1987 MAZDA 626 Workshop Manual

3A COOLING FAN
WATER THERMO SWITCH
1. Remove the cooling fan water thermo switch.
Note
Make sure that the ignition switch is OFF. If
not, the fan will operate when the connector
is removed.
76G03A-013
76G03A-014
Place the water thermo switch in water.
Heat the water gradually, and check for continui-
ty of the switch with an ohmmeter. Replace if
necessary.
Water thermo switch (ON OFF):
97°C (207°F)....ECE, Hong Kong, Singapore

91
°C (196°F)....General, Middle East
Install the water thermo switch and a new O-ring.
Caution
Do not use sealing tape.
3 A—14

3B
COOLING SYSTEM
(DIESEL)
OUTLINE 3B— 2
COOLANT FLOW CHART 3B— 2
SPECIFICATIONS 3B— 3
TROUBLESHOOTING GUIDE 3B— 3
COOLANT 3B— 4
INSPECTION 3B— 4
REPLACEMENT 3B— 4
RADIATOR CAP 3B— 5
INSPECTION 3B— 5
RADIATOR 3B— 6
REMOVAL AND INSTALLATION 3B— 6
INSPECTION 3B— 6
WATER PUMP 3B— 7
REMOVAL 3B— 7
INSPECTION 3B— 8
INSTALLATION 3B— 8
THERMOSTAT 3B— 9
REMOVAL 3B— 9
INSPECTION 3B— 9
INSTALLATION 3B— 9
COOLING FAN 3B—10
SYSTEM CIRCUIT 3B—10
CIRCUIT INSPECTION 3B—10
FAN MOTOR 3B—11
WATER THERMO SWITCH 3B—12
76G03B-001

3B OUTLINE
OUTLINE
COOLANT FLOW CHART
76G03B-002
1. Water pump 4. Coolant reservoir
2. Thermostat 5. CSD coolant passage
3. Radiator 6. Oil cooler
3B-2

TROUBLESHOOTING GUIDE
3B

SPECIFICATIONS

Cooling system Water-cooled, forced circulation
Coolant capacity liters (US
qt,
Imp
qt)

With heater 9.5 (10.0, 8.4) Coolant capacity liters (US
qt,
Imp
qt)

Without heater 9.0 (9.5, 7.9)
Water pump Type Centrifugal, timing belt driven Water pump
Water seal Unified mechanical seal
Thermostat
Type Wax, two stage
Thermostat
Opening temperature °C(°F) Main Sub
Thermostat
Opening temperature °C(°F)
86.5-89.5 (188-193) 78.5—81.5 (173-179) Thermostat
Full-open temperature °C(°F) 100 (212) 100 (212)
Thermostat
Full-open lift
mm (in)
8.0 (0.31) min. 1.5 (0.06) min.
Radiator
Type Corrugated
fin

Radiator Cap valve opening pressure
kPa (kg/cm2,
psi)
74-103 (0.75-1.05, 11—15)
Cooling
fan

Type Electric
Cooling
fan

Capacity
W
120
Cooling
fan
Switching temprature orvopi OFF
- ON ^
91 (196) Cooling
fan

Number
of
blade 4
Cooling
fan

Outer diameter
mm
(in) 340 (13.4)

76G03B-003
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Overheating
Insufficient coolant Add 3B-
4

