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Accessory Drive Belts
Low Engine Temperature
Symptom (and Action)
Accessory Drive Belts
Coolant Reserve System
Engine Block Heater
Engine Coolant Temperature Gauge
Fluid Fan Drive
Pressure Testing Radiator Cap
Pressure Testing Cooling System
Radiator Pressure Cap
Transmission Oil Coolers
Testing Coolant System
(1) Standard System
(a) Without Air Conditioning
(b) With Air Conditioning
(2) Maximum Engine Cooling System
Both cooling systems consist of a tube and spacer type radiator, 14-18 PSI (97-124 kPa) radiator pressure cap, centrifugal water pump, 192-199�F (88-93�C) thermostat, a five blade fan (with Fluid Fan Drive) and a coolant reserve system. All applications have a fan shroud, automatic trans mission oil cooler and air seals.
The Maximum Engine Cooling system consists of a greater heat-transfer ability radiator, oil-to-air transmission oil cooler in addition to oil-to-water.
A Coolant Reserve System is used on all models to provide reserve volume for normal losses plus adequate volume expansion for the coolant when hot. The reserve tank stores coolant and provides a convenient method for visually check ing level and adding coolant when needed with out removing the radiator cap.
All Chrysler-built rear wheel drive vehicles provide cooling system corrosion protection with antifreeze to -35�F (-37�C) at time of manufacture. It is recommended that the coolant be changed initially after 3 years or 52,500 miles, (84,000 km,) and then every 2 years or 30,000 miles (48,280 km) to insure adequate protection (also, add soluble oil, 1/4 of 1% by volume on change). All vehicles must be protected at all times by coolant concentration of 50% minimum and 65% maximum (Glycol) for boil protection in warm climates and freeze protection in cold climates.
Mopar, Prestone II, PEAK, or antifreeze containing Alugard 340-2 corrosion inhibiters required with materials used in the cooling system.
CAUTION: AVOID MIXING BRANDS.
Most models are equipped with air seals. These seals are designed to direct fresh air through the radiator and to prevent hot recirculating air from going through the radiator a second time. These seals are required to prevent overheating under some operating conditions, excessive air conditioning head pressures, poor air conditioning performance and excessive temperature of several under hood components which affects their endurance life. It is therefore important to maintain these seals in their proper attachment. When seals are removed for other reasons, they should be replaced in proper position. Seals should be so positioned that they do not touch exhaust manifold.
PRELIMINARY ENGINE COOLING SYSTEM OVERHEAT DIAGNOSIS
Establish what �driving� conditions cause the cooling system complaint, such as:
1. AFTER PROLONGED IDLE, HIGH AMBIENTS, A/C SYSTEM ON, SLOW TRAFFIC, TRAFFIC JAMS, AFTER HIGH SPEED:
Consider idle duration, see owners manual: �Starting Procedure� section for engine idle duration. Driving techniques that avoid overheating in slow traffic and in traffic jams.
(a) Idle with A/C off as much as possible.
(b) Increase engine speed temporarily for more air flow and coolant flow.
2. TRAILER TOWING:
Consult owner�s manual�Trailer Towing.
3. AIR CONDITIONING: ADD-ON or AFTER MARKET:
A maximum cooling package should have been ordered with the vehicle if add-on or after market A/C is involved. If not, maximum cooling components should be installed for the model involved per manufacturer�s specifications.
Further diagnostic checks should not be required.
4. RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been performed on the vehicle that may affect the cooling system such as engine adjustment (wrong timing), brakes (possibly dragging), changed parts (possibly wrong), recored radiator or cooling system refilling (possibly over-filled or trapped air).
If investigation reveals none of the above as cause for overheating complaint refer to the following symptoms chart.
SYMPTOM and ACTION
(See Preliminary Chart FIRST)
Glowing Engine Warning Light Normal with temporary operation with heavy load, towing a light trailer, high or High Gage Indication�Without outdoor temperatures, and/or on a steep grade.
Coolant Loss Consult �Engine Overheating Diagnosis� if none of the following conditions exist.
�Gage or Sending Unit Faulty. See Group 8 Electrical.
�Correct Anti-Freeze concentration.
�Recently Refilled, see next item.
Coolant Loss Improper refilling procedures can result in trapped air in the system. Subsequent operation of the pressure cap and coolant recovery system will deaereate the coolant. A low coolant level will then result.
Add coolant. If condition persists see Diagnosis Chart
Hot Car (Not Engine) Check heat shielding, exhaust system, emission controls, carburetion, mis-
Heat Damage firing.
