Chevrolet Light Duty Truck 1973 Service Manual page 31

4. Remove the glove box and door assembly.
5. Disconnect the Air-Defrost and Temperature door
cables.
6. Remove the floor outlet and remove the defroster
duct to heater distributor duct screw.
7. Remove the heater distributor to dash panel screws.
Pull the assembly rearward to gain access to wiring
harness and disconnect all harness attached to the
unit.
8. Remove the heater-distributor from the vehicle.
9. Remove the core retaining straps and remove the
core.
10. To install, reverse Steps 1-9 above.
NOTE: Be sure core to case and case to dash
panel sealer is intact before assembling unit.
G Models
Replacement (Fig. 6)
1. Disconnect the battery ground cable.
2. Place a clean pan under the vehicle and then
disconnect the heater core inlet and outlet hoses at
the core connections (see "H eater Hoses-Replace-
m ent" later in this section). Quickly plug the heater
hoses and support them in a raised position. Allow
the coolant in the heater core to drain into the pan
on the floor.
3. Disconnect the right hand air distributor hose from
the heater case and rotate it up out of the way.
4. Pry off the temperature door cable eyelet clip and
then remove the bowden cable attaching screw.
5. Remove the distributor duct to heater case screws
and pull the duct rearward out of the heater case
retainer.
6. Remove the four heater case to dash screws and
HEATER A N D AIR C O N D IT IO N IN G
then remove the heater case and core as an
assembly. Tilt the case assembly rearward at the top
while lifting up until the core tubes clear the dash
openings.
7. Remove the core retaining strap screws and remove
the core.
8. To install a new core, reverse Steps 1-7 above.
NOTE: Be sure core to case and case to dash
panel sealer is intact before assembling unit.
HEATER HOSES
Heater hoses are routed from the water pump and
thermostat housing (radiator on automatic transmission
vehicles) to the core inlet and outlet pipes as shown in
Figure 7. Hoses are attached at each end with screw type
clamps.
Replacement
The heater core can be easily damaged in the area of the
core tube attachment seams whenever undue force is
exerted on them. Whenever the heater core hoses do not
readily come off the tubes, the hoses should be cut just
forward of the core tubes. The portion of the hose
remaining on the core tube should then be split
longitudinally. Once the hoses have been split, they can
be removed from the tubes without damage to the core.
CENTER DISTRIBUTOR DUCT - G Models
Replacement (Fig. 8)
1. Disconnect the battery ground cable.
2. Unsnap the engine cover front latches. Remove the
two cover to floorpan screws and remove the cover.
3. Remove the heater core case and core as an
1A-5
LIGHT DUTY TRUCK SERVICE MANUAL