67 GT500 heater box replacement

[charlie D]

My heater core sprung a leak and it was a result of a mouse nest in the heater core. Everything was rusted terribly, so I decided to replace the entire assembly. The new parts match the old Parts very well. However, I am unable to push the new heater assembly up under the dash into place and get the blower motor to fit through the hole in the firewall. Is there some trick to get this to fall into place. I have been following the instructions in the repairs manual. It has the entire heater box assembled as you push it up under the dash. No way I can get it to go. Any suggestions?

[J_Speegle]

Might be a silly thought but did you remove the glove box liner, the glove box or at least open it to provide some additional wiggle room?

Sometimes it helps to have a second set of hands in the engine compartment guiding the heater hoses and the heater motor (and holding them in place) as you slide it into place. The person in the engine compartment sometimes will have a better view of the heater motor and if your on target with it and the mounting studs

[JWH]

A couple of things to check: 1) I assume you attached the heater hoses to the heater core and you are feeding the hose through the firewall from the passenger compartment side of the firewall. If so, very often the heater hose will fold back on itself between the firewall and the heater box and not allow the box to fully seat in place. Pull the box back out a ways and have someone slowly pull both the hoses through from the engine side of the firewall while you help lift the box up into place. Keep light tension on the hoses as they pull the box up into place to make sure the hoses don't kink or fold back on themselves. 2) there is a metal bracket on the top right of the heater box that helps support the heater box up under the dash and sometimes this bracket gets hung up as you push the box into place.
Jeff
PS - make certain the two wires from the motor go through the firewall cleanly as well, sometimes those can get trapped between the box and firewall too and you have to start over.

[2112]

^^^^good advice above.

I did this job couple months ago. Did not enjoy it one bit.

There is that old joke that a Mustang starts on the assembly line as a heater core and a car gets assembled around it.

[charlie D]

Thanks for the responses. I did remove the glove box door and liner. Also took off the kick panel and removed the passenger seat so access inside is about as good as it gets. Will take another crack at this when I have an extra pair of hands and eyes to be on the engine side.

[69 GT350 Vert]

On my 69, I had to loosen the lower metal dash panel on passenger side to allow clearance for r and r of heater box.  The shop manual instructions specified to do this .  Not sure if necessary on a 67, however.

[Bob Gaines]

On my 69, I had to loosen the lower metal dash panel on passenger side to allow clearance for r and r of heater box.  The shop manual instructions specified to do this .  Not sure if necessary on a 67, however.

Good info for the 69/70 but 65-68 dash is welded in . No harm no foul.