Chrysler Town, Dodge Caravan. Manual — part 72
RADIATOR DRAINCOCK
REMOVAL
CAUTION: Use of pliers on draincock is not recom-
mended. Damage may occur to radiator or drain-
cock.
NOTE: It is not necessary to remove draincock dur-
ing a routine coolant drain.
(1) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(2) Open the draincock by turning it counterclock-
wise until it stops.
(3) Turn the draincock back (clockwise) 1/8 turn.
(4) Pull the draincock (Fig. 16) from the radiator
tank.
INSTALLATION
(1) Align draincock stem to radiator tank opening.
(2) Push draincock into the radiator tank opening.
(3) Tighten the draincock by turning clockwise
until it stops.
(4) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 17).
Fig. 15 Radiator to A/C Condenser Mounting (left
mount shown, right similar)
1 - SCREW - A/C CONDENSER SIDE BRACKET TO RADIATOR
2 - LOWER MOUNT
3 - A/C CONDENSER
Fig. 16 Draincock
1 - RADIATOR TANK
2 - DRAINCOCK
Fig. 17 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
7 - 26
ENGINE
RS
RADIATOR (Continued)
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose. If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 17) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP TESTING
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700 (Fig. 18). Working
the plunger, bring the pressure to 104 kPa (15 psi) on
the gauge. If the pressure cap fails to hold pressure
of at least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing 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.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 18), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
DIAGNOSIS AND TESTING - RADIATOR CAP
TO FILLER NECK SEAL
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 19). Attach the
Radiator Pressure Tool to the filler neck nipple and
pump air into the radiator. Pressure cap upper gas-
ket should relieve at 69-124 kPa (10-18 psi) and hold
pressure at 55 kPa (8 psi) minimum.
Fig. 18 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
Fig. 19 Radiator Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RS
ENGINE
7 - 27
RADIATOR PRESSURE CAP (Continued)
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 OR UNDER PRESSURE.
There is no need to remove the radiator cap at any
time except for the following purposes:
(1) Check and adjust coolant freeze point.
(2) Refill system with new coolant.
(3) Conducting service procedures.
(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP. THEN
PLACE A SHOP TOWEL OVER THE CAP AND WITH-
OUT PUSHING DOWN ROTATE COUNTERCLOCK-
WISE TO THE FIRST STOP. ALLOW FLUIDS TO
ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS PUSH DOWN AND REMOVE THE CAP COM-
PLETELY. SQUEEZING THE RADIATOR INLET HOSE
WITH A SHOP TOWEL (TO CHECK PRESSURE)
BEFORE AND AFTER TURNING TO THE FIRST
STOP IS RECOMMENDED.
CLEANING
Use only a mild soap to clean the pressure cap.
INSPECTION
Hold the cap in your hand, top side up (Fig. 20).
The vent valve at the bottom of the cap should open.
If the rubber gasket has swollen, preventing the
valve from opening, replace the cap.
Hold the cleaned cap in your hand, upside down.
If any light can be seen between vent valve and the
rubber gasket, replace the cap. Do not use a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures coolant
return to the radiator.
RADIATOR FAN
DESCRIPTION
The dual radiator fans are mounted to the back
side of the radiator (Fig. 21). The radiator fan consist
of the fan blade, electric motor and a support shroud
which are all serviced as an assembly.
Fig. 20 Cooling System Pressure Cap
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
7 - 28
ENGINE
RS
RADIATOR PRESSURE CAP (Continued)
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE
A/C PRESSURE
TRANSAXLE OIL
TEMPERATURE
Fan
Operation
Speeds:
Initial
Max
Initial
Max
Initial
Max
Fan On:
104°C
(220°F)
110°C
(230°F) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%
1,724 Kpa
(250 psi)
2,068 Kpa
(300 psi) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%
96°C (204°F)
111°C (232°F)
Fan Speed
Duty Cycles
(Ramps-up)
from 30% to
99%
Fan Off:
101°C
(214°F)
Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%
1,710 Kpa
(248 psi)
Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%
89°C (192°F)
Fan Speed
Duty Cycles
(Ramps-down)
from 99% to
30%
DIAGNOSIS AND TESTING - RADIATOR FAN MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION
POSSIBLE CAUSES
CORRECTION
NOISY RADIATOR FAN
1. Fan blade loose.
1. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
2. Fan blade striking a surrounding
object.
2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or A/C
condenser.
3. Remove obstructions and/or
clean debris.
4. Electric fan motor defective.
4. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
ELECTRIC FAN MOTOR DOES
NOT OPERATE
1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor, or wiring defective.
1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Defective A/C pressure
transducer.
2. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
ELECTRIC RADIATOR FAN
OPERATES ALL THE TIME
1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor or wiring defective.
1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Check for low coolant level.
2. Add coolant as necessary.
3. Defective A/C pressure
transducer.
3. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
RS
ENGINE
7 - 29
RADIATOR FAN (Continued)
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