Advertisement
11-2
PART
11-1
GENERAL COOLING SYSTEM SERVICE
Section
1 Diagnosis
and
Testing
Trouble Diagnosis Guide
Cooling
System Pressure Test
Thermostat Tests
2 Maintenance
Page
11-2
11-2
11-3
11-3
11-3
Section
Page
3
Common Adjustments and Repairs
11-4
Drive Belts
11-4
Fan Replacement
11-4
Fan Drive Belt Replacement
11-4
Coolant-Cleaning
Cooling System
Draining and Filling
the
Cooling System
Fan Drive Belts
11-3
11-3
11-3
Radiator Hose Replacement
11-4
Thermostat Replacement
11-4
This part covers general cooling
system
service.
For cooling system
component removal, disassembly, as-
sembly, installation, major repair
D
DIAGNOSIS AND TESTING
DIAGNOSIS
Engine overheating and slow
en-
gine
warm-up are
the two engine
troubles most commonly
attributed
to the cooling
system.
Loss of
coolant,
thermostat
stuck
in
the
closed
position, restricted air
flow through
the
radiator,
or ac-
cumulation
of rust
and
scale in
the
system
are the
main causes of over-
heating.
Coolant
Joss
may,
be due to
external
leakage
at the radiator,
radiator pressure
cap,
water pump,
hose
connections,
heater, or core
TROUBLE DIAGNOSIS GUIDE.
ENGINE OVERHEATS
ENGINE FAILS TO REACH
NORMAL OPERATING
TEMPERATURE OR HAS
WRONG INDICATED
TEMPERATURE
plugs. Coolant loss may also be
caused by internal leakage due to a
defective cylinder head gasket, im-
proper tightening of the cylinder
head bolts, or warped cylinder head
or block gasket surfaces.
Internal leakage can be detected
by operating the engine at fast idle
and looking for the formation of
bubbles in the radiator. Oil in the
radiator may indicate leakage in the
engine block or a leak in the auto-
matic transmission oil cooler. Water
formation on the oil level dipstick
Belt tension incorrect.
Radiator fins obstructed.
Thermostat stuck closed, or other-
wise defective.
Cooling system passages blocked
Thermostat stuck open or of in-
correct heat range.
Temperature sending unit defec-
tive (causing gauge to indicate low
engine temperature).
procedures and specifications, refer
to the pertinent part of this group.
could also be an indication of
intern-
al leakage.
Rust and scale that
form
in the
engine water passages are carried
into the radiator passages by the
circulation of the coolant. This clogs
the radiator passages and causes
overheating.
Rust can be detected by
the appearance of the
coolant.
If
the coolant has a rusty or muddy
appearance, rust is present.
A defective thermostat that re-
mains open will cause slow engine
warm-up.
by rust, scale or other foreign mat-
ter.
Water pump inoperative.
Ignition initial timing incorrect.
Distributor advance incorrect.
Temperature gauge defective
(not
indicating true engine temperature)
or incorrectly installed.
Incorrect temperature gauge
indi-
cation.
Advertisement
