Volvo Penta D4 Series Operator's Manual page 78

Maintenance
76
Checking exhaust line
The exhaust line must be inspected every year, due to
corrosion between the hose (1) and pipe (2).
WARNING!
Risk of water entering. The exhaust line must be
inspected while the boat is on land. In case of serious
corrosion damage, the pipe must be repaired or
replaced with a new one.
1 Remove the hose clamps and remove the hose.
2 Inspect the contact surface (3). The pipe must be
repaired or replaced if there is serious corrosion
damage.
Exhaust pipe sacrificial anode,
check
Applies to engines with a sacrificial anode fitted to the
exhaust pipe.
WARNING!
Risk of water entering. The exhaust line must be
inspected while the boat is on land. In case of serious
corrosion damage, the pipe must be repaired or
replaced with a new one.
The exhaust pipe sacrificial anode (2) must be checked
yearly.
1 Loosen the sacrificial anode holding fixture (1) from
the exhaust pipe.
2 Check the sacrificial anode (2).
Replace with new anode when approximately 1/3
of the anode has corroded away.
3 Mount the sacrificial anode to the holding fixture.
Install the holding fixture with new O-ring.
Grease the sealing surface and screw threads gen-
erously with water resistant grease.
4 Check that no leakage occurs when launching the
boat.
Use sacrificial anodes thus:
• Zinc in salt water.
• Magnesium in freshwater.
• Aluminum when the boat is used primarily in salt
water and sometimes in brackish water.
47702599 12-2011