Yanmar 6BY2 - Tests and Adjustments; Pressure Test Cooling System and Filler Cap

COOLING SYSTEM
Tests and Adjustments
12/05
BY Service Manual
7-7
© 2009 Yanmar Marine International
TESTS AND ADJUSTMENTS
Pressure Test Cooling System and
Filler Cap
Cooling System
Use a cooling system tester with connections
compatible with the Yanmar BY2 series cooling
system.
1. Remove the filler cap from the heat exchanger.
WARNING! Burn 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.
2. Check that the lugs and sealing flange on the
filler pipe are undamaged and free from
anything that might prevent a good seal.
3. Install the tester and adapter in place of the
filler cap.
4. Pump until pressure is 1.45 bar (21 psi)
(Figure 7-2).
Figure 7-2
Figure 7-2
5. Pressure should hold steady. If the pressure
drops, there is leakage in the system. Start by
checking all hoses and pipe connections.
Filler Cap
1. Connect the cap to the cooling system tester
using the adapter for the cap.
2. Pump until the cap opens (Figure 7-3).
Figure 7-3
Figure 7-3
3. The tester needle should stop at approximately
1.45 bar (21 psi).
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