Westerbeke 6.5KW Technical Manual page 78

Cooling System Troubleshooting
1.
Trouble possible Cause Remedy
Coolant leaks: It is recommended that when
leak in the cooling system that the system
using commercially available pressure tester
iST255. Follow instructions with the tester.
the leak.
trying to locate a
be pressure tested
such as the STANT
Locate and correct
2. Leaking pressure
cap
3. Faulty plastic
coolant recovery
tank
2. Test with above unit
and/or replace.
3. Check and tighten con-
nections or replace
tank.
2. Overheating (Fresh 1. Insufficient 1. Replenish coolant and
check for cause of
loss.
Water System) coolant
3. Overheating (Raw
Water System)
2. Loose or broken
water pump drive
belt
3. Faulty thermostat
4. Faulty overheat
switch
5. Scale and sediment
in cooling system
6. Faulty circulating
pump
2. Adjust or replace.
3. Remove and replace.
4. Remove and replace.
5. Flush engine cooling
system and heat ex-
changeri replenish
coolant.
6. Remove and replace.
1. Loose or broken raw 1. Adjust or replace.
water pump drive
belt
2. Faulty raw water
pump
3. Clogged heat
exchanger
4. Scale in exhaust
2. Check raw water pump
for wear, defective
impeller. Repair or
replace as needed.
3. Remove exchanger,
clean and flush.
4. Remove elbow and clean
Other causes of eng ine overheating may be caused from faults in the
raw water circuit supplying coolant to the raw water pump on the
engine. Examine the off circuit for possible contributing faults.
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