Hot Carpet, Seat, Trunk
Hot Catalytic Converter
Smoke, Burnt Odor
Hot Engine A moderate amount of sound of heating metal can be expected with any car.
Crackling Sounds However, a crackling sound from the thermostat housing, a hot smell and/or
Hot Smell severe local hot spots on an engine can indicate blocked coolant passages.
Severe Local Hot Spots Inspect for water passages not drilled out on a new engine, core sand plugging, a cracked block or head, or a blown head gasket. Usually accompanied with coolant loss.
Cold Spots on Radiator
No (or low) Heater Output
Coolant Recovery Bottle
�Coolant NOT Returning
Warm up engine, then turn engine off. Feel radiator. It should be hot across the top and warm along the bottom with an even temperature drop from top to bottom. If cold spots exist, the radiator may be plugged. Consult radiator section.
On NC equipped vehicles it may be necessary to operate the vehicle without the fan and shroud in order to feel the radiator surface.
Repair source of obvious leaks such as physically damaged or mis-installed part, loose parts, etc. See Diagnostic Chart if leak is not easily detected.
Check heater air damper linkage operation, water pump output (see Water Pump) and consult the Diagnostic Charts before changing the thermostat.
Coolant color is not necessarily an indication of adequate temperature or corro sion protection.
Some oily discoloration of the coolant recovery system bottle will occur due to the production use of soluble oil (also called water pump lubricant) which has
been added for corrosion protection.
Level changes are to be expected as coolant volume changes with engine temperature. If the level in the bottle is between the Maximum and Minimum marks at normal engine operating temperature, the level will return to within that range after operation at elevated temperatures.
Coolant will not return to the radiator if the radiator cap vent valve does not function, if an air leak destroys vacuum, or if the overflow passage is blocked or restricted.
Inspect all portions of the overflow passage, cap, filler neck nipple, hose, and passages within the bottle for vacuum leak only. Coolant return failure will be evi dent by a low level in the radiator. Bottle level should increase with each heat-up.
�Overflowing (Coolant loss to An overflowing coolant recovery bottle can indicate a pressure leak. Either at the Ground) cylinder head gasket or as an air leak into the inlet (suction) side of the water
pump, or simple overfilling of the coolant recovery bottle, and from overheating.
Overheating at low speed driving, idling and/or city traffic is usually primarily due to the fan system. Consult the Engine Overheating Diagnosis Chart.
Overheating during high speed driving is usually primarily due to coolant flow deficiencies, or air flow loss to the radiator. See �Engine Overheating Diagnosis� chart.
Low Speed Overheating
High Speed Overheating
ACCESSORY DRIVE BELTS
Proper Belt Tension
Satisfactory performance of belt driven acces sories depends on maintenance of proper belt tension. Either the Borrough�s gauge or torque methods can be used. The preferred method is to use the Borrough�s gauge since it will provide more accurate results.
Borrough�s Gauge Method
The belts may be adjusted by measuring the tension of the belts with a Borrough�s gauge. Check the tension of the belt in the middle of the span between the two pulleys (arrows Fig.1) with Tool C-4162. The correct tension is 120 lbs. (530 N) on a new belt and 70 lbs. (310 N) on a used belt. A belt is considered used after 15 minutes of running time. Belt tension must be read on the gauge after tension has been ap plied to the accessory and mounting bolts tightened to the specified torque.
Some belts may be adjusted to the specified tension by use of a torque wrench. Alternator belts are adjusted by using Tool C-3841A. The tool should be hooked at the heavily ribbed section of the alternator to prevent damage. Other accessory belts may be tightened with a torque wrench using the square holes in the brackets.
To tighten belts by the torque method, loosen all adjustment bolts and apply specified torque to the accessory (see Specifications). Initial orientation of the torque wrench should be approximately vertical to obtain proper tension unless otherwise specified. Tighten all adjustment bolts while torque is applied to the accessory. Use an extension where it is required to obtain clearance for the torque wrench.
CAUTION: Do not run engine when making belt adjustment.
Prior to tensioning any accessory, all bolts for sliding or pivoting adjustment for that accessory should be loosened. Bolts should be tightened to proper torque while tension is applied to the accessory. It may be necessary to repeat this procedure several times to obtain the proper belt tension.
On power steering pumps, tensioning is accomplished by inserting a 1/2 inch drive torque wrench into the square hole and rotating until proper belt tension is obtained.
CAUTION: To prevent damage to power steering pump, do not pry against pump.
Alternator belts may be tensioned by carefully placing a bar between the alternator brackets and alternator and applying tension on the alternator housing.
