Where is the heater core in a gmc van - 1984 GMC VanDura

SOURCE: replace heater core 1994 chevy g20 conversion van

Here a are the instuctions to remove it. I did not know if you have A/C or not so I included both for you.

REMOVAL & INSTALLATION
Without Air Conditioning
ALL MODELS
See Figure 1

1. Disconnect the negative battery cable.
2. Remove the coolant recovery bottle.
3. Place a pan under the van and disconnect the heater intake and outlet hoses. Quickly remove and plug the hoses and support them in an upright position. Drain the coolant from the heater core into the pan.

1. Remove the heater distributor duct-to-case attaching screws and the duct-to-engine cover screw. Remove the duct.
2. Remove the engine cover.
3. Remove all the instrument panel attaching screws.
4. Carefully lower the steering column. Raise and support the right side of the instrument panel. Refer to for further details.
5. Remove the defroster duct-to-case attaching screws and the two screws attaching the distributor to the heater case.
6. Disconnect the temperature door cable. Carefully fold the cable back and out of the way.
7. Remove the three nuts from the engine compartment side of the distributor case and the screw from the passenger compartment side.
8. Remove the heater case and core assembly.
9. Remove the core retaining straps and remove the core.

1. Install the core.
2. Install the core retaining straps.
3. Install the heater case and core assembly.
4. Fasten the three nuts on the engine compartment side of the distributor case and the screw on the passenger compartment side.
5. Connect the temperature door cable.
6. Install the defroster duct-to-case attaching screws and the two screws attaching the distributor to the heater case.
7. Install the steering column.
8. Fasten all the instrument panel attaching screws.
9. Install the engine cover.
10. Install the duct. Install the heater distributor duct-to-case attaching screws and the duct-to-engine cover screw.
11. Connect the heater intake and outlet hoses.
12. Fill the cooling system.
13. Install the coolant recovery bottle.
14. Connect the negative battery cable.

1. Disconnect the battery ground cable.
2. Remove the engine cover.
3. Remove the steering column-to-instrument panel bolts. Lower the column carefully.
4. Remove the upper and lower instrument panel attaching screws. Remove the radio support bracket screw.
5. Raise and support the right side of the instrument panel.
6. Remove the lower right instrument panel bracket.
7. Remove the vacuum actuator from the kick panel.
8. Disconnect the temperature cable and vacuum hoses at the case. Remove the heater distributor duct from over the engine hump.
9. Remove the two defroster duct-to-firewall attaching screws below the windshield.
10. Under the hood, disconnect and plug the heater hoses at the firewall.
11. Remove the three nuts and one screw (inside) holding the heater case to the firewall.
12. Remove the case from the van. Remove the gasket for access to the screws holding the case together. Remove the temperature cable support bracket. Remove the screws and separate the case. Remove the heater core.

1. Install the heater core.
2. Assemble the case and fasten the screws.
3. Install the temperature cable support bracket.
4. Position the gasket, then install the case in the van.
5. Fasten the three nuts and one screw (inside) holding the heater case to the firewall.
6. Connect and plug the heater hoses at the firewall.
7. Fasten the two defroster duct-to-firewall attaching screws below the windshield.
8. Install the heater distributor duct.
9. Connect the temperature cable and vacuum hoses at the case.
10. Install the vacuum actuator at the kick panel.
11. Install the lower right instrument panel bracket.
12. Fasten the radio support bracket screw.
13. Fasten the upper and lower instrument panel attaching screws.
14. Fasten the steering column-to-instrument panel bolts.
15. Install the engine cover.
16. Connect the battery ground cable.
17. Refill the cooling system as necessary.

SOURCE: Heater core

HEATER CORE REPLACEMENT

SOURCE: 1996 GMC Sonoma heater core

the dash has to come out

SOURCE: leaking coolant from rear heater core in my astro van

you can hook the two line together that will fix your problem with no problems

SOURCE: How do you get to the heater core in a 98 GMC Jimmy?

THE STEERING COLUMN (DO NOT ROTATE THE STEERING WHEEL AFTER THE INTERMEDIATE SHAFT IS REMOVE, YOU WILL BREAK THE SIR COIL), WINDSHIELD MOLDINGS, AND DASH HAVE TO BE REMOVED FIRST. UNDER THE HOOD THE BLOWER RESISTOR, R/H INNER FENDER WELL, HEATER HOSES TO THE HEATER CORE AND SEVERAL NUTS AND BOLTS HOLDING THE HEATER PLENUM TO THE FIRE WALL INCLUDING THE HIDDEN BOLT UNDER THE BLOWER RESISTOR IN THE EVAPORATOR CORE AREA. THEN FINALLY THE BOLTS ON THE INSIDE OF THE TRUCK HOLDING THE PLENUM TO THE FIREWALL.

NO DISRESPECT INTENDED BUT IF YOUR NOT A TALENTED MECHANIC I WOULD FIND ONE OR HIRE ONE THAT CAN DO THE JOB FOR YOU. THIS IS QUITE INVOLVED FOR A NOVICE.