpurged gauge and charging
lines. Remember that any air in the system is too
much air.
Poor ConnectionsHose clamp type fittings must be properly made.
Hoses should be installed over the sealing flanges and
with the end of the hose at the stop flange. The hose
should never extend beyond the stop flange. Locate
the clamp properly and torque as recommended. Be
especially careful that the sealing flanges are not
nicked or scored or a future leak will result.
When compression fittings are used, over tightening
can cause physical damage to the “0” ring gasket
and will result in leaks. The use of torque and back-
ing wrenches is highly recommended. When making
a connection with compression fittings, the gaskets
should always be first placed over the tube before

98-32 1973 OPEL SERVICE MANUAL
inserting it in the connection. Another precaution -inspect the fitting for burrs which can cut the
“0”ring.
Restrictions
Restrictions may be due to powdered desiccant or
dirt and foreign matter. This may result in starved
evaporator and loss of cooling, or a seized compres-
SOT.When the amount of moisture in a system sufti-
ciently exceeds the capacity of the desiccant, it can
break down the desiccant and cause it to powder.
The powder passes through the dehydrator screen
with the refrigerant liquid and is carried to the ex-
pansion valve screen. While some of it may pass
through the valve screen into the evaporator, it may
quickly build up to cause a restriction.
Due to the fact that sufftcient oil can not be returned
to the compressor, it may seize.
Dirt
Dirt, which is any foreign material, may come from
cleaner residues, cutting, machining, or preserving
oils, metal dust or chips, lint or dust, loose rust,
soldering or brazing fluxes, paint or loose oxide
scale. These can also cause seized bearings by abra-
sion or wedging, discharge and expansion valve fail-
ure, decomposition of refrigerant and oil, or
corrosion of metal parts.
CorrosionCorrosion and its by-products can restrict valve and
drier screens, rough bearing surfaces or rapid fatigu-
ing of discharge reeds. This can result in high tem-
perature and pressure, decomposition or leaks. In
any event, this means a wrecked compressor.
From this, we can see the vicious circle that can be
produced in a refrigerating system to cause its fail-
ure. Corrosion can be the indirect cause of leaks, and
leaks can be the direct cause of corrosion. We can
also see the important role we as servicemen play in
maintaining chemical stability.
The major cause of corrosion is moisture.
Moisture
Moisture is the greatest enemy of refrigerating sys-
tems. Combined with metal, it produces oxide, Iron
Hydroxide and Aluminum Hydroxide. Combined
with R-12 it produces Carbonic acid, Hydrochloric
acid, and Hydrofluoric acid. Moisture can also cause
freeze-up of expansion valve and powdered desic-
cant.Although high temperature and dirt are responsible
for many difficulties in refrigerating systems, in most
instances it is the presence of moisture in the system
that accelerates these conditions. It can be said,themfore, that moisture is the greatest enemy of all.
The acids that it produces, in combination with both
the metals and the refrigerant, cause damaging
COT-
rosion. While the corrosion may not form as rapidly
with R-12 as with some other refrigerants, the even-
tual formation is as damaging.
If the operating pressure and temperature in the
evaporator is reduced to the freezing point, moisture
in the refrigerant can collect at the orifice of the
expansion valve and freeze. This temporarily re-
stricts the flow of liquid causing erratic cooling.
As previously mentioned, moisture in excess of the
desiccant’s capacity can cause it to powder.
YOU SHOULD KNOW AND REMEMBER..That the inside of the refrigerat,ion system is com-
pletely sealed from the outside world. And if that
seal remains broken at any point
- the system will
soon be destroyed. That complete and positive seal-
ing of the entire system is vitally important and that
this sealed condition is absolutely necessary to retain
the chemicals and keep them in a pure and proper
condition.
That all parts of the refrigeration system are under
pressure at all times, whether operating or idle, and
that any leakage. points are continuously losing re-
frigerant and oil.
That the leakage of refrigerant can be so silent that
the complete charge may be lost without warning.
That refrigerant gas is heavier than air and will rap-
idly drop to the floor as it flows from a point of
leakage.
That the pressure in the system may momentarily
become as high as 400 lbs. per square inch, and that
under such pressure the molecules of refrigerant are
forced out through the smallest opening or pore.
That the compressor is continually giving up some
lubricating oil to the circulating refrigerant and de-
pends upon oil in the returning refrigerant for con-
tinuous replenishment. Any stoppage or major loss
of refrigerant will therefore be fatal to the compres-
SOT.That the extreme internal dryness of a properly proc-
essed system is a truly desert condition, with the
drying material in the receiver holding tightly on to
the tiny droplets of residual moisture.

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).