CAUTION: When applying tension with a bar, special precautions must be taken to prevent damage to the alternator. The bar should contact the center of the alternator housing at the stator support.
Air pumps are tensioned by pulling on the pump by hand.
CAUTION: To prevent damage to the air pump, do not use a bar to tension the belt.
Air conditioning compressor belts are tensioned at the alternator.
Radiators are equipped with a 14-18 psi (97-124 kPa) pressure cap as standard equipment on all models.
The system can operate at higher than atmospheric pressure which raises the coolant boiling point allowing increased radiator cooling capacity. The cap contains a pressure relief spring loaded valve that opens when the pressure exceeds 14-18 psi (89-124 kPa) (Fig. 2). There is also a vent valve in the center of the cap that allows a small flow through the cap when below boiling temperature but is closed by an increase in flow as the boiling point is reached.
This valve also opens when coolant is cooling and contracting allowing coolant to return to radiator from coolant reserve system tank by vacuum through connecting hose. If valve is stuck shut the radiator hose will be observed collapsed on cool down. Clean the vent valve (Fig. 2) to ensure proper sealing when boil point is reached.
There is also a gasket in the cap to seal to the top of the filler neck so that vacuum can be maintained for drawing coolant back into the radiator from the coolant reserve tank.
WARNING: THE WARNING WORDS �DO NOT OPEN HOT� ON THE RADIATOR PRESSURE CAP IS A SAFETY PRECAUTION. WHEN HOT, PRESSURE BUILDS UP IN COOLING SYSTEM. TO PREVENT SCALDING OR INJURY, THE RADIATOR CAP SHOULD NOT BE REMOVED WHILE THE SYSTEM IS HOT AND/OR UNDER PRESSURE.
There is no need to remove the radiator cap at any time except for the following purposes:
(1) Check antifreeze freeze point.
(2) Add antifreeze to lower freeze point.
(3) Refill system with new antifreeze.
(4) Conducting service procedures.
(5) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY, WAIT 15 MINUTES BEFORE REMOVING CAP, THEN PLACE A RAG OVER THE CAP AND TURN IT TO THE FIRST STOP. ALLOW PRESSURE TO ESCAPE THROUGH THE OVERFLOW TUBE AND WHEN THE SYSTEM STABILIZES (AND WATER STOPS FLOWING TO RESERVE BOTTLE) PUSH DOWN AND RE MOVE THE CAP COMPLETELY. SQUEEZING THE RADIATOR INLET HOSE WITH A RAG (TO CHECK PRESSURE) BEFORE AND AFTER TURNING TO THE FIRST STOP IS RECOMMENDED.
All cars are equipped with this system which consists of a translucent plastic reserve tank with a connecting tube to the radiator filler neck and a special pressure cap. The plastic tank has a filler opening and a cap and an overflow open to the atmosphere, With this system the radiator is normally completely full. When coolant in the engine expands and is forced out of the radiator, it overflows into the reserve tank. When the engine cools down the coolant contracts and vacuum draws coolant from the reserve tank back into the radiator thus keeping it full.
Testing Coolant Reserve System
With coolant in the reserve tank at the proper level and radiator cap installed, open the radiator drain cock. Coolant should be drawn from the reserve tank into the radiator. Do not leave drain cock open to drain reserve tank and allow air into system. If test does not draw coolant from the reserve tank, check for plugged coolant reserve tank nipple, kinked overflow hose and for leaks at the radiator filler neck and overflow nipple, radiator cap and reserve tank tube.
It may be necessary to pressure test the radiator cap and cooling system to locate a leak. The upper gasket seal can be checked by removing the hose at the filler neck. Pump air into the cooling system. The top seal in the pressure cap should relieve at 10 to 18 psig (16-124 kPa) and hold at 8 psig (55 kPa) minimum.
Checking Coolant Level
Do not remove radiator cap for routine coolant level inspection.
The coolant reserve system provides a quick visual method for determining that the coolant level is adequate. Simply observe, with the engine idling and warmed up to normal operating temperature, that the level of the coolant in the plastic reserve tank is between the minimum and maximum marks. When additional coolant is needed to maintain this level it should be added to the plastic reserve tank. Use concentration of 50% minimum and 65% maximum ethylene glycol type antifreeze such as Mopar, Prestone II, Peak or those formulated with Alugard 340-2 and water. Antifreeze should be provided for and checked in both the radiator and the reserve tank.
