# 71 lemans heater core swap



## MEANGREEN71 (Dec 2, 2010)

Hit, just joined the forum in hopes of fig out how to change my heatercore. ive done just about everything else but this over the course of the four gtos ive had. IT IS AN A/C CAR, SO IM HOPING THIS MAY MAKE IT EASIER! I have the glove box and the bottom plastic air/dash valance out. but looking at the heater box, i have no idea where to start.. how much more do i have to pull, where are the bolts and cant his be done from the engine bay?
Thanks for any help I can get!!!!


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## BearGFR (Aug 25, 2008)

Hey Rob,

I've got a 69 Service Manual, dunno how similar they are but just in case, here's what it says:

1. Drain radiator
2. Remove heater hoses at their connections beside the air inlet assembly.

NOTE: The hose from the water pump must go to the top heater core pipe: the other hose runs from the rear of the R.H. cylinder head with V-8 engines or from the center of the block with L-6 engines to the lower core pipe.

3. Remove (5) nuts from the core case studs on the engine side of the dash.
4. Inside the vehicle, pull the entire heater assembly from the firewall.
5. Remove the bowden cables and all electrical connectors from the heater assembly and remove assembly.
6. Remove the core tube inlet seal and core assembly retaining strips and remove core.
7. Install replacement core.

NOTE: Be sure the core to case sealer is intact before installing core. Use new sealer if necessary.

8. Install core retaining strips and core tube seal.
9. Within the vehicle insert the five studs on heater through the holes in cowl and blower and air inlet assembly. Install the case to firewall mounting nuts (on engine side).

NOTE: It may be necessary to first insert coolant tubes through the dash followed by the five studs.

10. Replace the bowden cables and electrical connectors.
11. Replace heater hoses, being careful to install them in their proper location.
12. Refill radiator.


Also, on my car at least in order to get to the blower motor on the firewall you have to remove the passenger side inner fender. It's easier to just pull the whole fender.
Hope this helps.

Bear


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## 1970 Lemans (Jul 25, 2009)

To expand on Bear's commentary:

Actually, on 70-72, there are only 4 studs with the nuts on the engine side. There are also 2 screws (sheet metal) on the passenger compartment side that you will need to remove to undo the heater box.

As Bear mentions, the nut to the lower right stud (as viewed from compartment) is concealed inside the passenger inner fender well. The corrrect procedure is to either remove the inner fender well or whole fender (as Bear mentions), or one can air chisel out an access panel placed in the inner fender well )placed there for this express purpose) to gain access to the stud.

I replaced my heater core in 2009 and elected to drill out the stud from inside using a 3/8 inch bit. This obviously mars the box, so not ideal, but relatively easy. I refilled the whole with caulk prior to reassembly.


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## MEANGREEN71 (Dec 2, 2010)

Thank you both!! Im goin out to finish the job today...so i may try cutting out an access panel. if it doesnt work i guess ill be removing the inner fender.. Thanks!


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