Another Heater Core question

[Rondel Fan]

I have searched and found a few how tos on the site, but I have as yet to find a good set up pictures of the heater core in situ. I have dropped my lower dash across the car and really can't even see all the fasteners needed to drop the heater box. One set of instructions said you have to crack open the A/C system to remove the heater box. I can't believe the engineers would do this, but after R&R'ing the starter and the hard line PS hoses, I guess I've seen worse. If that is the case I'd might be inclined to skip it as I really don't want to open the A/C system.
If any one has pix of the unit installed or of an R&R, I'd love the link.
thcx
Mike

[jps635]

Took me ages to find - these may be of help from when I replaced my heater core. I completely removed my air con unit.

[jps635]

Two more scary ones

[Rondel Fan]

Yes, scary indeed as I can't make out where the core is or was and I am only here!



I should have added my patient is an 86, LHD. Still can't believe they make you drop/open the A/C.

I have no idea what folks did before cell phones could capture pix of the tear down. I often have to leave projects for days or weeks at a time after which the memory fails.

[jps635]

Hang in there. Took me 3 weekends to replace mine. I've added a few more pics so you can see where you're headed and why it is worth persevering. The core itself will have 35 years of crap in it and the sealing between the core and the plastic casing will be absolutely buggered. As you will see would have been about the first component to go in the car when initially assembled.
A few tips:
- disconnect the heater hoses inside the engine bay and gently free up the heater core pipe grommets so they don't tear on removal . Lubricate them with rubber grease.
- Remove the weather cowl above the heater fans if you haven't already. You will see 4 flange bolts that are captive from inside. These are only 5mm or so from memory. When you get at the box you will need to break the flange seal to free up and then clean up from the inside. But before you do so have a good look at and take some photos of how the ventilation duct work all goes together as is a pain in the arse to reinstall.
- 'It may take several attempts to get the heater box back in and you'll need a helper to thread the nuts on while installing from underneath and help pull up. See one of the pics
- Replace all the sealing foam around the core and the heater box sealing flange. I used a selection of various thickness and width self adhesive HD foam rolls.
- Lubricate all the heater control linkages etc and make sure the heater flaps work correctly before going back in
- I managed to keep my heater controls intact (wasn't game to start disconnecting those cables) but had to release the control module and slider plate from the dash panel to give enough slack to get the heater box in the passenger footwell
- on final reassembly the biggest PIA was reconnecting the bloody backlighting so check these as you go. It's really frustrating when you have to do things twice because a bulb holder drops out
- because I never want to go back in there I replaced the heater transistors, the heater outlet thermostat, the heater control module, the heater cabin sensor and the heater valve, but that can be easily got at any time.

[jps635]

Last 2 pics. In the first one you can see where the heater box is located (when it's home)

[Rondel Fan]

Thanks for the info. I will be picking away at it over weekends. How did you know yours was leaking? While I have interior coolant smell, I have not noticed leaking yet, though maybe it is all caught up in the duct work. I'd hate to keep going only to find out it was not leaking. Not to mention having to open and refill the A/C unit.

[jps635]

Mine wasn't leaking, but there was no way i was going to spend $000's rebuilding the engine and replacing everything else and connect up a 32 year old heater. Same with the oil cooler- replaced that with new as well.

[bpoliakoff]

I agree with JPS Pull the heater box out and replace the core. I think I paid about $125 years ago cheap insurance. Do it once do it right and take that out of the equation

[Rondel Fan]

Any other must do items with the dash out?

[bpoliakoff]

Replace the foam seal on the fresh air flapper