Yanmar 4BY, Service Manual

Page: 171 / 275

COOLING SYSTEM
7-12
BY Service Manual
Repair
Draining and Filling Closed Cooling
System
1. Remove coolant filler cap from heat exchanger.
2. Remove the heat exchanger to access the
cylinder block drain plug behind it. See Remove
and Install Heat Exchanger on page 7-16.
Figure 7-7
Note: The charge air cooler has been removed
for clarity of photo (Figure 7-7) .
3. Remove drain plug (Figure 7-7, (1)) from the
engine block. Allow coolant to drain into a
container of appropriate size.
4. Install cylinder block drain plug with a new
gasket.
Figure 7-8
5. Install heat exchanger. See Remove and Install
Heat Exchanger on page 7-16. Ensure the
drain cock (Figure 7-8, (1)) on the heat
exchanger is closed.
6. If not already done, remove the filler cap
(Figure 7-8, (2)) from the heat exchanger.
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.
0000002enMarine
000 3 660
(1)
000 3 659A
(2)
(1)