Packard Forum Index » Pre-War (1899-1942)

I rebuilding the thermostat on my 35 1200, I have the bellows, spring and cover. My quest is am I missing any parts? The spring is loose and question if that is correct.I have instructions from Second Chance Garage off the internet which shows a different unit, but have not found any information on the Packard unit-help!!

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I just rebuilt mine also. It is reassembled now, but it looks like you have all the same parts as I do.

I was given a quote by somebody on the upper east coast of $800. It was a short conversation. I opted for a $400 reproduction from Max. I’d like to know if rebuilding it yourself is worth the time given the cost to buy. Do you need special shop equipment?

As of today all you need is an 1/8 inch drill, soldering iron and methyl alcohol,
when I refill the the bellows with alcohol and solder up the hole, I will let you know if it works. The alcohol was a little over $20.

You need only a small amount of methyl alcohol, I used ether and added only 1-2 teaspoons in a 1929 Sylphon. It vaporizes to expand the bellows. Too much might burst the bellows.

You don't say what kind of ether, but that's not the same as methyl alcohol at all.

It was medical ether, I had been told that it was what was originally used in the Sylphon units. Whatever is used today needs to go from liquid to gas, it's that change of state from liquid to gas that expands the bellows.

The hardest part of rebuilding this unit was getting the methyl alcohol inside through the small hole. I injected in with a medical syringe, about 10 drops at a time. With two people, one could pull the unit apart as injecting. Will see if I got enough alcohol into the unit in a few years when I put it back together. Solder up the hole and your go to go. Dell

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"Dell"

A few follow up questions:

1) Presuming the bellows cavity was empty. How much Methyl alcohol volume did you inject through the pinhole?
2) When you tested it thermally, from room temperature to peak 195 deg F (or whatever your peak test temp was), what was the total measured stroke on your units center shaft? (factory manual says 9/16", or 0.5625")
3) At which temperature did you notice the stroke beginning to change perceptibly/dramatically

Many Thanks, Dan

Dan; There was alcohol in the bellows which I drained out. I experimented by injecting an unknown volume of methyl alcohol in, It has the lowest boiling point of the alcohols. I soldered up the hole and heated the unit up and it worked. I keep no records of volume or temperature, just wanted to see if I could get it to work. It will be several years before my 1200 is ready to test it.