3 - 1 6 7 .
G e n e r a l .
S e c t i o n
X X V .
C O O L I N G
G R O U P
The cooling system consists of a radiator, shutter
and shutter controls, and the necessary lines, fit-
tings, and linkage to connect these components.
The shutter is controlled by the shutter control
thermostat, which can also be operated manually.
See f i g u r e 3 - 2 9 to remove hoses and other related
3 - 1 6 8 .
G r i l l e .
~. Replacemerit. Replace grille
( 7 8 ,
f i g .
3 - 2 2 )
(~) Remove screws ( 7 6 , f i g . 3 - 2 2 ) and cage
nuts (77) which secure grille (78) at top and bottom.
(Q) Remove 2 screws (79) which secure
grille at each side and remove grille (78).
(2) Installation. Install grille in reverse order
~. Repair. Repair grille (78) by straightening
cross members and corners. Remove rust or other
corrosion and repaint prepainted surfaces in accord-
ance with services requirements.
3 - 1 6 9 .
F a n
G u a r d .
(1) Remove the 2 screws ( 1 5 a n d 1 7 , f i g . 3 - 2 9 )
which secure the two clamps (16 and 18) on the hy-
draulic cooler lines to the fan guards (25 and 26).
(2 Remove 7 screws (24) which secure fan
guards 25 and 26) to radiator shroud (36) and re-
move both fan guards.
(3) Re-install in reverse order of removal.
b. Repair. Repair fan guard (25 and 26) by
strZig htemng cross members.
Remove rust or other
corrosion and repaint preprinted surfaces in accord-
ance with service requirements.
3 - 1 7 0 .
S h u t t e r
T h e r m o s t a t .
(1) To test shutter thermostat ( f i g . 3 - 3 0 ) opera -
tion, verify that the shutters on the shutter assembly
change from a closed position when the engine is cold,
and to an open position when the engine is at operating
(2) Remove the thermostat ( 6 , f i g . 3 - 3 0 ) .
(Refer to p a r a g r a p h b b e l o w ) .
d thermostat (6) in a container of
c l e a n w a t e r . T h e r m o s t a t must be completely im-
mersed but not touching bottom of container.
(4) Heat water gradually and stir so heat is
Check temperature of water with a re-
liable thermometer. DO not overheat.
(5) Observe thermostat (6) as temperature of
the water increases.
If the thermostat (6) is func -
tioning properly, it should begin to open at 160° F
and be fully open at 202° F.
(6) Thermostat (6) is not adjustable. If it does
not operate within the above limits it must be replaced,
Replace the thermostat (6) as
(a) Drain radiator assembly
( 3 5 ,
f i g .
3 - 2 9 )
by removfig the radiator cap and opening shutoff
(b) Loosen hose clamp (4) which secures
lower hosF (6) to the shutter control assembly.
(c) Remove nuts
f i g .
3 - 3 0 ) which secure
shutter assembly to contro assembly (10) and re-
move the rod (2) from control assembly (10).
(~) Remove the two screws ( 3 , f i g . 3 - 3 1 )
and washers (4) which secure shutter control assem-
bly (5) to the bottom of radiator (17) and remove
shutter control assembly (5) with attached coupling
fitti~-, elbow, drain valve, and drain hose.
(e) Remove two nuts ( 3 , f i g . 3 - 3 0 ) and
studs (4) which secure the control assembly to the
coupling fitting and remove thermostat (6).
(2) Installation. Install the thermostat
f i g .
3 - 3 0 ) in reverse order of removal steps.
3 - 1 7 1 .
S h u t t e r
A s s e m b l y .
Test shutter ( 2 , f i g . 3 - 3 1 ) as follows:
(1) Verify that shutter (2) changes from a
closed position, when the engine is cold, to an
open position when the engine is at operating temp-
(2) Verify shutter (2) opens and closes freely
when operated manually.
With the engine cold and the
ma~ual shutter control in the closed position ad-
just the nuts on the shutter assembly threaded link
shaft to assure that the shutters are fully closed.
Check that with manual shutter control in open posi-
tion, the shutters are opened fully.
Replace the shutter(2) as
(~) Remove ~rille as described in
p a r a g r a p h
3 - 1 6 8 a .
C h a n g e
3 - 8 1