1973 OPEL GT-R warning light

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WIRING DIAGRAMS15.79
IIFigure lJ-6
Oil. Fuel. Temp. Tach, Stop and Brake Warning Light. GT
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5B- 141973 OPEL SERVICE MANUALConditionPossible CauseCorrection2. Partial system failure.2. Check front and rear brake system
and repair, if necessary. Also, check
brake warning light, if a failed
system is found and light did not
function.
3. Excessively worn shoe
and lining.3. Check and replace in axle sets.
4. Piston in caliper stuck
or sluggish.4. Remove caliper and rebuild.
5. Fading brakes due to
incorrect lining.
6. Vacuum leak.5. Remove and replace with original
equipment lining.
6. Check for ruptured hose or loose
attachment.
Excessive Pedal Travel1. Partial brake system
failure.1. Check both front and rear system
for a failure and repair. Also, check
warning light
- it should have indi-
cated a failure.
2. Insufficient fluid in
master cylinder.
3. Poor rear brake
adjustment.2. Fill reservoirs with approved
brake fluid. Check for leaks.
3. Adjust rear brake per
specifications.
4. Air trapped in system.4. Bleed system.
5. Bent shoe and lining.5. Replace axle set of shoe and
lining.
Dragging Brakes (A very
light drag is present in
all disc brakes
immediately after pedal
is released.)1. Master cylinder pistons
not returning correctly.1. With reservoir cover off, check
for fluid spurt at bypass holes as
pedal is depressed. Adjust push rod,
if necessary, or rebuild master
cylinder.
2. Restricted brake tubes2. Check for soft hoses or damaged
or hoses.tubes and replace with new hoses and
new double-walled steel brake tubing.
3. Incorrect parking brake
adjustment on rear brakes.3. Check and readjust to correct
specifications.
Grabbing or Uneven Braking
Action (All conditions
listed under “Pulls”
.)4. Check valve installed in
outlet to front disc brakes.
1. Malfunction of power
brake unit.4. Check master cylinder outlet and
remove check valve if present.
1. Check operation and repair, if
necessary.

