Packard Forum Index » V-8 (1955-56)

This is not covered well in the parts book so I thought I would record some info here for reference.

There are essentially 6 parts to the heater core assembly:
- the Air Duct which is in a T shape and includes the baffle
- the Lower Housing which is directly above the Air Duct
- the Upper Housing
- the Core Duct, contained in the Lower Housing (not visible from exterior when assembly is mounted to car)
- the Core, attached to the Core Duct (there is a foam gasket between the Core and the Core Duct flange which matches the depth and dimensions of the flange and is adhered to it)
- the Mounting Plate, attached to the Core Duct and Air Duct

The assembly uses 3 types of screws (all slotted drive, pan head):
- #6 self-tapping, 1/4", blunt tip, Qty 6
- #8 self-tapping, 3/8", pointed, Qty 15
- #10 self-tapping, 3/8", pointed, Qty 4



The general order of assembly is:
- Air Duct to Lower Housing, (4) #10 screws
- Core to Core Duct, (4) #8 screws
- Core Duct to Lower Housing, (2) #8 screws
- Upper Housing to Lower Housing, (6) #6 screws (many people omit the two rear screws so that the Upper Housing may be removed for future service without removing the entire heater core assembly)
- Mounting Plate to Core Duct and Air Duct, (9) #8 screws

The Air Duct often requires service to its baffle. The baffle is attached using (2) 399642 Felt Washers and (2) 399641 Push Nuts. (Note this is slightly different than the fresh air side, which uses one steel washer 101200 on the lever side instead of a nut and felt washer on both.) The high-density foam (often replaced with vinyl) is 8" on the major (long) axis, and 5" on the minor. You do not need to remove the several staples in the duct. Instead, pry up a bit around the edges, and tear out the old material. Cut new material to size and slip it in. See the attached photos below. More detail here.

The baffle hits rubber bumpers attached to the lower part of the Air Duct inside. See photo below. On very rusty assemblies this piece may be missing entirely, or the bumpers may be gone. It is a 5/16 OD, 1/8 tall bumper that fits a 0.115 hole. These seem to be about a perfect replacement.

The hose connections on the Core have foam around them to reduce air leakage. Generally these disentigrate over time and are often missing. This is low-density foam, 5/8" ID, 1/2" wall thickness (1-5/8" OD). This is easily available from the hardware store since it is sold as insulation for copper pipes in the home. It should be cut square on one side, and on the other side cut to the shape that it needs to seal against. See photo below, and reference the diagram in the parts book for the shape. Edit: I hope it's obvious from context but that foam is not supposed to have a crocodile texture. It started life with a normal appearance.

The hose 13643 is 5/8" ID, 1" OD heater hose, and there are (6) "Corbin style" clamps (group 50.675) in total, obviously the 1" type. It is not shown in the diagram, but there should be a 1" rubber-dipped P-Clip (like what is used on the wiring harnesses and vacuum lines) attached to the topmost passenger side water-manifold-to-cylinder-head attachment screw.

The assembly gasket is 3/8" foam (yes, it is really that thick before it is compressed).

For a heater core delete, use a pair of 3/8-18 pipe plugs in place of the 90 and 22½° pipe sections.

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Many moons ago, Packards International used to sell replacement die-cut flapper rubber for 51-56. But most of those projects went AWOL when some key members left the club.

I belive somewhere in my early 54 project blog I show replacing those and stapling them back together.

Thanks. Found your post:packardinfo.com/xoops/html/modules/newbb ... _id=57&post_id=27317#forumpost27317

I don't think anyone ever took this project back up. So for anyone that can make up a die to stamp these out of rubber sheet I think there is probably a market for selling these. Figure every 51-56 that hasn't had there's replaced since they left E. Grand Ave is in need of a pair.

This is not a part that is available from Steele Rubber.

It's a completely flat part, so could be made from bulk rubber sheet.

I wonder if this could be made with a cnc router using a drag knife?

If someone wanted a go at this, they should get the blueprints for the part from Bruce Belvins.

Not a bad idea. Though I have enough part repro projects ATM and the staples are ridiculously hard to get off, so I'm not sure how much market there would be.

Maybe 2 years ago I saw someone selling NOS of those...

Figured NOS ones are probably brittle by now.

The staples are one thing, having a stapler for it is another.

Hence why I reused my old staples. I figure any appropriate sized stiff steel wire that can be bent over without breaking should work. Albeit a manual operation.

Really someone could use a couple small screws or pop-rivets instead.

Olson’s Gaskets could easily make these if they had a good pattern. They would then be able to make more as needed.

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They must have had a very powerful stapler as the staples go through the metal itself, not through pre-drilled holes. If I were designing this now I would just do holes and pop rivets.

Packard used those same staples in many places. I am sure this was some kind of industrial stand mounted, powered apparatus. I don't see two guys at the factory walking around with a 6 foot long Swingline!

The same staples were used to attach the strip of rubber/material around the edges of the wheel skirts and also attach the rubber seal to the gravel guard filler panel between the trunk and the bumper.

Reference photos off of a low mileage, generally original car.

Note: the left P-clip is used only on underseat heater cars. Also, there should be a metal strap around the pair of hoses going to the underseat heater, by the front heater core. Presumably something like 416293 was used originally.

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