Coolant leakage Repair
—

Radiator fins clogged Clean 3B—
6

Radiator cap malfunction Replace 3B—
5

Cooling fan malfunction Repair 3B-11 Thermostat malfunction Replace 3B—
9

Water passage clogged Clean 3B—
4

Water pump malfunction ReDair
or
replace 3B—
7

Corrosion
Impurities
in
coolant Replace 3B-
4

76G03B-004
3B—3

3B COOLANT
86U03X-004
69G03A-006
COOLANT
INSPECTION
Coolant Level (Engine cold)
1. Check that the coolant level is near the radiator inlet
port.
2. Check that the coolant level in the coolant reser-
voir is between the FULL and Low marks.
Add coolant if necessary.
Warning
a) Never remove the radiator cap while the en-
gine is hot.
b)Wrap a thick cloth around the cap when
removing it.
Coolant Quality
1. Check that there is no build-up of rust or scales
around the radiator cap or radiator filler neck.
2. Check that coolant is free from oil.
3. Replace the coolant, if necessary.
Coolant Leakage
1. Connect a tester and SST to the radiator inlet port.
2. Apply 103 kPa (1.05 kg/cm2, 15 psi) pressure
to the system.
3. Check that the pressure is held.
If not, check for coolant leakage.
Warning
When removing either the radiator cap or the
tester, loosen it slowly until the pressure in
the radiator is released, and then remove it.
86U03X-005
REPLACEMENT
1. Remove the radiator cap and loosen the drain plug.
2. Drain the coolant into a suitable container.
Warning
a) Never open the radiator cap while the en-
gine is hot.
b)Wrap a thick cloth around the cap when
loosening.
c) Use caution when draining hot coolant.
86U03X-006
3B—4

RADIATOR CAP 3B
86U03X-028
86U03X-007
86U03X-008
3. Set the heater control switch to the maximum heat
position.
4. Flush the cooling system with water until all traces
of color are gone, then let the system drain com-
pletely.
5. Fill with the proper mixture and amount of ethy-
lene glycol-based coolant.
Caution
a) Do not use alcohol- or methanol-based
coolant.
b) Use only soft (demineralized) water in the
coolant mixture.
Anti-freeze solution mixture percentage

Protection Volume percentage Gravity
at

20°C (68°F) Protection Solution Water
Gravity
at

20°C (68°F)
Above —16°C (3°F) 35 65 1.054
Above -26°C (-15°F) 45 55 1.066
Above -40°C (-40°F) 55 45 1.078

6. Run the engine at idle with the radiator cap re-
moved. Let any air bleed from the system, and add
more coolant.
7. Install the radiator cap, and inspect all connections
for leakage.
RADIATOR CAP
INSPECTION
Radiator Cap Valve
1. Remove foreign material (such as water residue)
from between the radiator cap valve and the valve
seat.
2. Attach the radiator cap to a tester with the SST.
Apply pressure gradually to 74—103 kPa
(0.75—1.05 kg/cm2, 11—15 psi).
3. Wait about 10 seconds; then check that the pres-
sure has not decreased.
Negative Pressure Valve
1. Pull the negative-pressure valve to open it. Check
that it closes completely when released.
2. Check for damage on the contact surfaces, and
for cracked or deformed seal packing.
3. Replace the radiator cap if necessary.
86U03X-009
3B-5

3B RADIATOR
Note
a) Position the hose clamp in the original location on the hose.
b) Squeeze the clamp lightly with large pliers to ensure a good fit. 86U03X-010
RADIATOR
REMOVAL AND INSTALLATION
1. Drain the engine coolant.
2. Remove in the sequence shown in the figure.
3. Install in the reverse order of removal.
1. Coolant reservoir hose
2. Fast idle solenoid
3. Coolant level sensor connector
4. Cooling fan connector
76G03B-005
5. Upper and lower radiator hose
6. Cooling fan and radiator assembly
7. Cooling fan
INSPECTION
Check the following points. Repair or replace if
necessary.
1. Cracks, damage, or water leakage
2. Bent fins (Repair with a screwdriver)
3. Distorted or bent radiator inlet
86U03X-012
3B-6

WATER PUMP 3B
WATER PUMP
REMOVAL
1. Disconnect the negative battery cable.
2. Turn the crankshaft so that the No. 1 cylinder is at TDC of compression.
3. Drain the engine coolant.
4. Remove in the sequence shown in the figure. 69G03A-025
31—46 N m (3.2—4.7 m-kg, 23—34 ft-lb)
19—26 N-m (1.9—2.6 m-kg, 14—19 ft-lb)
(?) 8—11 N-m (80—110 cm-kg, 69—95 In-lb)
37—52 N-m (3.8—5.3 m-kg, 27—38 ft
55—65 N-m (5.6—6.6 m-kg, 41-48 ft-lb)
(80—110 cm-kg, 69—95 In-lb)
59—69 N-m (6.0—7.0 m-kg, 43—51 ft-lb)
76G03B-006
1. Timing belt (Refer to page 1C—11)
2. Camshaft pulley (Refer to page 1C—36)
3. Injection pump pulley (Refer to page
1C—36)
4. Seal plate
Note
Do not disassemble the water pump body, if a problem is found replace it as a unit.
5. Alternator
6. Water pipe
7. Water hose
8. Water pump body
9. Water pump inlet
3B-7