Chevrolet 70 1969 Series, Shop Manual

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SECTION 13
RADIATOR AND SURGE TANK
All radiator core assemblies consist of three
components: Upper tank, center core section and
the lower tank. All tilt cab models employ a surge
tank mounted above the level of radiator core.
Pressure cooling is used on all vehicles. Cool­
ant in a pressurized system does not boil until
temperature exceeds the normal boiling point of
water. Also, in pressurized system coolant is not
lost by evaporation.
Cooling system pressure relief valve is in­
tegral with filler cap on all models.
Cooling system pressure control is arranged
so that excessive pressure is released through
system overflow line which directs coolant out
below the engine. This prevents the possibility of
spray on ignition wiring and spark plugs.
RADIATOR M O U N T IN G
On all conventional models except H V , JV-70
Models, radiator is set in semi-shear type sup­
ports and is held in place at the top by a bracket
which is bolted to the front end radiator shell
(fig. 1).
Radiators in HV, JV-70 Models are trunnion
mounted with strut rod provided at each side to
adjust and maintain position of radiator. Figure 2
illustrates radiator installation in HV, JV-70
Models.
Figure 1—Radiator Shell Flexible Mounting
On 70 and 80 Series
“ J ”
Models, the radiator
is mounted the same as in the “ H ” models with
different semi-shear type r a d i a t o r support
brackets and strut rods as shown in Figure 3.
Radiator on tilt models 70 and 80 is bolted to
a support frame. Bottom of support frame is
attached to a mounting bracket. Top of support
frame is mounted on each side to the control
island frame. Radiator support mounts for these
models are shown in figure 4.
IMPORTANT
At regular intervals check and
tighten core support attaching bolts
and nuts.
RADIATOR CORE REPLACEMENT
C O N V E N T IO N A L M O D E L S (E X C E P T HV, JV-70)
Removal (Refer to Fig. 1)
1. Drain radiator.
2. To provide clearance, remove two bolts
which attach hood center panel to radiator shell
and then support front of hood center panel by
placing a prop between top of engine and panel.
Figure 2 — Ra dia tor Installation (Typical for
H V a n d J V 7 0 M o d e ls)
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L