Add antifreeze coolant (not less than 50% concentration, described in �Checking Coolant Level�) to the radiator until completely full. Start engine and run until the upper radiator hose feels hot. Stop engine and add more coolant, if necessary, to completely fill radiator. Add antifreeze coolant to the reserve tank up to a level between the max. and mm. marks. To maintain this level, it may be necessary to add coolant to the reserve tank after two or three warm-ups because air is generally trapped in the cooling system as the system is filled. Be sure that the heater valve is in the wide-open position when refilling the cooling system. Antifreeze protection should be checked after mixing.
PRESSURE TESTING RADIATOR CAPS
Dip the pressure cap in water and apply cap to end of tool. Working the plunger, as shown in (Fig. 4) bring the pressure to 15 pounds (104 kPa) on the gauge. If the pressure cap fails to hold pressure of at least 14 pounds (97 kPa), clean any deposits on the sealing surface of the vent valve and retest before replacing.
CAUTION: Tool C-4080 is very sensitive to small air leaks which will not cause cooling system problems. A pressure cap that does not have a history of coolant loss should not be replaced just because it leaks slowly when tested with this tool. Add water to the tool, turn tool upside down and recheck pressure cap to confirm that cap is bad.
Replace cap if it fails to hold pressure. If the pressure cap tests properly while positioned on Tool C-4080, but will not hold pressure or vacuum when positioned on the radiator, inspect the radiator filler neck for irregularities that may prevent the cap from sealing properly.
The vent valve at the bottom of the cap should hang freely. If the rubber gasket has swollen and prevents the valve from hanging loosely, replace the cap. Hold a cleaned cap in hand upside down. If any light can be seen between vent valve and rubber gasket replace cap. Do not use a replacement cap without this vent valve that hangs freely.
Replacement cap must be of the type designed for coolant reserve system with a completely sealed diaphragm, spring and a rubber gasket to seal filler neck. This is in order to assure coolant return to radiator.
PRESSURE TESTING COOLING SYSTEM
(1) With engine not running, wipe the radiator filler neck sealing seat clean. The radiator should be full.
(2) Attach the Tester Tool C-4080 to the radiator, as shown in (Fig. 5) and apply 15 pounds (104 kPa) pressure. If the pressure drops more than 2 psi in 2 minutes inspect all points for external leaks.
(3) If there are no external leaks, after the gauge dial shows a drop in pressure, detach the tester, start engine and run the engine to operating temperature in order to open the thermostat and allow the coolant to expand. Reattach the tester and pump to 7 lbs. (48 kPa) pressure while the engine is running. Race the engine, and if the needle on the dial fluctuates it indicates a combustion leak, usually a head gasket.
WARNING: PRESSURE BUILDS UP FAST. ANY EXCESSIVE AMOUNT OF PRESSURE BUILT UP BY CONTINUOUS ENGINE OPERATION MUST BE RELEASED TO A SAFE PRESSURE POINT. NEVER PERMIT PRESSURE TO EXCEED 20 LBS. (138 kPa).
(4) Do not remove spark plug wires from plugs or by any other means short out cylinders if exhaust system is equipped with catalytic converter.
(5) If the needle on the dial does not fluctuate, race the engine a few times and if an abnormal amount of �coolant or steam� emits from the exhaust system at the tail pipe, it may indicate a leak that can be a faulty head gasket, cracked engine block, or the cylinder head near the exhaust ports.
(6) If the above pressure test of the cooling system holds without fluctuation, then there is no leak, however, there may be internal leaks which can be determined by removing the oil dipstick and if water globules appear intermixed with the oil it will indicate a serious internal leak in the engine. If there is an internal leak, the engine must be disassembled, the leak located and necessary new parts installed.
For Removal, Installation and Testing procedures of the water temperature sending and receiving units, refer to �Electrical� Group 8 �Gauges�.
Description and Operation
The engine cooling thermostat is a wax pellet driven, reverse poppet, choke type. It is designed to provide the fastest warm-up possible by preventing leakage through it, and to guarantee a minimum engine operating temperature of 88�C to 93�C (192�F to 199�F). It also automatically reaches wide open so it does not restrict flow to the radiator as the temperature of the coolant rises in hot weather by around 104�C (220�F). Above this temperature the coolant temperature is controlled by the radiator, fan and ambient temperature, not the thermostat. The thermostat (Fig. 6), is located on the top of the intake manifold.
To determine the cause of engine overheating or slow warm-up, refer to Service Diagnosis Charts. �Thermostat Testing Procedure.� The thermostat should be tested for operation with it installed in the engine. The thermostat is faulty only if it fails to stabilize within the temperature range indicated in the testing procedure.
