1983 K5 Diesel Heater Core

[helodrvr]

Following the tech writeups on this subject here..but..

I have the fender removed, removed the 3 nuts on the evap housing. Seems like I don't have all I need to pull the heater core housing...more nuts somewhere?

Also, does the evap housing have to be removed to access more of the fasteners for the heater core? My evap housing is fragile...and all caulked to the firewall.

Thank you so much!

 

[Kain]

there is one on the inside and then take a long extension and put on the stud in engine compartment and hammer it out. be easy

 

[helodrvr]

There's a nut on the inside of the evap housing?

 

[Kain]

inside the cab on the right side of it

 

[helodrvr]

Ok, got that one...all the others seem to have nuts on the firewall side. The evap box Is huge so I figured some nuts must be hidden behind it...,no?

The manuals aren't showing that, maybe different for a diesel?

 

[Kain]

ya it has a capture design built in the firewall to hold the box in place its not easy to get out. i think they did that to make it a one man job. there are 3 or 4 in engine compartment then one inside. and the body is the same diesel or gas

 

[helodrvr]

Thank you all! Job done. The issue was I have another cover over all the AC components...needed to pull that apart.

Unfortunately it is so fragile it broke apart..now to find a new one!

 

[tRustyK5]

Yes, the diesel trucks got a heavy sound deadener on the firewall. I carefully cut mine so I could re-use it after the heater core replacement. I probably spent 6 hours doing the heater core on my 83 GMC with the diesel.