1973 OPEL MANTA belt

6A- 24 1973 OPEL SERVICE: MANUAL
on front side of timing chain to permit reinstallation
in original position.
Timing Chain Cover and Timing
Chain installation
Reinstall timing chain cover by reversing removal
procedures, pay particular attention to the following
points.
1. Clean all parts, check for wear and replace as
required. The Parts Department supplies either the two sprockets complete with chain or the chain
alone. It is not permissible to replace sprockets alone.
The chain tensioner is, with the, exception of the
tensioner body, only available as a complete unit.
2. Turn crankshaft so that key for sprocket is on top
and vertical. Assemble chain’, with camshaft
sprocket, then put chain on crankshaft sprocket al-
ready installed. Be sure paint dot
on chain is in front
so that chain moves in same direction as prior to
disassembly.
3. Make sure camshaft sprocket mark is in alignment
with mark on support and chain in parallel with
damper block.
4. To install new timing case oil seal, drive out oil
seal from the rear using a drift. Coat circumference
of oil seal sparingly with suitable sealer and press seal
in, using tool J-22924. Take care not to damage tim-
ing case. See Figure
6A-40. 5. Inspect chain tensioner for proper operation and
reusability.
6. Install timing case rubber gaskets to cylinder
block. Stick on with grease as necessary. Gaskets will
somewhat overlap with oil pan gasket.
7. Position timing cover onto guide pin in upper left
corner of cylinder block and insert centering bolt
through timing chain cover into lower right corner
of cylinder block. See Figure
6A-40A. No sealing is
required.
SA-40.4
Figure 6A-40A Installing Timing Chain Cover
INSTALLER
Figure 6A-40 Installing Timing Cover Oil Seal onProtector
It is not necessary to use crankshaft bolt to install
seal when cover is off engine. 8. Install cylinder head
After sprocket has been attached to camshaft, re-
check alignment
LO see that chain has not slipped. At
this time both No.
1 and No. 4 pistons will be at TDC
position. No. 4 piston will be in tiring position and
No. 1 piston up on exhaust stroke. To time engine to
fire on No. 1 cylinder, rotate crankshaft 360 degrees.
This will position the timing mark 180 degrees from
original alignment of camshaft sprocket and support
bracket, and will completely close No. 1 intake and
exhaust valves. Also, the timing mark on the fly-
wheel
(ball) and cylinder block (pointer) will coin-
cide. See Figure
6A-41.
Replacing Timing Cover Oil Seal
(Engine Installed)
1. Remove fan belts.
2. Remove crankshaft pulley bolt and remove pulley. 3. Insert screwdriver behind seal and rest screw-
driver on crankshaft pin. Pry out oil seal.

ENGINE MECHANICAL AND MOUNTS6A- 251, CAMSHAFT SPROCKET
2. CAMSHAFT SPROCKET SUPPORT
3. LONG DAMPER BLOCK
4. CRANKSHAFT SPROCKET
5. CHAIN AND DAMPER BLOCK
IN PARALLEL
6. CRANKSHAFT KEY
7. PAINT MARK ON FRONT
8. TIMING CHAIN
9. MARK ON CAMSHAFT
SPROCKET SUPPORT
IO. MARK ON CAMSHAFT
SPROCKET
6A-41Figure 6A-4 1 Valve Timing Marks
Removal4. Lubricate new oil seal and place on installer
J-
22924.1. Remove cylinder head.
5. Place installer J-22924 on crankshaft. Using
crankshaft bolt and washer install seal into cover. See
Figure 6A-42.2. Loosen self-locking rocker arm nuts and swing
rocker arms off valve lifters.
6. Install crankshaft pulley, bolt and washer. Torque
bolt to 72
Ib.ft.3. Remove valve lifter. Place lifters in a suitable hold-
ing fixture so that they may be reinstalled in original
position.
7. Install belts and torque to proper tension 45
lb.ft.4. Remove cover from access hole on left side andFigure 6A-42 Installing Timing Chain Cover Oil Seal
Replacing Distributor Drive Gear
On Crankshaft1. Remove fan belt.
2. Remove fuel pump. Plug end of fuel line with a
suitable stop.
3. Remove spark plug wires, distributor hold down
clamp. Remove distributor.
4. Turn crankshaft so key is on top.
5. Pry oil seal out of timing chain cover.
6. Insert a screwdriver through opening for fuel
pump and push out distributor drive gear, which has
a push tit on crankshaft, through oil seal seat in
timing cover.
7. Install new gear. Be sure key tits in
keyway. When
installing components, use new gaskets as required.
8. Install new oil seal.
9. Connect parts removed in steps 1 thru 3.
CAMSHAFT