The specified thermostat should always be used to control engine temperature, exhaust emissions, and heater/defroster performance to acceptable levels. The use of a lower setting thermostat will not relieve overheating and will result in low heater/defroster performance.
(1) Drain cooling system down to thermostat level or below.
(2) Remove thermostat housing bolts and housing.
(3) Remove thermostat, discard gasket and clean both gasket sealing surfaces.
(1) Using a new gasket (dipped in clean water), or new bead of rubber sealer, position thermostat so pellet end is toward engine. Attach with bolts through housing. Check to be sure no water flow will bypass thermostat.
(2) Tighten bolts to 200 in. lbs. (23 N�m) on 318 engine.
(3) Refill cooling system to completely fill radiator. See Refilling System.
Coolant Controlled Exhaust Gas Recirculation (CCEGR) Valve
Refer to Group 25 of this Service Manual for complete description, diagnosis and service procedure.
Coolant Controlled Engine Vacuum Switch (CCEVS)
Refer to group 25 of the service manual for diagnosis and service procedure.
The hoses are removed using a screwdriver and installed using a torque wrench to tighten band clamps.
A hardened, cracked, swollen or restricted hose should be replaced. Do not damage fittings when loosening hose.
The reinforcement spring inside the lower hose is necessary to prevent collapsing of the hose due to water pump suction at medium or high engine speeds. If this spring is misplaced in hose, it should be repositioned. If this spring is deformed, hose and spring must be replaced.
CAUTION: Do not overtighten to prevent hose and clamp damage. Tighten using torque wrench to 35 in. lbs. (4 N�m).
Radiator hoses should be routed without any kinks and indexed as original. The use of flexible hoses is not recommended. Use only molded hoses.
(1) Drain cooling system. Move temperature selector for heater to �full on.� Without removing pressure cap and with system not under pressure, open draincock. When coolant reserve tank is empty, remove pressure cap to hasten completion of draining.
(2) On vehicles with automatic transmission, disconnect oil cooler hose at radiator bottom tank
(3) Remove upper and lower radiator hose clamps and disconnect coolant reserve tank tube from the radiator filler neck nipple. Remove hoses from the radiator. Do not use a screwdriver to pry off hoses, because the hose fittings may be damaged.
(4) Remove shroud attaching screws, separate from radiator, position shroud rearward on engine for maximum clearance to radiator.
(5) Loosen radiator attaching screws at the bottom. Remove radiator attaching screws at the top.
(6) Radiator can now be lifted free from engine compartment. Care should be taken not to damage radiator cooling fins or water tubes during removal. Fan damage must also be avoided.
(1) Position shroud rearward on fan.
(2) Slide radiator down into position behind radiator support and locate lower radiator mounting holes on the loosened bottom attaching screws. Install upper attaching screws and tighten all attaching screws. Torque to 95 In. Lbs. (11N�m).
(3) Install shroud, connect radiator hoses, coolant reserve hoses, and transmission oil cooler hose. Open heater valve.
(4) Install radiator hose clamp and torque to 35 In. Lbs. (4 N�m).
(5) Install automatic transmission hose clamps and torque to 15 In. Lbs. (2 N�m).
(6) Install shroud attaching screws and torque to 105 In. Lbs. (12 N�m).
(7) Fill cooling system through filler neck with water and antifreeze. Fill to the top of the filler neck. Also, fill the coolant reserve tank (bottle) to �Max.� level. After warm-up, recheck coolant level. See �Refilling System.�
(1) Drain cooling system and refill with clean water and a reliable cooling system cleaner.
(2) Operate engine according to directions on cleaner label.
(3) After cleaning operation, flush entire cooling system with tap water until water runs clear.
(4) Regardless of climate, the cooling system should be refilled with sufficient permanent type antifreeze for -35�F. (-37�C) protection, to ensure adequate corrosion, boil and freeze protection (add soluble oil).
(5) If vehicle is equipped with air conditioning the cooling system must contain antifreeze all year round. This is necessary because in the reheat-cycle system used on all vehicles, cold refrigerated air passes through the heater core. Anti freeze is necessary to prevent the heater core from freezing (which can cause heater leaks) in hot weather when the air conditioner is being used.
REVERSE FLUSHING THE COOLING SYSTEM
Reverse flushing of the cooling system is the forcing of water through the cooling system, using air pressure in a direction opposite to that of the normal flow of water.
Flushing Cylinder Block
(1) Drain radiator and remove hoses at radiator.
(2) Remove thermostat and reinstall thermo stat housing.
(3) Install Tool C-3514, or other suitable flushing gun to radiator inlet hose (attached to thermostat housing).
