For 1990-2009 cars

# SERVICE MANUAL UPDATE-SEC. 1B FRONT EVAPORATOR CORE R & R

#### Subject: SERVICE MANUAL UPDATE, SECTION 1B, FRONT EVAPORATOR CORE R AND R

#### Models Affected: 1990-93 TRANS SPORT MODELS

The service procedure contained in this bulletin supersedes the procedure published in Trans Sport Service Manuals for the 1990-93 model years.

#### FRONT EVAPORATOR CORE R AND R

Remove or Disconnect:

1. Battery negative cable. 2. Discharge and recover refrigerant from A/C system. Refer to HEATER, VENTILATION AND AIR CONDITIONING (Section 1B). 3. Heater core: a. Drain engine coolant. Refer to COOLING AND RADIATOR (Section 6B). b. Screws (2) retaining RH windshield wiper linkage to drive arm and position linkage to side. c. Clamps (2) from heater inlet/outlet hoses. d. Heater inlet/outlet hoses from heater core nipples. e. Screw, nut and push-in retainers (2) securing RH sound insulator panel, floor lamp from panel and panel from I/P. f. Screws (6) retaining glove box and glove box (w/door) from I/P. g. Screw and nut retaining I/P brace and brace from I/P (not required on 1993 models). h. Screws (2) retaining I/P lower extension housing at lower brackets (1993 models only). i. Screw retaining I/P lower trim pad at RH corner. j. Position a wedge between the RH corner of the I/P lower trim pad and pillar to maintain pad in a slightly rearward position. This will provide sufficient clearance for core service. k. Vacuum harness from vacuum solenoid. l. Screws (2) retaining vacuum solenoid to core cover and solenoid from cover. m. Screws (6) retaining heater core cover and cover from module. n. Heater core lower bracket screw and bracket from core. o. Heater core upper bracket screws (installation will be much easier if upper right screw is not completely removed). p. Heater core from module. 5. I/P trim pad. Refer to Instrument Panel (Section 8C). 5. Harness from temperature door electric actuator. 6. Screws (2) retaining temperature door electric actuator and actuator from module. 7. Screws (3) (2 lower, 1 upper right) retaining temperature door housing to module. 8. Screw (1) (upper left) retaining temperature door housing and housing from module. 9. Screws (4) retaining evaporator case to module (engine side). 10. Evaporator inlet/outlet fittings. 11. Flexible defroster duct (above evaporator core). 12. Evaporator pipes from grommet and evaporator from vehicle. 13. Disassemble evaporator core components: a. Tube and drain seal from evaporator core. b. Screw (1) retaining evaporator inlet tube and clamp (1). C. Evaporator case clips (4). d. Separate upper and lower evaporator case halves. e. Evaporator filter stake retainers (6) and filter from evaporator core.

Install or Connect:

1. Assemble evaporator core components: a. NEW evaporator core mounting spacers (2) to NEW evaporator. b. Upper and lower case halves to evaporator core. C. Evaporator case clips (4). d. Evaporator inlet tube clamp (1) and screw (1). e. NEW evaporator core seal (around perimeter of core). f. Evaporator filter and retainers (6). 9. Tube and drain seal to evaporator core. 2. Evaporator to module. 3. Flexible defroster duct. 4. Screws (2) (upper) retaining evaporator case to module (finger tighten only). 5. Screws (2) (lower) retaining evaporator case to module and tighten screws (4). 6. Evaporator drain outlet seal to evaporator case. 7. Evaporator inlet/outlet fittings. 8. Temperature door housing and screws (3) (2 lower, 1 upper right). 9. Screw (1) (upper left) retaining temperature door housing. 10. Pipe grommet. 11. Temperature door electric actuator and screws (2). 12. Harness to temperature door electric actuator. 13. I/P trim pad. Refer to Instrument Panel (Section 8C). 14. Heater core: a. Heater core to module. b. Heater core lower bracket and screw. c. Heater core upper bracket screws. d. Heater core cover and screws. e. Vacuum solenoid onto core cover and screws. f. Vacuum harness onto solenoid. g. Remove wedge at RH corner of trim pad. h. Screw retaining RH corner of I/P lower trim pad. i. Screws (2) retaining I/P lower extension housing at lower brackets (1993 models only). j. I/P brace, screw and nut (not required on 1993 models). k. Glove box (w/door) and screws. l. RH sound insulator panel, floor lamp, screw, nut, and push-in retainers. m. Heater inlet/outlet hoses onto heater core nipples. n. Clamps onto heater inlet/outlet hoses. o. RH wiper linkage and screws. p. Battery negative cable. q. Refill engine coolant. Refer to COOLING AND RADIATOR (Section 6B). 15. Evacuate, charge and leak test A/C system. Refer to HEATER, VENTILATION AND AIR CONDITIONING (Section 1B).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.