Heater Case - Chevrolet 10 1971 Series Chassis Service Manual

HEATER AND AIR CONDITIONING 1A-28
Fig. 35— Evaporator and Blower Assembly
6. Connect the line from the evaporator core to the
expansion valve using a new "O" ring, coated with
clean refrigeration oil.
7. If a new evaporator was installed, add three fluid
ounces of refrigeration oil to the system.
battery ground cable.
tem. Check performance.
BLOWER A N D EVAPORATOR CASE
Removal (Fig. 35)
1. Purge the refrigeration
radiator.
2. Disconnect battery ground cable.
3. Unclip the blower motor wire at the blower flange
terminal.
4. Disconnect heater hoses at the core tubes.
5. Disconnect the refrigerant lines at the POA valve
outlet and the expansion valve inlet.
connections.
6. Remove vacuum hoses to vacuum reservoir and
plenum air valve actuator.
7. Disconnect temperature door cable.
8. In order to gain access to the lower outboard case
attachments, the right front fender skirt should be
loosened and moved. Remove enough skirt mounting
screws and bolts (from the rear forward) to move
the skirt a sufficient amount.
9. Remove the case retaining screws and sheet metal
nuts. Pull the case away from the mounting studs
and inboard to remove it.
Installation
1. Check the position of the blower and evaporator case
to firewall seals then position the case over the studs
projecting through the firewall and attach the screws
and nuts to retain the case.
motor ground strap.
and firewall at the screw next to the temperature
door lever.
2. Remount the right front fender skirt.
3. Connect temperature door cable and vacuum hoses
(hose to engine vacuum source attaches to vacuum
tank connection nearest the engine).
Connect
Evacuate and charge the sys­
system and drain the
Cap all open
Connect the blower
Replace spacer between case
4. Connect the refrigerant hoses to the expansion valve
inlet and the POA outlet using new "O" ring seals,
coated with clean refrigeration oil.
Connect the heater hoses to the core tubes (fig.
5.
6. Connect the blower motor wire to the motor flange
terminal, and connect the battery ground cable.
7. Refill the cooling system, and evacuate and charge
the refrigeration system.

HEATER CASE

37)
Removal (Fig.
1. Drain the radiator. Disconnect battery ground strap.
2. Remove the heater hoses from the core tubes.
Remove the sheet metal nuts from the heater case
3.
studs which project through the firewall to the engine
side.
4. Remove the glove box.
Unplug the relay connector.
5.
6. Remove the right ball outlet hose.
7. Remove the screw attaching the dash outlets air
distributor to the heater case and move distributor
away from case.
8. Remove the heater case to firewall retaining screws.
9. Pull the heater case away from the firewall and
reach in and disconnect the resistor connector.
10. Remove the resistor harness grommet and remove
the harness from the case.
case.
Installation
1. Place the heater case under the dash and insert the
resistor harness and install the grommet and con­
nect the resistor connector.
2. Position the heater case against the firewall and
push it into place.
between the case and firewall.
case to firewall retaining screws.
Position the dash outlets distributor against the
3.
heater case, insert the forward lip into the retaining
clip, and install the retaining screw.
4. Install the right dash outlet hose.
Connect the relay connector.
5.
6. Install the glove box.
7. Install the sheet metal nuts to the heater case studs
which project forward through the firewall.
8. Attach the heater hoses to the core tubes and con­
nect battery ground strap.
9. Refill the engine cooling system and test system
operation.
HEATER CORE
Removal
1. Remove the heater case as outlined under Heater
Case.
2. Remove the screws retaining the core mounting
straps.
Remove core.
3.
Installation
1. Install the core into the case and seal it with non­
hardening sealer.
2. Mount the core with the core straps and retaining
screws.
Replace the heater case in the vehicle as outlined
3.
under Heater Case.
Withdraw the heater
Check that nothing is pinched
Install the heater
10-30 CHEVROLET TRUCK SERVICE MANUAL
36).