66.321973 OPEL SERVICE MANUAL
COOLING SYSTEM
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Cooling System and Water Pump
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Checking and Filling Cooling System
. . . . . . . . . . . . . . . . . . . . . . . .Draining
andFlushingCoolingSystem. . . . . . . . . . . . . . . . . . . . . .Conditioning the Cooling System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Using and Testing Anti-Freeze Solutions
. . . . . . . . . . . . . . . . . .Fan Belt Adjustment or Replacement
. . . . . . . . . . . . . . . . . . . . . . . .Radiator Thermostat Inspection and Test
. . . . . . . . . . . . . . . .MAJOR REPAIR:
Water Pump Removal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Radiator
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Cooling System Capacities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.
68-32
6B-32
68-32
68-33
68-33
68-33
68-33
68-34
68-34
6B-35
DESCRIPTION AND OPERATION
COOLING SYSTEM AND WATER PUMPThe coiling system is of the conventional pressurized
type. A centrifugal pump arranged in timing case
serves to circulate the coolant.
When the thermostat is closed, the coolant will re-
turn to the pump via a by-pass for swift and uniform
warming up of the engine the coolant circulates
through the radiator, only when the engine has
reached normal operating temperature.
The heater system branches off the cooling system
ahead of thermostat in flow direction so that the
heater is in operation before engine has reached full
operating temperature.
MAINTENANCE AND ADJUSTMENTS
Checking and Filling Cooling SystemThe coolant level should be checked only when the
engine is cold and only enough coolant should be
added to bring the level halfway between core andtank top. It is unnecessary and undesirable to remove
the radiator cap and check the coolant level each
time the car stops at a filling station for gasoline or
oil, since the engine is usually hot at such times.
WARNING: Never remove the radiator cap quickly
when engine is HOT Sudden release of cooling
sys-
tern pressure may cause the coolant to boil and some
of it may be ejected from the radiator
filler neck,
resulting in
inl’ury to persons or damage to the car
finish.If it is necessary at any time to remove the radiator
cap when engine is hot, rotate the cap counterclock-
wise until first stop is reached. Leave cap in this
position until all pressure in cooling system has been
released, then turn cap past the first stop and remove
it.
Draining and Flushing
Cooling SystemThe cooling system should be completely drained
and the recommended coolant installed every two (2)
years.To drain the cooling system, remove radiator cap,
remove lower radiator hose from the lower tank and

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

6B- 341973 OPEL SERVICE MANUAL
test by partially draining the cooling system and dis-
connecting the water outlet housing from the ther-
mostat housing which is mounted on the right front
side of cylinder head.
The standard thermostat valve should start to open
at 189 degrees F and fully open at approximately 212
degrees F. If thermostat does not operate at specified
temperatures, it should be replaced as it cannot be
repaired.MAJOR REPAIR
WATER PUMP REPAIRSThe water pump bearing outer race is shrunk fit into
the water pump cover. For this reason the cover,
shaft bearing, and hub are not repairable.
Water Pump RemovalOpel radiators do not have a drain plug. Drain radia-
tor by first, loosening radiator cap, then remove
lower hose from lower radiator tank.
1. Drain coolant into a clean container. Remove
radiator and shroud.
2. Remove fan belt.
3. Remove fan blade and pulley on water pump shaft.
4. Disconnect inlet hose and heater hose from water
pump. Remove bolts, pump assembly and gasket
from timing chain cover.
5. Check pump shaft bearing for end play or rough-
ness in operation. If bearings are not in serviceable
condition, the assembly must be replaced.
Water Pump Installation1. Make sure the gasket surfaces on pump and timing
chain covers are clean. Install pump assembly with
new gasket. Bolts must be tightened uniformly.
Torque to 11 lb. ft.
2. Install radiator and shroud. Connect radiator hose
to pump inlet and heater hose to nipple.
3. Install fan pulley and fan blade, tighten attaching
bolts securely. Install belts and adjust for proper
tension.4. Fill cooling system and check
,for leaks at pump
and hose joints.
RADIATOR REMOVAL AND INSTALLATION
RemovalI. Loosen radiator cap, then remove lower radiator
hose and drain radiator coolant into suitable con-
tainer.
2. On vehicles with automatic transmission, unscrew
oil lines from connectors on lower radiator tank and
plug lines. On GT models with automatic transmis-
sion the lines have to be disconnected at the coupling
before removing from the tank. It is essential that no
dirt enters the oil lines. When unscrewing oil lines,
hold connectors on lower radiator tank with pliers to
avoid leakages. Ensure that no dirt enters oil cooler.
3. Remove lower attaching nut and slide radiator
upward and out of engine compartment.
Installation1. Install radiat,or into engine compartment and se-
cure lower attaching nut.
2. On vehicles with automatic transmissions, fasten
oil cooler lines to lower radiator tank. It is essential
that no dirt enters the oil lines. When tightening oil
lines, hold connectors on lower radiator tank with
pliers to avoid leakages. Ensure that no dirt enters oil
cooler. Torque to 1 I-15
lbs.ft.3. Install lower radiator hose and add collected coo-
lant.
All Opels are provided with a radiator initial fill of
an antifreeze solution containing corrosion inhibitor.
The antifreeze has either a glycol or glycerin base
and protects the engine against freezing, down to
minus 22 degrees F. (minus 30 degrees C.). Before
the start of the cold season, coolant must be checked
with a hydrometer and if necessary, brought to the
necessary specific gravity by adding anti-freeze with
a glycol or glycerin base. As the specific gravities of
all anti- freeze solutions having a glycol or glycerin
base are practically the same, the hydrometer can be
used for all these types. Because of the tolerances of
the hydrometer, or slight differences in specific
gravity, variations of plus or minus 5 degrees can be
expected. Coolant must be checked at a temperature
of plus 68 degrees F. (plus 20 degrees C.)

