Yanmar 3JH4E Service Manual page 45

7) Check the rubber hose connecting the coolant
recovery tank to the fresh water cooler. Be sure the
hose is securely connected and there is no
looseness or damage.
When the hose is not watertight, an excessive
amount of cooling water will be used.
(7) Clean the exhaust/water mixing elbow.
There are two types of mixing elbows, the L-type and
the U-type. The mixing elbow is attached to the exhaust
manifold. The exhaust gas is mixed with seawater in the
mixing elbow.
1) Clean dirt and scale out of the air pass and
seawater pass of the mixing elbow.
2) Repair the crack or damage of the mixing elbow by
welding, or replace if necessary.
3) Inspect the gasket and replace if necessary.
(8) Adjust the tension of the alternator driving belt.
Refer to 2.2.2(4).
To fresh water
cooler
Rubber hose
Coolant recovery tank
Seawater
L-type mixing
elbow
Gasket
Exhaust manifold
29
2. Inspection and Adjustment
Cap
FULL
LOW