Heater Core replacement help

[Bigru]

I'm in need of some help, I have a 65 SWB with factory air and I'm trying to replace the heater core, blower motor and evaporator. I started by removing the screws on the top of the heater core, then I realize I couldn't get the core out that way. Do I need to drop the factory ac unit in the cab to remove the heater core and blower box in the engine bay? Does anyone have any pics or a video of this removal process? Thanks for the help!

[Bigru]

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[newbe351]

There are two speed nuts in the firewall in the cab that need to be removed to get the heater box out. You need a deep socket to get to them. I forget the size......

[Bigru]

I can't see the screws because the AC box is in the way, now I have to remove AC box. Any how to's on that.

[chevyrestoguy]

The A/C box is bolted in four locations. Two of the studs protrude through the firewall and you have to access them from the engine bay side. The other two points are the bracket with two bolts that fasten to the bottom lip of the dash. There are a bunch of mechanical cables and a wire harness that also attach to the A/C box that will need to be disconnected.

Before you go that far, consider this:
One thing to remember on your heater core.....the A/C trucks had a special heater core that has a flapper door that shuts off the air to the heater core so you won't get hot air when the A/C is turned on. You have to undo the cable on that flapper before the heater box will come out! This cable routes behind the A/C box and will be pointing straight up and the eyelet on the end will attach to the lever on the flapper door. If you can't see it from the bottom, then remove the glove box liner and you'll see it clearly, and you will be able to see the mount studs for the heater box as well.

If you look at my '64 build thread, there is a picture of the firewall from the inside of the cab. You will see a rectangular-shaped hole between the two mounting stud holes for the heater box. This is where the flapper door is located. The non-A/C trucks will not have this hole in the firewall.

I just reread your initial post on this thread. If you plan to replace the evaporator, you will need to remove the A/C box. The only way to get the evap out is to have the box on the bench because you have to remove the top cover and you can't do that in the truck.

I'm doing this exact same job right now. Feel free to PM me with any questions!

[Bigru]

Originally Posted by chevyrestoguy

The A/C box is bolted in four locations. Two of the studs protrude through the firewall and you have to access them from the engine bay side. The other two points are the bracket with two bolts that fasten to the bottom lip of the dash. There are a bunch of mechanical cables and a wire harness that also attach to the A/C box that will need to be disconnected.

Before you go that far, consider this:
One thing to remember on your heater core.....the A/C trucks had a special heater core that has a flapper door that shuts off the air to the heater core so you won't get hot air when the A/C is turned on. You have to undo the cable on that flapper before the heater box will come out! This cable routes behind the A/C box and will be pointing straight up and the eyelet on the end will attach to the lever on the flapper door. If you can't see it from the bottom, then remove the glove box liner and you'll see it clearly, and you will be able to see the mount studs for the heater box as well.

If you look at my '64 build thread, there is a picture of the firewall from the inside of the cab. You will see a rectangular-shaped hole between the two mounting stud holes for the heater box. This is where the flapper door is located. The non-A/C trucks will not have this hole in the firewall.

I just reread your initial post on this thread. If you plan to replace the evaporator, you will need to remove the A/C box. The only way to get the evap out is to have the box on the bench because you have to remove the top cover and you can't do that in the truck.

I'm doing this exact same job right now. Feel free to PM me with any questions!

Thanks for the info, I wasn't able to see the bolt that holds the flap until I remove the glove box and dropped the AC box. The pics on your thread helped a lot.

[Bigru]

Originally Posted by Woogeroo

ya could try looking.... here:

60-66 FAQ Index

Section 2

under:

Heaters

Great info!! I needed that, Thanks.