Subaru 1600 Service Manual page 44

The operation of the cooling system is
as follows:
I) Cooling with thermostat closed
When the coolant temperature is under
the specified degrees, coolant flows
only through the by-pass passage. This
limited coolant circulation reduces
cooling action, thus shortening engine
warm-up time.
By-pass passage:
a. Intake manifold
-+
Carburetor
-+
Thermo valve
-+
Water by-pass base
and pipe
-+
Water pump
When the environmental tempera-
ture around thermo valve exceeds
the specified degrees, the coolant
passage from carburetor to water
by-pass pipe is shut off by means of
thermo valve so that the fuel in
carburetor is not heated.
ENGINE
To intake manifold
t
11:~~1\..-=::=~==~To
radiator
--+
A5-660
Fig. 3-3 Cross section of thermo valve
_.
-.---.~-
--""'I
b. Intake manifold - Thermostat
case~
3-way cock - Water by-pass hose
.\. /andPiPe
He~er
.\.
Water pump
2)
Cooling with thermostat open
When the coolant temperature exceeds
the specified degrees, thermostat
begins to open and coolant flows
through radiator and by-pass passage,
increasing the
cooling function.
3) Cooling with electric fan in opera-
tion
When the coolant temperature exceeds
the specified degrees, the thermo-
switch turns on to operate the electric
fan.
7. Automatic Transmission Fluid Coolin. System
Automatic transmission fluid
cooling system
(SUBARU 1800 AT & 4WD-AT)
The fluid cooling system of automatic
transmission consists of an cooler built
in radiator, pipes and hoses to circulate
fluid between torque converter and
cooler.
Heated fluid circulating through
torque converter returns to cooler and
is cooled by coolant, thereby being
maintained at an adequate tempera-
ture.
1.570 kW (1,350 kcal/h, 5,357 BTU/h)
Radiation
. . p
Oil flow: 6~/min
(l.6 US gal/min, 1.3 Imp gal/min)
capacity Water flow: 20~/min (5.3 US gal/min, 4.4 Imp gal/min)
1 Hose assembly
1·1 Outlet
hOle
1·2 Inlet hose
1-3 Clamp
1-4 Clip
Temperature difference between
water inlet and oil inlet:
Pipe complete
Hose clamp
Cooler
Radiator
Side frame
Fig. 3-4 Component pam of auto-
matic trllflltn/.lon fluid
cooling
'ystem
3-7
30
c
e
(86°F)