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

Hello!

I'd like to repair the gas gauge on a 726 back to its original functionality. My understanding is that the bromide that fills the gauge eats at the potmetal unit it is contained in until, as my grandfather describes it, the fluid starts to leak out onto your shoes.

I understand that replacement parts for these are readily available at Classic and Exotic Service, Inc., and they look to be made of brass. They also sell the fluid to fill the gauges. How do those parts hold up over time? Do these gauges inevitably break again?

I doubt there is much useful data out there about the lifetime expectancy with new brass parts but with the original diecast parts the working life of the unit seems to be about 50 years, + or -.

I do not believe any chemical is responsible for the disintegration of the fuel gauge unit, the fluid travels in a copper tube from the tank and ends up in a glass tube in the gauge face. The unit itself is made of pot metal and over time it swells and then crumbles. Door handles on 7th series and other early cars suffer the same fate and they're not exposed to chemicals. Cars were not engineered to last 90 years.

This post has additional details on the gauge. The original gauge fluid is acetylene tertabromide.

Very dense liquid, almost 3x that of water.

Reacts with most metals, see MSDS for more info.

https://www.spectrumchemical.com/MSDS/T3180.PDF

https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=6512&viewmode=flat&order=ASC&type=&mode=0&start=0

Thank you! That's very helpful.