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Advice on replacing valve stems – (Alcoa wheels)
We have had a valve stem failure on a
tag axle wheel (after a Love’s truck stop tire pressure check). (Fortunately, it appears to have been a slow
leak, as we were only an hour from home, and the flat did not show up until
several days after getting home.)As we go about selecting a
replacement valve stem for this failed one (broken off just past Schraeder
valve),
we are wondering about the collective wisdom from the group on the proper
choice(s).As we look at all the tires, even though all of the tire
valve stems were supposed to
have been changed when the new tires were put on (as part of the original
purchase zeroing out maintenance), apparently they were not (as there is a mis-match among all of the various
wheels.) So, we plan on replacing all of
the valve stems when next we get the opportunity, but want to purchase all of
them now so as to have correct/matching valve stems for that swap.Is there a preferred brand, or should we just find what
is the most common at truck stops to give greatest chance of having spares
available in the event of an emergency?
Thanks! -
17 Replies
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Mike,
Because the extensions are brass we naturally assume they are good for the life of the coach. But may years ago Prevost made it clear the centrifugal force as we roll down the highway stresses the tire valve stem at the bend, and this is especially true if you use extensions or when checking pressures you try to flex the valve stem a little.
But we not only do have valve stem failures, a very common problem is a leak because the rubber seal between the stem and wheel ages.
Replacing them is cheap insurance. Don’t tell Tom, but when I change my tires I am likely going to use Pressure Pro and have valve stem extensions as soon as I have figured a support to prevent flexing. I might change valve stems when the sensors need new batteries because even though it is not much weight, it does add a little more stress.
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Thanks, Jon.
That’s a good reminder: we will look at replacing and adding TPMS sensors with the change-out of the valve stems.
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Can the valve stems be replaced while the wheels and tires are on the coach? Or do the wheels/tires have to be removed? Do the tires have to be dismounted or the beads at least broken?
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Dick,
I think that, at a minimum, the bead must be broken to get to the valve stems.
It makes me wonder about / consider the internal TPMS systems…
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I had a slow leak on one of my inside drive tires and thought it was the valve stem. It was. Changed it out for a new brass one for $25. Cheap insurance. They had to remove the the tire, break the bead and remove & insert the new valve stem. Had I thought about it, I would have changed out the other three drive tires. Next time I have some time at a Love’s Truck Store, I’ll probably get it done, but the Pressure Pro System certainly helps in evaluating slow leaks vs. taking out your tire gauge all the time.
My steer/tag valve stems are new, since I put new wheels & tires on them (365s), but for some reason, when they put new tires on the drives (315s), they failed to put new valve stems. Had I known about it then, I would have insisted they put new valve stems on them. Hindsight is 20/20 …
Also, I removed both 4″ valve stem extensions, since they are a source of many leaks, and most “truckers” won’t use them since they’re not as reliable.
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Tim: If you removed the 4″ extension on the inside duals, what do you have left? Just a little valve stem sticking out? How do you check it and put air in? I wasn’t a trucker in any previous life, so all of this is new to me.
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Dick, It’s no problem checking/filling the inside tire since I Have both a 7″ & 14″ tire chuck mounted on my air hose connected to the coach. I’ve noted my pressure pro sensor usually measures 2psi less than the actual psi when I use my digital tire gauge. The “trick” really is using the PVC “wrench” for the PP sensor to remove & re-attach in the valve stem. I got that idea from Tom. With a little practice, you can get it done pretty quickly.
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Hell may have actually froze over!
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It hasn’t happened yet, but it is getting chilly down there.
I am still really having a hard time coming to grips with the loss of a double seal.
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My last go around with leaking valve cores, I had all tires unmounted, vacuumed out and all new valve stems/cores installed. For the inside drive tire we discussed extensions. Both myself and the tire store were in agreement not to use them, so the discussion was very short. They installed longer stems that put them just inside the outside rim.
This is fine as I have TPMS valve caps. My valve caps are actually hexagon shaped so I use a socket on an extension to remove/install the caps when needed. The outside valve stems I had installed pointing at a 90 degree angle to the face of the rim allowing easy access to the valve cap/TPMS sensor (i had them pointing inward, making it a little hard due to space to get to the valve caps/TMPS Sensors.
Even with all brand new stems/cores I still found one core that failed after 6 months of being installed. The valve cap is acting as a seal, so no air leaks past that cap. But when I remove the cap, I can hear the leak. Keeping the cap on will allow me the time to get it to a Loves and get the core replaced (don’t want to do it here as I don’t have the air system to set a bead in the event I let too much air out and break the bead).
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I had this happen to me this past summer – I always check tire pressures at my pretrip each day so I know the tire had air when I started but I don’t check them when I get home. So a couple days past and I noted at my next pretrip inspection a tire at ZERO PSI. I took in into the tire dealer to pull the tire off the rim (and find the leak – which truned out to be a bad valve stem). I had the inside of the tire inspected by the tire dealer just to make sure they did not see any damage (just in case the leak happeded during operation). I can see the value of a TPM system so you know what’s going on during the trip. In this case, I had no idea if I ran the tire low (and caused any associated damage to the tire) without a close inspection.
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Quite often a leak at the valve stem is the Schrader valve no seating for any number of reasons. I caary spares, but before I do anything I give the tire a good shot of air. As long as there is a decent pressure differential between the air hose and the tire, if the issue was just something getting in the valve seat the air flow usually blows it out and I am good to go.
With the double seal caps I just do not have that issue any more.
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Charles: Can you post a picture of what you have? Thanks.
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Jon: Since hell is about to freeze over and you are concerned about losing the double seal I have the solution for both you and Tom. The quickest and best solution for you would be to trade up a couple of years, get the Prevost internal tire pressure system and keep your double seal. That would give you the opportunity to earn Nancy’s admiration for life, satisfying her longing for a double slide coach by letting Tom have first shot at your older coach which he could then sell himself another set of TPM, make a little profit, and all of you would be happy and benefited.
Absolutely no charge for this advice. Just being helpful amongst friends.
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Please…. You non Pressure Pro guys are are riding on a time bomb..
Seal concerns, excellent fuel for Jon’s garden.
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