2. If inspection of contact points indicates excessive
burning, pitting or wear, check condenser and re-
place if necessary.
3. Inspect all connections and wires in the primary
ignition circuit. Correct any abnormal conditions
found.Carburetor1. Clean fuel strainer in fuel pump. To prevent fuel
leakage in pump, disconnect “IN” line from pump
and raise end above fuel level. The in-line fuel filter
should be replaced every 12,000 miles or every 12
months.
2. Check for freedom of choke valve operation and
clean shaft if necessary, with suitable solvent.
3. Inspect throttle cable or linkage bracket and re-
turn spring for wear. With helper depressing acceler-
ator pedal to floor, check for wide open throttle.
Adjust accelerator pedal height so wide open throttle
is obtained when pedal is within
l/2 inch from floor.
Lubricate linkage pivot points with engine oil.
Air CleanerCheck paper element every 6,000 miles and replace
every
24,ooO miles. If a vehicle is operated in dusty
territory, check condition of air cleaner element
more frequently and replace if necessary.
Fan Belt1. Inspect belt for wear, cracks or frayed points.
Replace and/or adjust as necessary. Specified ten-
sion for belt using Gauge J-23600 is 45 lbs.
Cooling System1. Inspect the radiator, water pump, cylinder head
areas and all radiator and heater hose connections
for evidence of engine coolant leaks.
2. Inspect all hoses for deterioration from gas and oil
contact. Correct as required.
Inspection should be made with engine operating at
normal temperature, cooling system completely
filled, temperature control lever fully open and nor-
mal pressure in the system. Normal pressure should
be 13.2 to 15.2 psi.
Engine Lubrication SystemInspect engine for evidence of oil leakage. Correctany abnormal condition with sealastic or new seals
and gaskets.
Battery
1. Inspect battery, battery mount and cables and
check electrolyte level. Proper level should be just
above the cell plates.
CAUTION:Do not over fill.
2. Determine the serviceability of the battery by ap-
plying the 421 Battery Test.
Positive Crankcase VentilationClean crankcase ventilator metered orifice in the in-
take manifold fitting every 6,000 miles. Also all hoses
and fittings should be inspected, cleaned and re-
placed, if necessary.
To clean, remove rubber hose from metered orifice
and apply air pressure to orifice to remove any for-
eign particles that may be trapped.
Valve Lifter AdjustmentRefer to Engine Mechanical and Mounts section for
valve lifter adjustment procedure.
Engine Tune-Up Instrument ChecksThe following instrument checks and adjustments
serve as a final check on engine condition. These
checks may discover some new problems that may
not have been obvious before. The engine is also
given its final adjustments that will assure maximum
performance, reliability, and proper emission con-
trol.
Refer to Electrical Group for checking procedures of
the following:
Cranking Voltage Check
Ignition Timing
Distributor Advance
Ignition Output
Secondary Resistance
Current Output and Voltage Setting
Idle Speed and Mixture AdjustmentsRefer to carburetor section.

