Yanmar 4BY, Service Manual

Page: 176 / 275

COOLING SYSTEM
BY Service Manual 7-17
Repair
Figure 7-16
2. Remove outlet cover (Figure 7-16, (1)) and
spacer (Figure 7-16, (2)) .
3. Remove inlet cover (Figure 7-16, (5)) .
4. Pull core from housing.
5. Remove O-rings (Figure 7-16, (3, 4))
6. Remove zinc anode (Figure 7-16, (7)) and
gasket (Figure 7-16, (6)) .
IMPORTANT
Under no circumstances should caustic
soda be used to clean the components.
7. Use paraffin-based engine detergent to clean
the cooler element. Thoroughly flush and rinse
all components.
8. If any internal deposits remain in the tubes,
consult a local radiator repair shop.
Note: Always install new O-rings.
9. Install new O-rings (Figure 7-16, (4)) on cooler
core.
10. Install cooler core and inlet cover
(Figure 7-16, (5)) .
11. Install one O-ring (Figure 7-16, (3)) between
core and housing (Figure 7-16, (8)) .
12. Install spacer (Figure 7-16, (2)) , remaining
O-ring (Figure 7-16, (3)) , and outlet cover
(Figure 7-16, (1)) .
13. Install new zinc anode (Figure 7-16, (7)) and
washer (Figure 7-16, (6)) . See Check and
Replace Zinc Anodes on page 7-11.
14. Install heat exchanger. See Remove and Install
Heat Exchanger on page 7-16.
Remove and Install Coolant Pump
1. Drain coolant from engine. See Draining and
Filling Closed Cooling System on page 7-12.
2. Remove belt guard.
3. Remove seawater pump belt and alternator
belt. See Remove and Install Alternator on
page 11-7 and Replace Seawater Pump Belt on
page 7-21
.
4. Remove thermostat assembly. See Remove
and Install Thermostat on page 7-19.
000 3 692
(7)
( 8 )
(4)
(6)
(1)
(2)
(5)
( 3 )
A
DANGER
SCALD HAZARD!
• NEVER remove the coolant filler cap if
the engine is hot. Steam and hot
engine coolant will escape and
seriously burn you. Allow the engine
to cool before attempting to remove
the filler cap.
• Securely tighten the filler cap after
checking the coolant level. Steam can
escape during engine operation if the
cap is loose.
• Failure to comply will result in death or
serious injury.
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