air conditioner evaporator core replacement

[wjm]

1994 Chevy 3/4 ton 6.5 turbo diesel surburban

Need procedure to replace air condition evaporator core.

94 3/4 ton 6.5 turbo diesel surburban, gear driven camshaft, banks exhaust system, FSD cooler, 97 dual thermostat water system.

84 3/4 ton 6.2 diesel 400 transmission pickup.

[charliepeterson]

Unfortunately your going deep. Drop the steering wheel column onto the front seat. From the engine side of the fire wall you'll take out four screws, one could be behind the surge tank. Inside the cab on the outboard sides two nuts, one on each side which attach to the supports very close to the interior lights. Take out the bolts which held the brace for the steering shaft. Lift the dash up and out off of the braces outboard.
The dash will lay on the seat with more of it on the right side. The left side won't come down too much, but enough to remove the heater box. Before all this is done remove the coolant hoses and the A/C hoses.
The Evaporator is on the bottom with the heater core sandwiched on top. If you disconnect the fan harnesses and the air diverter door plugs it's not much more to take the HVAC box right out. If you do, take a good look at the circulator door rods. The bushings are plastic and wear out. It doesn't get any easier to replace them now.
This is a big job but if you have the patience you can pull it off.

[wjm]

Thank you for the information on air conditioner evaporator core change over. When I looked at the problem it looks like they started off with the air conditioner and built the truck around it. Your information is very helpful and I will attack this sucker in a couple of weeks.

[BUZZ]

Good luck
Pay extra attention to the sealing of the box. Mine leaks condensate in the floor.
Buzz