G 3500 1 Ton Van V8-454 7.4L (1989)
Evaporator Core: Service and Repair
FRONT UNIT
1.
Disconnect battery ground cable, then discharge system refrigerant.
2.
Remove coolant recovery tank and bracket.
3.
Disconnect electrical harness connections from core case assembly.
4.
Remove bracket at evaporator case, and right front marker lamp assembly to provide access.
5.
Disconnect inlet and discharge lines at accumulator. Cap all open connections. Remove accumulator mounting brackets and accumulator unit.
6.
Remove evaporator inlet line.
7.
Remove core case and housing assembly from vehicle.
8.
Separate case halves, then remove evaporator core.
9.
Reverse procedure to install, using new "O" rings coated with clean refrigerant oil at connections.
OVERHEAD SYSTEM
1.
Disconnect battery ground cable, then discharge system refrigerant.
2.
Remove rear duct.
3.
Disconnect blower motor harness and ground wire.
4.
Disconnect refrigerant lines at evaporator/blower assembly. Cap all open connections.
5.
While supporting unit, remove blower/evaporator assembly support screws at roof rail. Place unit upside down on bench, then remove upper to
lower case retaining screws. Remove lower case half.
6.
Remove upper case to support screws and case from evaporator core.
7.
Remove inlet and discharge lines at expansion valve. Cap all open connections.
8.
Remove expansion valve sensing bulb from discharge line, then the valve.
9.
Remove plastic screen retaining pins at core and screen.
10.
Reverse procedure to install, using new "O" rings coated with clean refrigerant at connections. When installing a new evaporator core, add 3 fluid
ounces of fresh refrigerant oil to unit prior to installation.