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)

98.40 1973 OPEL SERVICE MANUAL
2. Interconnect manifold and gage set (J-5725-01),
gage charging lines (J-5418) and gage adapters
(J-5420) to air conditioning system as shown in Figure
9B-40.3. Place transmission in “Park” for automatics and
in neutral for manuals. Apply hand brake.
4. Turn blower switch to the “Hi” position.
5. Turn temperature switch to “Max” position.
6. Run engine at 2000 RPM for ten (10) minutes with
car doors and windows closed and the hood up. Place
a high volume industrial type fan in front of radiator
if head pressure should exceed 250 psi and also at
high ambients to bring the pressures to within the
limits specified in the Functional Charts in Division
V.In the case of the Opel 1900 and the Manta, a ther-
mometer should be placed in a position to read the
temperature of the air discharging from the right-
hand A/C outlet. In case of the GT, a thermometer
should be placed in a position to read the tempera-
ture of the air discharging from the left-rear A/C
outlet.
HEATER-AIR CONDITIONER REFRIGERANT
CIRCUIT TROUBLE DIAGNOSIS GUIDE
Insufficient Cooling (Check Air Flow)
Normal Air Flow (Inspect system for visual defects.
Run functional tests.)
Discharge Air
- Normal Temp Check for air leaks
through dash, car body, windows, or from heater or
ventilators.
Discharge Air
- High Temp Check sight glass for
foaming and compressor clutch for engagement.
No Compressor Clutch Engagement Check connec-
tions at clutch switch, harness connectors, and check
clutch switch.
No Foaming Compare evaporator pressure to that
on functional test table.
Foaming System is probably low on refrigerant.
Check for leaks, repair, evacuate, and charge. If
foaming still occurs, check for restriction in refriger-
ant lines between condenser and receiver dehydrator.
Evaporator Pressure Normal Compare head pres-
sure to pressure on functional test table.
Evaporator Pressure Low Ice may be forming on
evaporator. Low volume of air discharging at A/C
outlet after system has been running above idle con-dition
,for approximately 15-30 min.utes. Discharging
air gradually elevating in temperature. Check expan-
sion valve. If valve isn’t permitting flow of liquid,
this will be indicated by a warm pipe out of the
evaporator. This may be caused by: 1) Clogged or
Plugged inlet screen in the expansion valve; 2)
Broken capillary line; or 3) Discharged temperature
bulb. If the valve is okay, the pipe out of the evapora-
tor will be cold.
Evaporator Pressure High Check the expansion
valve to determine if themobulb is making good con-
tact and is properly insulated. Operate engine at 2000
RPM with maximum air conditioning setting. If
evaporator pressure remains high, feel suction line.
If line feels frosty or extremely
(cold with relative
high ambient conditions, then partially cover the
condenser to obtain head pressures from 265 psi to
280 psi maximum. If evaporator pressure rises above
30 psi, change the expansion valve.
Also, check if compressor may be the cause due to
some internal or external mechanical trouble which
prevents reduction of pressure. Check for external
troubles, slipping belt, bad clutch and/or pulley, or
improper clutch engagement, before investigating
the compressor internally.
Head Pressure High Check for the following: Con-
denser air flow low, air in system, excessive refriger-
ant in system, restriction in condenser.Head.PressureLowRestriction in flow of refrigerant
to evaporator, or expansion valve plugged or defec-
tive.
Low Air Flow (Check blower operation and
evaporator. Check operation of controls.)
Ice BIocking Evaporator Run functional test. If
evaporator pressure is low, ice may form on evapora-
tor and reduce air flow.
Evaporator Pressure Low Ice may be forming on
evaporator. Low volume of air discharging at A/C
outlet after system has been running above idle con-
dition for approximately 15-30 minutes. Discharging
air gradually elevating in temperature. Check expan-
sion valve. If valve isn’t permitting flow of liquid,
this will be indicated by a warm pipe out of the
evaporator. This may be caused by: 1) Clogged or
plugged inlet screen in the expansion valve; 2)
Broken capillary line, or 3) Discharged temperature
bulb. If the valve is okay, the pipe out of the evapora-
tor will be cold.BlowerNot OperatingCheck for the following: Fuse
blown, blower switch defective, wire broken or loose
connection, poor ground connection, or blower mo-
tor defective.