HVAC RESTORATION & RENOVATION


This page will detail the renovation of the cabin heating and cooling systems on my 1987 Pontiac Fiero SE/V6. The A/C has worked off and on through my ownership, with a past conversion to R134A. I've also had to replace a heater-core at some point over a decade ago which resulted in a leak in the interior cabin. For reference, here is a simple diagram that I used to help me understand how a car's A/C system functions. Here are some quick links to go directly to the section you're looking for:

  - Removal and Reinstallation of the Heater Core Hoses

  - Repair of the A/C Condensor Unit

  - Reassembly of the In-Dash HVAC Components






HEATER CORE HOSES
11/27/2010
- HEATER CORE SYSTEM:

There's not a whole lot to show here, but as part of my progress from the front of the car to the back, the heater core hoses were the first to be changed as part of the cooling system rebuild. The heater core is housed inside the HVAC unit which is located inside the car under the dash. There are two steel cooling tubes, other than the two primary radiator hoses, which provide hot coolant to the heater core. These tubes seldomly need to be changed, but the hoses in front of the car are often overlooked. These two hoses came from the Fiero Store:

- 85-87 V6/4cyl FT INLET HEATER HOSE (w/ A/C - SMALLER DIAMETER).

- 85-87 V6 FT OUTLET HEATER HOSE (w/ A/C - LARGER DIAMETER).

Swapping out these hoses is pretty self explanitory. If somehow you still have the originals and your heater core has never failed before, then removing these hoses will probably be fairly difficult. The best way to remove these hoses (if stuck) is to cut the old hose off using a sharp razor blade, and then slit the remaining part of the hose down the length of what's left of the hose on the heater core ends. You can then pull off the remaining piece.
These hoses run through a rubber grommet that helps isolate the front trunk compartment from the road below. This is attached by a single 10mm machine screw (make sure to use RTV sealant on this screw when re-installing it, just as the factory originally did). It's a good idea when replacing these hoses to also use new hose clamps. Make sure to properly drain the lines by removing the hoses from the bottom first (see pic).

Note: In the cavity from where the heater core tubes protrude (see image), there was originally a block of foam that filled the void. This block typically deteriorates, and most vehicles will only have remnants of it left. I think there's a better solution here, but haven't come up with it. The area, while open, is still sealed at the heater core end, so this isn't exposing the interior or the HVAC box.









AC CONDENSOR REPAIR
11/20/2010
- CONDENSOR REPAIR:

Unfortunately, I couldn't find a replacement A/C condensor for the Fiero, so my only option was to try to repair or fix the fins on the condensor unit. The condensor is kind of dirty, and I couldn't remove it without destroying the lines, so I decided to leave it in place and just straighten the fins. I used a radiator fin-straightener that I bought from Harbor Freight Tools. You can compare the difference between what it looks like in picture 2 (before) and picture 3 (after). In the fourth picture, I show the tool that I used.

- Harbor Freight : Radiator Fin Straightener - $4.95 (69024).










DASH HVAC REASSEMBLY
3/30/2010
- DASH HVAC SYSTEM:

Before re-installing the dash, I made it a point to clean the entire HVAC system. I replaced or re-glued any part of the foam that was not sealing appropriately. Since I had a heater-core malfunction years back, I figured it needed a good cleaning to get any old residue out. I put everything back, and then re-installed the dash.





 

More coming...

00/00/2010
- NOT STARTED










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