COOLING SYSTEM6B- 33
remove drain plug on right.side of cylinder block. Set
heater temperature control valve at full heat posi-
tion. After the cooling system is drained, and plugs
reinstalled, fill the system with clean water. Run the
engine long enough to open the thermostat for com-
plete circulation through the system, then com-
pletely drain the cooling system before sediment has
a chance to settle.
Conditioning the Cooling System
“Rust Inhibitor and Stop Leak”, or equivalent listed
under Group 8.800 is recommended for use in the
cooling system, particularly when preparing for in-
stallation of anti-freeze solution. This material stops
small seepage leaks, has rust preventive properties
and its soluble oil is effective in eliminating a squeal-
ing noise which sometimes develops at the water
pump seal washer. Instructions for its application are
printed on the conditioner bottle.
It is very important to make certain that the cooling
system is properly prepared before an anti-freeze so-
lution is installed, otherwise loss of solution through
leakage may occur or seepage may result in damage
to the engine. The cooling system should be drained
and flushed as described under Draining and Flush-
ing Cooling System. All joints should be checked for
leakage and corrected, and the conditioner described
above should be added with the anti-freeze solution.
Inspect the water pump, radiator core, heater and
defroster cores, water jacket plugs, and edge of cylin-
der head gaskets for evidence of water leaks. Tighten
all hose clamps in the cooling and heating systems
and replace any deteriorated hoses.
Using and Testing Anti-Freeze
Solutions
Inhibited year around (ethylene glycol type) engine
coolant solution which is formulated to withstand
two full calendar years of normal operation without
draining or adding inhibitors should be used at all
times. Freeze protection should be provided to pro-
tect against corrosion. When adding solution due to
loss of coolant for any reason or in areas where tem-
peratures lower than minus 20 degrees F. may be
encountered, a sufficient amount of any of the sev-
eral brands of year around coolant (Ethylene Glycol
base) compatible to GM Specification 1899-M avail-
able on the market should be used. Water or alcohol
base coolants are not recommended for this vehicle
at any time.
If for any reason water only is used as a coolant in
an emergency, it is extremely important that Buick
Heavy Duty Cooling System Protector and Water
Pump Lubricant or equivalent be added to the cool-
ing system as soon as possible. If any other cooling
System protector is used, be certain it is labeled toindicate that it meets General Motors Specification
GM 1894-M. It should be recognized that this is only
a temporary measure. The manufacture intends that
permanent type coolant solution be used year around
in the cooling system.
The cooling system should be completely drained
and the recommended coolant installed every two (2)years.It is advisable to test the anti-freeze solution at inter-
vals during the winter to make certain that the solu-
tion has not been weakened. Use only hydrometers
which are calibrated to read both the specific gravity
and the temperature, and have a table or other means
of converting the freezing point at various tempera-
tures of solution. Disregarding the temperature of
the solution when making the test may cause an error
as large as 30 degrees F. Care must be exercised to
use the correct float or table for the particular type
of anti-freeze being tested.
Fan Belt Adjustment or Replacement
A tight fan belt will cause rapid wear of the alterna-
tor and water pump bearings. A loose belt will slip
and wear excessively and will cause noise, engine
over-heating, and unsteady alternator output. A fan
belt which is cracked or frayed, or which is worn so
that it bottoms in the pulleys should be replaced. The
fan belt may be replaced by loosening the alternator
brace at alternator, slightly loosening the alternator
mounting bolts and moving alternator inward to pro-
vide maximum slack in the belt.
The alternator must be moved outward to adjust the
fan belt. After the generator brace and mounting
bolts are securely tightened, the fan belt tension
should be 45 lb. using Tensioner J-23600.
WARNING: Zfa
fan blade is bent or damaged in any
way, no attempt should be made to repair and reuse
the damaged part. A bent or damaged fan assembly
should always be replaced with a new
fal. assembly.
It is essential that fan assemblies remain in proper
balance and proper balance cannot be assured once
a fan assembly has been bent or damaged. A fan
assembly that is not in proper balance could fail and
fly apart during subsequent
we creating an ex-
tremely dangerous condition.
Radiator Thermostat Inspection and Test
A sticking radiator thermostat will prevent the cool-
ing system from functioning properly. If the thermo-
stat sticks in the open position, the engine will warm
up very slowly. If the thermostat sticks in the closed
position, the engine will overheat.
The thermostat may be removed for inspection and

REFRIGERANT COMPONENTS ALL MODELS96-39
In all instances where the indications of refrigerant
shortage continues, additional refrigerant should be
added in
l/4 lb. increments until the sight glass is
clear.
An additional charge of l/4 lb. should be ad-
ded as a reserve. In no case should the system be
overcharged.
LEAK TESTING SYSTEM
The following two methods are recommended when attempting to locate refrigerant leaks in the system.
Loss of
regrigerant is always indicative of a leak since
refrigerant is not consumed and does not wear out.
1. Open Flame Method
- This method utilizes a gas
operated torch type leak detector (J-6084). Use of
this method is recommended when checking for
leaks in confined areas. To perform test, light torch
and adjust to obtain a pale blue flame, approximately
3/8 inch in height, in burner.
Explore for leaks by moving end of search tube
around suspected area. Check bottom of connections
since Refrigerant-12 is heavier than air and will be more apparent at underside of fittings. The flame
color will turn yellow-green when a small leak is
detected. Large leaks will turn the flame blue or
purple.
WARNING:
Do not breathe fumes resdting from
burning of
refrigerant gas. These fumes az ex-
tremeiy poisonous.
2. Liquid Leak Detectors - This method utilizes a
solution which will bubble (soap solution) to signify
a gas leak. Use of this method of checking is recom-
mended for locating small leaks.
FUNCTIONAL TESTING SYSTEM
Functional testing is a measurement of the air condi-
tioner system performance to determine if discharge
air temperature, pressure in suction line, and pres-
sure in discharge line are within specific limitations.
To perform Functional test proceed as follows:
1. Remove protective caps from the compressor
adapter fittings located on compressor.
SCHRADER
ADAPTER J-5420
1II rDISCHARGE LINE
COMPRESSOR
VALVE
LOW PRESSURE
\ GAUGE\
HIGHGLR;B;URE
MANIFOLD AND
-GAUGE SET
J-5725-01
r
GAUGE LINES
(5) J-5418
9B-31
Figure 9B-40 Functional Test Set-Up