SERVICE MAN. UPDATE-SEC. 1A 1B HEATER CORE R & R

SUBJECT: SECTIONS 1A, 1B - HEATER CORE (FRONT)

VEHICLES AFFECTED: 1990-93 "U" VANS"

Bulletin revised to cancel and supersede the front heater core and cover procedures found in Sections 1A or 1 B of the 1990-93 U-Van Service Manuals. Use this procedure whenever service of the heater core is necessary.

APPLICATION:

1990 Through 1993 Chevrolet Lumina APV And APV Cargo 1990 Through 1993 Pontiac Trans Sport

HEATER CORE (FRONT)

Figures I through 9

Remove or Disconnect

0 Drain engine coolant. Refer to SECTION 6B. 1. Two screws (838) attaching RH windshield wiper transmission (837) arm to windshield wiper frame (836) . 0 Move RH windshield wiper transmission arm aside to gain access to heater hoses. 2. Clamp and heater outlet hose (105) from heater core (123). 3. Clamp and heater inlet hose (104) from heater core (123). 4. RH I/P sound insulator panel push-in retainers (803), screw (806) and nut (805) from stud. 0 Carefully pull RH I/P sound insulator panel (802) away from I/P . 5. Floor (courtesy) lamp (804) from RH I/P sound insulator panel (802). 6. RH I/P sound insulator panel (802) from vehicle. 0 Open I/P compartment door. 7. Three screws (809) from bottom of I/P compartment insert (808) . 8. Three upper I/P compartment screws (809) with two bumpers (810) . 9. Electrical connector from I/P compartment lamp and switch assembly. 10. I/P compartment (with door) (808) from I/P . 11. Bolt (113) and nut (115) from I/P lower brace (114) (early model vehicles) 12. I/P lower brace (114) from I/P (early model vehicles). 13. Two screws (839) retaining I/P lower extension housing (801) to I/P lower extension support bracket (840) . 14. RH I/P outer support to I/P lower trim pad attaching bolt (812) . 0 Position wedge between RH I/P outer support (811) and I/P lower trim pad (807). 15. Heater and A/C control vacuum harness (117) from vacuum/electric solenoid (116) . 16. Two screws retaining vacuum/electric solenoid (116) . 17. Vacuum/electric solenoid (116) from heater core cover (112) . 18. Six screws (147) and two clips (122) from heater core cover (112) . 19. Heater core cover (112) and seal (118) from temperature case(l26) . 20. Heater core lower bracket retaining screw (late model vehicles). 21. Heater core lower bracket (late model vehicles). 22. LH retaining screw from heater core upper bracket (late model vehicles). 0 Loosen RH retaining screw from heater core upper bracket (late model vehicles). 0 Adjust heater core upper bracket to allow heater core removal. 23. Heater core inlet/outlet tubes from tube/case seal (120). 24. Heater core (123) and seal (119) from temperature case (126) .

Inspect 1. Heater core (123) for signs of damage, leakage or internal restriction. Repair or replace as necessary. 2. Tube/case seal (120) for damage or deformation. Replace as necessary. 3. Heater core seals (118 and 119) for damage or deformation. Replace as necessary.

Install or Connect 1. Heater core inlet/outlet tubes into tube/case seal (120) and heater core (123) and seal (119) into temperature case (126) (adjusting heater core upper bracket if equipped) 2. LH retaining screw to heater core upper bracket - do not fully tighten (late model vehicles). 3. Heater core lower bracket with retaining screw (late model vehicles). 0 Adjust positioning of heater core in temperature case to prevent any movement. Tighten 0 Heater core bracket retaining screws to 3 N.m (27 lb.in.) 4. Heater core cover (112) and seal (118) to temperature case (126) with six screws (147) and two clips (122) . Tighten 0 Heater core cover screws (147) to 7 N.m (62 lb.in.). 5. Vacuum/electric solenoid (116) to heater core cover (112) with two screws. Tighten 0 Vacuum/electric solenoid screws to 7 N.m (62 lb.in.). 6. Heater and A/C control vacuum harness (117) to vacuum/electric solenoid (116). 0 Remove wedge from between RH I/P outer support (811) and I/P lower trim pad (807) . 7. RH I/P outer support to I/P lower trim pad attaching bolt (812). Tighten 0 RH I/P outer support to I/P lower trim pad attaching bolt (812) to 10 N.m (89 lb.in.). 8. Two screws (839) retaining I/P lower extension housing (801) to I/P lower extension support brackets (840) . Tighten 0 I/P lower extension housing to I/P lower extension support bracket screws to 3 N.m (27 lb.in.). 9. I/P lower brace (114) with nut (115) and bolt (113) (early model vehicles). Tighten 0 I/P lower brace nut (1 15) to 1 0 N.m (89 lb.in.). 0 I/P lower brace bolt (1 13) to 8 N.m (71 lb.in.). 10. Electrical connector to I/P compartment lamp and switch assembly while positioning I/P compartment into I/P (with door open). 11. Three upper I/P compartment screws (809) with two bumpers (81 0) 12. Three lower I/P compartment screws (809) . Tighten 0 I/P compartment screws (809) to 3 N.m (27 lb.in.). 0 Close I/P compartment door. 13. Floor (courtesy) lamp (804) to RH I/P sound insulator panel (802) while positioning panel into I/P. 14. RH I/P sound insulator panel screw (806), nut (805) and push-in retainers (803). Tighten 0 RH I/P sound insulator panel attaching screw (806) to 3 N.m (27 lb.in.). 15. Heater inlet hose (104) to heater core (123) and secure with clamp. 16. Heater outlet hose (1 05) to heater core (123) and secure with clamp 217. Two screws (838) attaching RH windshield wiper transmission (837) arm to windshield wiper frame (836). Tighten 0 RH windshield wiper transmission arm-to-windshield wiper frame screws (838) to 7 N.m (62 lb.in.). 17. Refill engine coolant. Refer to SECTION 6B.

WARRANTY INFORMATION:

For vehicles repaired under warranty use:

Labor Operations: D2800, D2802, D2820 and D2822 New Labour Time: 1.2 Hrs.

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.