(4) Connect water hose of gun to a pressure water source and air hose of gun to a pressure air source.
(5) Turn on water, and when cylinder block is filled, turn on air (up to 20 psi) (138 kPa) in short blasts.
(6) Allow cylinder block to fill between blasts of air.
(7) Continue this procedure until water runs clean. Reinstall; thermostat using a new housing gasket dipped in water.
(8) Fill cooling system. See Refilling System.
Reverse Flushing Radiator
(1) Drain cooling system and remove hoses from engine.
(2) Install Tool C-3514, or other suitable flushing gun in radiator lower outlet.
(3) Fill radiator and turn on air in short blasts.
CAUTION: Internal radiator pressure must not exceed 20 psi (138 kPa) as damage to radiator may result.
(4) Continue this procedure until water runs clean.
It is a good policy to reverse flush heater core any time the radiator is reverse flushed.
(5) Fill cooling system. See Refilling System.
TRANSMISSION OIL COOLERS
Automatic transmission oil cooling is accomplished by a cooler located in the bottom tank of the radiator and cooled by engine coolant (Fig. 7). Some Models are equipped with an air-cooled auxiliary oil cooler mounted in front of the radiator, and connected in series with the bottom tank transmission oil cooler (Fig. 8). Oil flow from the transmission should go through the bot tom radiator tank cooler then the auxiliary oil cooler, and then return to transmission.
Testing Oil Cooler for Leaks
In case of a leak in the bottom tank cooler, engine coolant may become mixed with transmission fluid, or transmission fluid may enter the engine cooling system. Both cooling system and transmission should be drained and inspected in the event cooler is leaking.
Note that transmission oil is red and a leak will show a gain in coolant.
Auxiliary Oil Cooler Leak Test
A leak in the auxiliary oil cooler should be detected by observing transmission fluid on the surface of the cooler or by applying air pressure up to 30 psi (207 kPa).
Bottom Tank Cooler Leak Test
(1) Disconnect both oil cooler hose sections at lower tank.
(2) Connect a pressure gauge to one cooler connection and a shut off valve to the other. Close the valve.
(3) Connect a source of air pressure to the valve.
(4) Coat all fittings and hose connections with soap solution.
(5) Open the test valve and apply (up to 100 psi) (689 kPa) air pressure. Soap bubbles will identify any fitting joint leaks. Repair any leaks at fittings or hose connections.
(6) Close the valve. Gauge reading will then drop if cooler is leaking.
Repairing Leaks in Auxiliary Oil Cooler
The transmission auxiliary oil cooler is made entirely of aluminum except end plates and mounts are steel and can be repaired by a local reliable radiator service having the equipment for alumibrazing or heliarc.
Replacing Oil Cooler in Bottom Tank
(1) Remove radiator from vehicle (see �Radiator Removal"), and remove side straps from bottom tank only.
(2) Remove radiator bottom tank.
(3) Melt the soft solder holding the cooler to the tank.
(4) Remove the stamped retainer nuts holding the cooler fittings to the bottom tank and remove the cooler.
(5) Install a new cooler in bottom tank and install the stamped retainer nuts on oil cooler fittings. Do not use a larger diameter oil cooler than original in radiator so as to prevent obstruction to coolant flow through the radiator tubes.
(6) Use soft solder to secure the cooler in the tank.
(7) Attach bottom tank to radiator using soft solder and replace side straps.
(8) Install radiator as described in Paragraph �Radiator�.
(9) Fill cooling system and test for leaks.
(10) Should it become necessary to replace oil cooler lines avoid the use of rubber or copper substitutes to avoid line failure and oil degradation.
If the transmission operates properly after re pairing the leak, drain the transmission and torque converter while hot, remove the transmission oil pan and inspect for sludge, rust, dirty or plugged inlet filter. If none of these conditions are found, reconditioning may not be necessary. Reassemble, using transmission fluid of the type labeled DEXRON II.
There are no repairs to be made to the fan. If the fan is bent or damaged, it must be replaced.
To check fan for being bent or damaged:
(1) Lay fan on a flat surface with leading edge facing down. Replace fan if there is more than .090 inch (2.0 mm) clearance between the blade tip touching the flat surface and the opposite blade. Rocking motion of opposite blades should not exceed .090 inch (2.0 mm). NEVER BEND OR STRAIGHTEN FAN.
Replacement fan, fan spacer, or fluid fan drive should always be with only the recommended part, for strength, performance and to insure durability.
(2) Inspect fan assembly and replace if there is evidence of cracks, bends, loose rivets or broken welds.