REI:RIGERANT COMPONENTS ALL MODELS9s. 71
/Figure 9%128 Removing Internal Cylinder Assembly
Figure 9B-130 Removing Front Head
If sealing surfaces of front head (see Figure 9B- 13 1)
are damaged, replace front head. There is no Teflon
on front head sealing surface.
Disassembly of Cylinder Assembly1. Pry off suction pass cover using screwdriver (see
Figure
9B-132).2. Placevzylinder assembly (front end downward)
on top of compressing fixture (J-9397), number pis-
tons and cylinders “1, 2 and 3” to facilitate reassem-
bly (see Figure
9B-133), and separate cylinder halves
using a hard rubber mallet or hammer and wood
block.
SEALINGFigure 96.131 Front Head Sealing Surfaces
SUCTION
PASS COVERFigure 98-132 Removing Suction Pass Cover
3. Disassemble rear cylinder half and discharge
tube from cylinder assembly and discard discharge
tube.Depending on whether or not discharge tube comes
out with rear cylinder half or remains in front cylin-
der half it may be necessary to rotate shaft and wash
plate assembly (using a 9/16 inch opened wrench on
shaft seal portion of shaft) to achieve necessary clear-kl”Ct?.
4. Carefully disassemble from cylinder assembly
(see Figure 9B-134) and lay in respective place on

98.74 1973 OPEL SERVICE MANUAL
(a) Using a feeler gage, select a leaf or combination
of leaves which result in satisfactory “feel” when
inserted between rear piston drive ball and wash
plate (see Figures 9B-141 and 9B-142).CHECi(lNG?OR
SHAFT END PLAY
CHE&NG FOR
PISTON PLAY
98113Figure 98-141 Checking Piston and Shaft End Play
Figure 98-142 Checking Clearance Between Rear
Piston Drive Ball and Swash Plate(b) Remove selected leaf or leaves from feeler gage
and attach end of spring scale that is calibrated in
ounces. (A generator brush spring scale (J-5 184) or
the spring scale for checking distributor point setting
may be used for this step).
(c) Reinsert feeler gage leaf or leaves between rearpiston drive ball and wash plate and draw leaf or
leaves out again, simultaneously measuring “drag”
on leaf or leaves (see Figure
9B-143). If correct leaf
(leaves) has been selected, spring
:scale will read be-
tween 4 to 8 ounces pull (the higher reading is
desired). To perform this step correctly, feeler gage
leaf (leaves) must be withdrawn straight out with a
steady even motion, and all surfaces involved must
be coated with No. 525 viscosity oil. Record gage
dimension.
Y
i15Figure 98.143 Checking Drag
on Selected Feeler
Gage Leaf with Spring Scale
Use of the spring scale establishes a standard of
measurement of the amount of feeler gage leaf
“drag” required.
(d) Rotate the shaft and wash plate assembly 120
degrees and perform a second check (Steps “a, b and
c”) between same piston drive ball and wash plate.
Record gage dimension.
(e) Rotate shaft and wash plate again approximately
120 degrees and repeat third check (Steps “a, b and
c”) between same piston drive ball and wash plate.
Record gage dimension.(0 From the three recorded checks (Steps
“c, d and
e”) select minimum feeler gage reading and obtain
from
stock (ref. to the Shoe Disc Table for part num-
ber of shoe disc) one shoe disc corresponding to the
minimum gage reading (ref. example below). Place
shoe disc in respective position on parts tray
(J-
9402).

9B-76 1973 OPEL SERVICE MANUAL
race. If, for example a feeler gage reading of 0.009
inch results, a thrust race with a number “9”,
stamped on it should be selected.Thrust Race TableSERVICEID NO.THICK-
PART NO. ON RACE
NESS
6556000
0.0920
6556050
5.09656556055
5l/2.09706556060
6.0975
65560656
l/2.09806556070
7.0985
6556075
7l/2.09906556080
8.0995
6556085
8l/2.lOOO6556090
T/2,100s
65560959.lOlO
655610010,101s
655610510 l/2.10206556110
.10256556115
11111/2.10306556120
12.1035The selected thrust race will replace only the “zero”
outer rear thrust race. The remaining three “zero”
thrust races will remain as part of the cylinder assem-
bly.
13. Remove cylinder assembly from inside compress-
ing fixture (J-9397), place on top of compressing
fixture (see Figure 9B-133) and disassemble rear cyl-
inder from front cylinder using rubber mallet or
hammer and wood block.
14. Carefully disassemble one piston at a time from
front cylinder and lay piston, front and rear piston
drive balls and front “zero” shoe disc in respective
slot of parts tray (J-9402). To disassemble, rotatewash plate until piston is at highest point, raise awash plate approximately
l/2 inch and lift out pis-
ton and related parts, one at a time.
15. Remove outer rear ‘?ero” thrust race from shaft
and set it aside for future gaging procedures.
16. Remove previously selected outer rear thrust
race from parts tray, lightly coat with clear pe-
troleum jelly and assemble onto shaft.
Final Reassembly of Cylinder Assembly1. Reassemble piston rings (if service pistons) onto
pistons (ring scraper groove toward center of piston)
and rotate ring so that break or gap in ring can be
squeezed together when piston is being inserted into
cylinder bore.
2. Reassemble piston drive balls, “zero” and se-lected shoe discs onto No. “1” piston, and apply
clear petroleum jelly to piston pockets and shoe discs
so that balls and discs stick to piston. BE SURE to
reassemble balls and shoe discs into their specific
positions on front and rear of piston.
3. Rotate shaft and wash plate assembly until high
point of wash plate is over No. “1” cylinder bore.
Position No. “1” piston onto wash plate (see Figure9B-146) and lower the piston and wash plate so that
the front end (notched end) of the piston enters the
cylinder bore.XTED OUTER
/REAR ZERO
THRUST RACE
PISTON RINGGAP SHOULD BE
TOWARD
98-118Figure 98.146 Installing Piston Assembly in Front
Cvlinder Half - Service Pistons Shown
Figure 98.147 Compressing Front Piston Rings
-Service Pistons