Racetrack Post Insert & Poppet, and Liquid Tube Parts Hack

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Feb 3, 2020
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Southeast Michigan
I just picked up a few Racetrack 5 gallon ball lock kegs. They are all Firestones, which I think are the basic early Challenger model. Of course they were old and crusty and needed a thorough cleaning, from which I learned their "anatomy" and unique replacement parts issues.

There are several unique parts (vs the widely available "standard" corny keg parts) in these kegs. This (unfortunately long) post deals with two potential alternatives addressing three of the parts. First is the internal nylon post spacer insert (that acts as a flare style internal post seal) paired with its poppet valve, and the other is the liquid dip tube gasket.

The inserts in my kegs were decrepit (though still providing an effective seal), and one of the dip tube gaskets was stuck solid and got torn taking it out. Turns out these parts are available, but not widely available. I did order a couple of each. The only nylon post insert I found is taller than the one used in my kegs so it has to be shaved down to the right height to work. Based on various forum comments it is a real pain to shave down -- I tried it, and can attest to the difficulty. The replacement dip tube gaskets are fine though. However, I can picture the day when I need one of these unique parts and can't get it quickly (or maybe cost effectively too). So in tinkering with the kegs, I tried a few hacks seeking a stop gap solution if needed some day.

The correct liquid dip tube gasket is like a thick square sided o-ring with a slight recess in one side into which the dip tube flange nestles. It turns out two size 110 o-rings (~3/8" ID, 9/16" OD) stack to nearly the same height as the gasket and are about the same outer diameter. I replaced the gasket with two of these o-rings on two kegs to test the hack. Both have held pressure for several days (one with the original poppet and insert, and one with the poppet/insert hack below).
Dip Tube Gasket 1.jpg
Dip Tube Gasket 2.jpg

The insert/poppet pair was a little more involved. I took a post off of my standard Cornelius brand keg to compare against the racetrack. The Cornelius keg already had its poppets replaced with "universal" poppets - the long spring style that fits both ball and pin lock posts. Comparing the innards of the two posts it sure looked like the universal poppet length was very close to the combined length of the racetrack's insert/poppet pair.
Keg Post Comparison.jpg

Naturally, I tried a universal poppet in a racetrack post and tightened it down. The poppet sealed up just fine, but it did leak profusely from the post base. Without the insert there is no sealing action between the inside of the post and the keg's post mount. Next step was to stuff an o-ring into the post - a standard 111 post o-ring fits right inside the post and around the universal poppet's spring. I tightened this combination down on the keg's post mount and got no signs of a base leak. As noted above, a keg with this conversion in both posts is still holding pressure after several days.

Post with O-ring and Universal 2.jpg
Post wtih Universal and O-ring.jpg

At this point, durability of these hacks is unknown. As long as good dip tube gaskets are available I'll likely keep using them -- but I will put a few 110 o-rings in my spare parts box for emergencies. When I need to replace a poppet and/or an insert spacer I am very tempted to convert to the universal poppet and o-ring. This is about a $2 fix compared to $7-8 per post fix to buy a racetrack poppet and insert, plus the hassle to modify the insert (and risk of ruining it). I probably would put a new o-ring in each time I filled a keg though.

Hope this helps my fellow racetrack keg users.