2017-07-14

Repairing a Tire Valve Stem

We were on our way through Leadville and decided to take a look around town. As we walked away from the car I looked back and realized our right front tire was mostly flat! I'd noticed funny handling on the road, but thought maybe it was my imagination or the rain, or something else. Stupidly, I hadn't stopped.

Anyway, on closer inspection the tip of the valve stem (where the cap screws on) had been crushed and shattered. We decided maybe we should swing by a shop, it was late but *maybe* they'd be open. We pulled in to a shop AS it was closing. The two guys there were really sweet though, and fiddling around managed to put some more air in the tire so we could be on our way.


Next day, first thing after breakfast I took a look. Tire was flatter than I wanted to drive on, and when I poked the stem I realized it wasn't just the tip, the base was cracked and split clean open. Aaaalright then. I quickly swapped to the spare, and we drove in to town.


I've been thinking that I should really try more repairs than I've been attempting, and this was a good opportunity, so we went down to O'Rielly's. After a search on Google I found I needed a "Valve stem puller" tool. I found one in the shop which was also a core removal tool, and tire deflator, great. I asked the clerk how to tell which valve stem to get, she said she didn't know, so I figured I'd just pull it and compare visually.

The plan was to pop the tire inwards off the rim, unseating it on one side, pull the valve, and pop the new one in from the backside, then reseat the tire.

I pulled the stem straight out actually, turns out you can just pull sideways and work at it and it'll come out eventually. There wasn't a lot of thread left, but enough to make that work.

Next we tried to break the bead. First I tried hitting it with a hammer (backside of an axe actually), as suggested on various websites, but that didn't work. I tried combining that with a tire iron (the one on the back-side of the lug-wrench that came with the truck). No luck. A guy stopped and suggested we go across the road to a shop and get them to break the bead, but I wanted to do it myself.

Next I tried a bottle-jack against the bumper, but the jack ran out of length before it popped the bead. Then, Angie suggested (based on an internet search), driving over the tire... It sounded like a good idea.

I threw the truck in 4L and Angie aligned the tire. First attempt I ended up on the rim, but the second try popped the bead right off! Great! Now we could slip the new valve stem in to the hole, screw on the puller, and with a quick pull pop it in to place.

Now comes what is generally considered the hardest part, and the reason you "can't do this at home"... reseating the tire. You have to get the bead close enough to the rim that it'll hold air until the air pressure builds up and pops the bead on. There are a couple of tricks for this, but the best known (explosions), isn't terribly safe. I'd read of a trick a while back where you surround the tire with a ratchet-strap and crank it down. This helps push that bead against the rim... So we gave that a try.




Aaaand, magic, it seated right on! Of course, now there's pressure in the tire, and you have to break the ratchet-strap free...

We ran the pressure up to what our crappy compressor could handle (enough to drive for sure), but the compressor started making kind of awful noises so we finished at a nearby gas station.... and off we went!

Seriously, if you can change a tire, this is only a bit harder. Tools needed (besides the normal tire-change tools):
  • Valve stem puller ($5 from O'rielly's)
  • Spare valve stem ($3 from O'rielly's)
  • 12v air compressor (~$25 from Amazon, but you should have one anyway)
  • Ratchet strap (~$10 from any hardware store, but you probably have one, a rope with creative knot work should work as well)
  • Car that can drive a little (probably using the spare)

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