CAUTION: Do not stand in line or near fan when accelerating engine speed.
(1) Remove shroud attaching screws, separate shroud from radiator, position shroud rearward on engine. Fan attaching screws can now be removed.
(2) Disconnect fusible link (safety) in engine compartment and partially drain coolant.
(3) Remove upper radiator hose from radiator.
(4) On models equipped with fluid fan drive, remove fan drive attaching screws. The fan and fluid fan drive are removed as a unit.
(1) Reinstall spacer and fan; on engines with fluid fan drive, no spacer is used.
(2) Install fan attaching bolts and tighten to 200 in. lbs. (23 N�m).
(3) Install belt, fan, and shroud. Adjust fan belt as outlined in �Belt Tension Specifications.�
FLUID FAN DRIVE
CAUTION: To prevent silicone fluid from draining into fan drive bearing and losing the lubricant, do not place drive unit on work bench with rear of shaft pointing downward. See Figure 13.
A fluid fan drive should be replaced if there is indication of a fluid leak, if noise or roughness is detected when turning unit by hand, if unit cannot be turned by hand, or if leading edge of fan can be moved more than 1/4� (6 mm) front to rear.
Thermal Control Drive
The Thermal Control Drive (Figs. 9 and 10) is essentially a silicone fluid filled coupling connecting the fan to the fan pulley. The unit allows fan to be driven in normal manner at low speeds
while limiting the top speed of the fan to a pre determined level at higher engine speeds. A thermostatic spring is on the front face. This thermostat senses temperature from the radiator discharge air and engages the drive for higher fan speed if temperature from the radiator rises above a certain point.
Testing Thermal Control Drive
In case of engine overheating, the thermal control drive can be checked for operation by observing movement of the spring and shaft. To check, lift end of thermostatic coil from slot (Fig. 11) and rotate counterclockwise until a stop is felt. Gap between end of coil and clip on housing should be approximately 1/2 inch (12 mm) (Fig. 12). Replace drive unit if shaft does not rotate with coil.
After testing, reinstall end of coil in slot.
Procedure for Performance Testing - Viscous Fan Clutch
Prior to going through a checking procedure on the viscous fan clutch, for an overheating complaint, the other cooling system items should be checked as directed by Service Diagnosis.
The viscous fan clutch with a multi-bladed fan is a temperature sensitive and torque limiting device. The bi-metal coil on the face of the viscous fan clutch senses the temperature of the air passing through the radiator core. Until engine cooling is called for, the fan will idle along at a reduced speed despite elevated engine speed. Only when sufficient heat is present in the radiator core, to cause a reaction of the bi-metal sensing coil, will the viscous fan clutch engage and come up in speed to perform the necessary engine cooling. All viscous fan clutches are calibrated to operate to pre-set maximum speed limitations as determined by the torque generated by the fan used with it. Once that maximum fan speed has been reached the fan will not turn faster despite increased engine speed. When the necessary engine cooling has been accomplished and the level of heat passing through the radiator core has been reduced, the bi-metal coil again reacts and the fan speed reduces to the previous disengaged condition.
To check the function of the viscous fan clutch on a vehicle with an overheating complaint, it is necessary to follow these steps:
(1) Prepare car for test as follows: (Ambient temperature above 70�F (21�C).
(a) Drill a 1/8� (3 mm) diameter hole in top center of shroud between leading edge of fan and radiator core face. Insert a dial thermometer (Tool C-4347, 0-220�F 8� (203 mm) stem or equivalent) through shroud. Take Caution that fan clearance is adequate.
(b) Install Engine Tachometer and engine ignition timing light, used as strobe light.
(c) Block Air Conditioning condenser with a plastic sheet-insert between vertical hood lock support and the air conditioning condenser. On non air conditioned models, block radiator air flow. Tape sheet at top to yoke and take care to insure good seal.
(2) Air Conditioning is to be turned off to prevent high compressor head pressures. Ambient temperature should be 70 �F (21�C) or more. With Air Conditioning on, high head pressure may blow Air Conditioning head gasket.
(3) Start engine and run test at 2400 rpm engine speed, with engine ignition timing light aimed at fan blade as strobe light.
(4) Within ten (10) minutes the air temperature measured on Dial Thermometer should reach maximum of 190�F (88�C). Satisfactory operation of drive requires that the fan drive engage before or at 190�F (88�C). Engagement is distinguish able by an increase in fan roar. Timing light will also show increase in speed of fan.
