Always check other people's work
 

My 15x9 6ULs currently have Hankook RS-4s mounted, which are great when up to temp but are treacherous on a cold and rainy day. I decided to put more rain-capable tires on my other set of 15x8s, initially going to go with RA-1s but being talked into the newer R888R. They came in a couple of days ago, just in time for our first track day of the season (which is also going to be cold and wet). I dropped the loose wheels off on Wednesday and picked them up the next morning. I still had a bit of clean-up to do after botching my 100,000 km service, an oil change to perform and to switch to the new rubber. After everything was buttoned up, it was time to adjust tire pressures. The first two wheels were fine but when I got to the third one, loosening the valve cap resulted in a cacophonous whooshing of air. Tightening the cap stemmed the leak but loosening resulted in more of the same. Long story short - three out of four wheels were missing the valve insert in one of the metal valve stems. It was blind chance that I discovered it, as I could quite easily have gone to the track with only the valve cap keeping pressure in the tire. It's obviously a relatively air-tight valve cap, but still...

Obviously whoever dismounted the last set of tires (probably the previous owner or his proxy) pulled the insert to deflate the tires, didn't bother to replace it but did screw the cap back on. My tire shop, who are usually quite reliable, didn't think to check as they rarely see wheels with dual valve stems on the same side of the wheel, plus it was holding pressure just fine. Anyway, something to double-check whenever you do a tire change-over.

P.S. Also remember to take a deep socket and snug up the 6UL metal valve stems. I generally find them on the loose side after a change-over, which I found out to my chagrin after a mysterious air leak during a previous track day,

Meh. If you catch your dick in the zipper of your pants after using the restroom, I don't know if I would describe the experience as "The dangers of pants". It's more the danger of not being careful, or in this case, being downright negligent/malicious.

I throw those little valve stem caps away the moment I install the stem. They are meant for street cars which get their tires serviced every 5,000 miles, not track cars which get pressures checked every 30-40 miles. That would also solve this issue entirely.

Geez Andrew, I was just having a little fun with the title - you know, hyperbole. Obviously, having dual valve stems isn't inherently dangerous but I thought my anecdote might, at worst, be passingly amusing and, at best, might cause someone in the future to check something they might not otherwise think to check. Any yes, I remove a valve cap (singular) on my track wheels for the reason you mention. I just do it to one as I figure the other might help keep dirt out of the needle valve.

Maybe re-title "The Danger of Tire Shops"? :rofl:

Yesterday I was having some tires mounted up for our ZL1... staggered fitment, and of course they managed to put a rear tire on a front rim and vice versa.

ALWAYS check the work of tire monkeys... in fact, I always check the work of anyone working on my cars, including myself! :p

I am just poking fun. Putting a valve stem cap back on without a valve core in the stem is really, really dumb. I would never even think to check it, but I also trust my tire guy a little more than that (I have a guy, not a shop)

I leave both caps off because I like to pick whichever stem is furthest from the ground, but I suppose it also prevents stuff like this.

Unfortunately, that isn't how the internet works. Your thread title will generate phone calls, emails, facebook posts and new thread on other forums debating the idea of dual valves because of the "inherent danger" which does not actually exist.

Think I'm over reacting? I would invite you to sit in my chair for a week before finalizing that opinion. If you are a fan of what we do here, I would kindly ask that you edit your thread title to something less click bait-y like "Dangers of not checking your valves" or perhaps "Dangers of bad tire shops"..

And yes, we also recommend retorquing any threaded valves (any brand or material) each time new tires are mounted.
As Andrew offered, we never install caps on track wheels. Not needed and they just get in the way of things.

That said, it's a valuable PSA. Thanks for that.

Fair enough Emilio. I went to edit my post but it doesn't seem to allow me to edit the title. Could perhaps a moderator do it? Who should I ping? Title could perhaps be "Always check other people's work".

Done.

Thanks Joe.

Exactly the reason why I'm on the hunt for my own personal tire machine. I have a good tire guy currently, but he is extremely busy and scheduling is a hassle. It's also hard to justify getting him to take his time on a set of track wheels when he could be spending his time making big money doing diagnostic work.

Definitely wise to check after anyone that touches/works on any car, even daily drivers. Just last month I bought my wife a new car and the finance guy was mad that I wasn't going to sign a service agreement with the dealership. Right on cue a customer came in complaining that his oil had been over filled by the dealer by two quarts. One glance at the finance guy after we both heard the complaint and he didn't mention the service agreement again haha.

I’m probably late to the game, but why run two valve stems? I googled it but the answers were mostly posted by riceboi vapetards who think it looks cool for some reason. Is just it a convenience thing, or is there some other purpose?

Nitrogen purging.

What he said.

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The thread title change was fortuitous, as I ran into another shop-related oversight today at the track. The independent that troubleshooted my oil leak forgot to tighten the 14 mm bolt behind the power steering pump pulley. Consequently, I lost the belt at the start of one of my sessions. Luckily it landed, intact, on the undertray and I was able to retrieve it in pit lane. Reinstallation was a snap and I was back out soon after. Unfortunately, that session was cut short because of a high-rpm engine miss (I'll start another thread about that). I lost the same belt (shredded that time) a couple of years ago for exactly the same reason - also due to a shop's oversight.

On a more happy note, I was very happy with the Toyo R888Rs today. The temperature was just above freezing, as in a couple of degrees at most. The track surface was cold due to a recent snowfall and the only thing it had going for it was that it was dry. The tires handled the conditions really well, inspiring confidence even on the out-lap. I took it easy for the first session to allow the mould-release compound to work its way out but they performed very well once pushed.

Those caps are annoying especially when checking tire pressures between sessions.

https://cimg6.ibsrv.net/gimg/www.mia...9edb528f7f.jpg

Yep, I've had Discount Tire monkeys mount directional tires that gave me 3 rights and 1 left more than once. Don't trust them to do it right.

Discount Tire: We do it right because we do it twice!

In addition to the N2 reason above, I've had issues getting beads to seat on some tires (used SM7's on my 9's) and if you don't have a bead blaster (or its shitty on your tire machine) the second valve helps with air addition to get the initial seat started.