Packard Forum Index » V-8 (1955-56)

Greetings,
After 26 years of stewardship I am looking into assemblies on the '56 Patrician that I put so far down on the "to do" list that I thought the next owner probably be dealing with.

I'm down to "issues with the factory AC unit" - tarting-up.

This vehicle did not have the original blower housing to adapter connecter - Group 29.0044 - Part # 469653. this is the connecter between the AC blower and the flange on the firewall. I have not seen another factory AC car that had this part intact. I have seen masking and duct tape in this location. The parts book says it is rubber.

I fashioned a strip of rubber sheeting that was a pain to attach and keep in place. After 3 years, the rubber sheeting has cracked at the corners and will need to be replaced, so here I am.

The usual suppliers do not have this piece in stock (not a surprise).

I have two questions:

1. Does anyone have a picture of what an original looked like (was it molded like the connectors to the dash outlets, or sheet stock)?

2. What have others done to fabricate this part?

Thank you so much,
Fran

Fran56,
Howdy, I have a couple of projects like yours.

I have not done this myself, but I have heard that you buy an inner tube and cut it to fit the gap. I'm not sure what size of inner tube to buy though. Maybe someone who has done this can give a better explanation of this.

I've never seen an original either but someone said a motorcycle inner tube would work. I believe I made mine out of closed cell foam sheet rubber approx 1/8 thick. It has been many years so can't remember exactly which product but it has held up reasonably well. McMaster has two or three types -- wide in width but available by the foot in 1/8 or 3/16 thickness -- either thickness would work and not be that expensive. I probably ordered a foot and cut a strip approx 3" wide by as long as needed.

IIRC, I used a wood form the size and shape of the sheet metal. Used thin pins or brads to tack the ends of the material over the wood with a bit of overlap and permanently fastened the ends together with brush on urethane or maybe silicone rubber. The seam is hidden on the bottom. Judging from the looks I may have applied the urethane to the entire outside as sort of a finish skin but just can't remember.

Another alternative would be to use the urethane to make the entire piece. Use brushable over a wood or sheetmetal form coated with wax and release agent and do it in several layers to build up thickness. Whether it would last longer is a question but the corners would be formed instead of bent so less likely to crack. Casting urethane as a single finished piece could also be used but making a double sided mold and getting everything else needed would not be cost effective for such a tiny piece.

Here is my blower connection.

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Greetings,
Let the ride decide - I was initially thinking of the inner tube idea, but decided that I wanted something more substantial as a connector if for no other reason than to provide some additional insulation in that area.

Howard - Your solution is the route that I will take. We have a fairly good rubber supply house here in CT that I have successfully used, but if they cannot supply the closed cell sheet rubber it is good to know that McMaster has it.

As to the urethane, did you use "off the shelf" urethane finish (like a Minwax product), or something special to finish and connect the ends?

Thank you both for the replies.
Fran

Two other things,

- Has anyone converted one of these systems from the R12 to a readily available refrigerant? The 2 AC guys that I talked to both discouraged doing that.

- If conversion is discouraged, any ideas where one can purchase R12 refrigerant?

Thanks again,
Fran

Perhaps you know that under the terms of the Montreal Protocol and subsequent ammendments many of the chlorofluorocarbons were banned from import, sale and use except for a very few specific exemptions for some military and medical uses - Freon 12 is among the very worst of the ozone-deleting substances of that class and it was pretty much universally banned in 1996. R-134A was the substitute, so I doubt you'll find it offered legally by any legit commercial source. A conversion will require a change of lubricant oil as the mineral oil used with R-12 is incompatible with R-134A; new seals, hoses and dryer or accumulator may also be needed but all that is well-known, conversions have been going on for 20 years now. All that said I've seen cans of R-12 for sale often at the larger antique auto flea markets - I suspect you'll have to do the charging yourself as any honest service facility will probably refuse to handle it.

Thousands and thousands, more likely tens or even hundred of thousands of old Freon 12 automotive AC systems have been converted to acceptable substitutes so, properly done I don't think there should be any problem.

I used a commercial product from a supply house but that was years ago. Don't remember but it may have been Flexane as that was a product I used on many things back then. If I were to do it again I would use one of the Smooth On brushable productshttps://www.smooth-on.com/product-line/brush-on/ Their Brush On 35A or 40A would be my choice. 35 is at the top end of the soft category and 40 is at lower medium -- roughly equivalent to pencil eraser hardness.

A trial unit contains way more urethane than you would need to seal the seam and give the item a layer or two. It is easy to mix by volume so you can mix what you need and keep the rest -- although it does have a limited shelf life and once opened, even less. You can order online or there may be a showroom for SmoothOn or for the Reynolds Advanced Materials distributorship in your area. Urethane sticks to everything and color may be an issue. IIRC some of SmoothOn urethanes are brownish so you might also need a small bottle of black colorant and probably a mold release agent for the wood or sheetmetal form.

I converted my car to R134A but since my original unit had been molested over the years it wasn't working and parts such as compressor valves and temp control valves are NLA. I cheated by copying and building an entire unit from scratch using all modern components. Put the original on the shelf in case the car is sold and someone wants to spend the money and try to go back to stock.

My compressor and modulator valve were the big issues. Had considered keeping the evaporator and just getting a new Sanden compressor with clutch control for temp adjust. Since the expansion valve and new hoses were also needed and the old unit had flare fittings, I decided to go to all modern with components having O ring fittings and to use barrier hose.

R134 has a much tinier molecule than R12 and will leak in places where R12 won't. There are some who have successfully converted using their original components. With a well thought out approach it can be done. Most of those converted units I suspect have have been on later cars with newer type hoses and fittings etc than our old Packards. Not only are our hoses old but they are made of materials not necessarily impermeable to R134. Flare fittings are another known source of leaks because of the higher pressures with R134 but are not the biggest source of issues.

The old oil is not compatible with R134 so has to change and whether 60 years of the old stuff has permeated thruout the components to the point it can't be completely flushed and will contaminate the new is another unknown or potential issue. There are some oils that are supposed to be able to work with both refrigerants but no idea if they are as good as claimed or if they are compatible with the old oil.

All in all, there are a myriad of issues with converting old units and the reason I suspect your AC guys are not wanting to do it. Fix one compatibility problem and another problem or maybe a leak crops up. It could be more than they want to warranty or tackle. As to finding R12, out here at least it is licensed, only comes in large containers, and can only be purchased and installed thru a licensed shop having the filling and recycling equipment to completely control and account for every last drop used. It is almost a hanging offense for a DIY to have the stuff, not that many don't have left over stuff from the good old days, but just be careful not to get caught.

You might ask your AC guys if there are newer products on the market that can substitute for R134. I seem to recall EPA was on the verge of approving something else but haven't really followed progress after I did mine. At least one poster on site was or is promoting an industrial variant of R12 as an acceptable substitute but whether that is sanctioned or shadetree is unknown.

Here is the unit I built. The flexible foam ducts were cast in molds and made with FoamIt, another SmoothOn product.

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Thank you Dave and Howard....
As always you have provided excellent information which has caused me to re-evaluate the direction I am taking. I did not realize that the R12 was quite the culprit!
For now it will be getting the blower unit back together with the closed cell sheet rubber coated with the Smooth-On A40 for the connector.

Thanks again!
Fran