(5) When dial thermometer temperature reaches 190�F (88�C) remove plastic sheet from blocking air conditioning condenser or radiator. Satisfactory operation of drive requires temperature to drop 20�F (6.7�C) or more. Satisfactory operation of drive also requires that drive be heard to disengage. Timing light will show disengagement and a slowing down of the fan drive.
(6) Do not allow thermometer temperature above 200�F (93�C).
Since there is no method available to service the viscous fan drive, any unit determined to be defective must be replaced.
Water Pump Flow Check
A quick test to see if the heater warms properly will tell you whether or not the pump is working. However, if the heater works and you still have an overheating problem there may be internal restrictions in radiator, head or engine block.
The water pump is serviced only as an assembly. When replacing the pump - care should be taken to use correct pump since pump impeller must be cornpatible with the drive ratio provided by pulley sys tem or overheating and or heater core failure will result. See Specifications and Parts listings for correct application.
The water pump on all models can be replaced with out discharging the air conditioning system.
A water pump bearing or shaft failure could damage the fan. In some cases, this damage might be difficult to detect. If the water pump, as it is failing, causes the fan to vibrate, the fan may be stressed to an unsafe limit which would tend to cause early fan failure. Therefore, when replacing a water pump because of a bearing or shaft failure, replace the engine fan at the same time to prevent possible blade separation.
Water Pump Removal - (318 Engine)
(1) Drain cooling system. Disconnect battery.
(2) Loosen fan shroud.
(3) Disconnect top radiator hose at radiator and tie back over engine.
(4) Remove alternator belt and power steering belt if so equipped.
(5) Remove fan, fan shroud, fan spacer, fluid fan drive and water pump pulley.
CAUTION: When Fluid Fan Drive has been removed, place assembly on bench as shown in Fig. 13, to prevent silicone fluid from draining into fan drive bearing and losing the lubricant.
(6) Disconnect alternator mounting brackets to clear water pump and set alternator aside. The air compressor may be set aside or blocked up.
(7) Disconnect power steering pump if so equipped and set aside.
(8) Disconnect lower radiator hose and bypass hose at the water pump.
(9) Remove water pump. Discard old gasket and clean mating surfaces.
Water Pump Installation - (318 Engine)
(1) Install water pump using a new gasket. Tighten pump bolts to 30 ft. lbs. (41 Nm). Rotate pump to be sure it turns freely.
(2) Connect lower radiator hose and bypass hose, (install new bypass hose if required).
(3) Assemble power steering pump and bracket.
(4) Assemble air compressor, alternator and related brackets.
(5) Assemble fan, fan shroud, fan spacer, fluid fan drive and water pump pulley.
(6) Install and tighten power steering and alternator belts. Tighten to specifications.
(7) Fill cooling system. See refilling system.
ENGINE BLOCK HEATER
Description and Operation
On all models an engine block heater is available as an optional accessory. The heater, operated by ordinary house current (110 Volt A.C.) through a power cord and connector behind the radiator grille, provides easier engine starting and faster warm-up when vehicle is operated in areas having extremely low temperatures. The heater is mounted in a core hole (in place of a core hole plug) in the engine block, with the heating element immersed in coolant.
On V-8 engines, a heater is mounted on each side of the engine in the core holes below the exhaust manifolds. (Fig. 14).
The power cord must be secured in its retainer clips, and not positioned so it could contact linkages or exhaust manifolds and become damaged.
If unit does not operate, trouble can be in either the power cord or the heater element. Test power cord for continuity with a 110-volt voltmeter or 110-volt test light; test heater element continuity with an ohmmeter or 12-volt test light.
(1) Drain coolant from radiator and cylinder block. (Fig. 15).
(2) Detach power cord plug from heater.
(3) Loosen screw in center of heater. Remove heater assembly.
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly with element, loop positioned upward (Fig. 14).
(3) With heater seated, tighten center screw securely to assure a positive seal.
(4) Fill cooling system with coolant to the proper level, then inspect for leaks.
|Engine Size||B, F, G, 318|
|CAPACITY (Including Heater and Coolant Reserve System)|
|U.S Quarts/Radiator Width||15.5 (14.7L) / 26"
(66 cm) (A,B)
16.5 (15.6L) / 26" (66 cm) (C)
|FAN SHROUD USED|
|Without Air Conditioning|
|With Air Conditioning|
|With Maximum Cooling Pkg.|
|THERMOSTAT SETTING||195�F (91�C)|
|FAN DRIVE TYPE|
|Without Air Conditioning|
|With Air Conditioning|
|With Maximum Cooling Pkg.|
|Without Air Conditioning|
|With Air Conditioning|
|With Maximum Cooling Pkg.|