Just a question........

[Zrider]

I had a tire puncture last spring, and when the dealership went to patch the tire, they found that the metal aftermarket valve stem cap fused to the valve stem and had to be cut off and the TPMS sensor replaced. I checked the other tires and found the same thing had happened to two of the other tires and I had to do the same two those 2. Anyone else have had this happen before?

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[Grumpaw]

Have seen that many times, especially if the cap was aluminum. Over time different metals can react with each other, resulting in what happened to you. Thats why you will almost always see the plastic type caps as OE.
In areas where roads are treated the "welding" can occur in as little as a few weeks.
Go back to using plastic caps....

 

[Zrider]

Have seen that many times, especially if the cap was aluminum. Over time different metals can react with each other, resulting in what happened to you. Thats why you will almost always see the plastic type caps as OE.
In areas where roads are treated the "welding" can occur in as little as a few weeks.
Go back to using plastic caps....

Yea, that's what I did, went back to the plastic caps. Still have some nice orange ones that came with another item I bought for my Ranger, but wasn't going to make the same mistake twice.

 

[Grumpaw]

Aluminum is pretty much the worst when it comes to reacting with another metal, especially if the part is not coated.
It's why you will see very little in aluminum or alloy parts used around marine applications, especially where salt is present....it only takes a few days for aluminum to "weld" itself to another piece of metal, ruining both.

If you can find caps you like made with stainless steel or plated brass, they will be fine.

 

[OrangeStreak]

Aluminum is pretty much the worst when it comes to reacting with another metal, especially if the part is not coated.
It's why you will see very little in aluminum or alloy parts used around marine applications, especially where salt is present....it only takes a few days for aluminum to "weld" itself to another piece of metal, ruining both.

If you can find caps you like made with stainless steel or plated brass, they will be fine.

Right about aluminum material...even though it conducts electricity very well, if it is connected to some dissimilar materials or receptacle's that are designed for copper it can also create a fire hazard. We bought a home one time which we discovered had aluminum wiring but were not informed about it prior to the purchase. One of the fixes for this is to have special cooper fittings pigtailed over the aluminum ends at all the electrical connections.

https://www.schaferelectric.com/dangers-of-aluminum-wiring/

 

[TJC]

That aluminum wire would oxidize and loosen (Different expansion coefficients) from the copper / brass screw, causing resistance to climb, resulting in excessive heat. I've seen 110V receptacles crumble in my hand from extreme heat caused by aluminum wiring loosening at the copper contact point. First symptom was lights flickering that were plugged into the wall receptacle. If you wait too long or don't discover them, you are at risk of the house catching fire.

I don't use disparate metals in my truck or car cooling system either. Electrolysis is a real problem, and will cause rapid corrosive issues, not to mention stray electrical currents.

 

[P-38Ranger]

But remember the stem Schrader valve is not the primary method of holding air in your tire. The valve cap, one with a proper O-ring is the primary method of holding air in a tire.
Now I have to go out and check my bright red aluminum caps.

 

[Grumpaw]

But remember the stem Schrader valve is not the primary method of holding air in your tire. The valve cap, one with a proper O-ring is the primary method of holding air in a tire.
Now I have to go out and check my bright red aluminum caps.

In reality the schrader valve is the primary method of sealing the stem via the small spring loaded post. The OE plastic caps do not have any O-ring. You can run a valve without any cap and not loose any air, but that leaves the valve open to dirt/grit getting in the valve.
Also, after a period of time the O-rings in the aftermarket caps can deteriorate, dry rot, and become very small pieces that can get under the sealing post of the valve, causing it to leak.

 

[Stevedbvik1]

I put anti seize on mine about a month ago. I guess it’s time to check them. ?. I hope that I’m not relegated to only using them for festive occasions.

 

[skrumpe]

But remember the stem Schrader valve is not the primary method of holding air in your tire. The valve cap, one with a proper O-ring is the primary method of holding air in a tire.
Now I have to go out and check my bright red aluminum caps.

If that were the case, my ac wouldn't have lost freon in the minivan I owned years ago. Tightened the valve and leak gone.

 

[skrumpe]

I put anti seize on mine about a month ago. I guess it’s time to check them. ?. I hope that I’m not relegated to only using them for festive occasions.

That's where my mind went. Wouldn't anti-seize help prevent this?

 

[Msfitoy]

I use these captive metal caps...not sure what they're made of but they've never been lost or welded themselves to the stem...

 

[moorejl57]

But remember the stem Schrader valve is not the primary method of holding air in your tire. The valve cap, one with a proper O-ring is the primary method of holding air in a tire.
Now I have to go out and check my bright red aluminum caps.

You must be a HVAC guy. I just did a service on my R22 heat pump and all three Shrader's were leaking. Got the stem removal tool and replaced them as well as new brass caps with O-rings.

 

[Grumpaw]

I got in the habit of checking the stems every few months. Simple $2 buck tool. What got me in the habit was a period when we had a class a motor home......tires were 80 psi and it was not uncommon for a stem to back off occasionally. Just as little as 1/2 a turn can lead to a leak.
Our current camper has a 65 psi cold fill, and has sensors on each tire....but the part of the sensor that contacts the valve is also made of brass....so no "welding".
Just check the stems twice a year, use plastic caps, and all problems will be avoided.

 

[Stevedbvik1]

I got in the habit of checking the stems every few months. Simple $2 buck tool. What got me in the habit was a period when we had a class a motor home......tires were 80 psi and it was not uncommon for a stem to back off occasionally. Just as little as 1/2 a turn can lead to a leak.
Our current camper has a 65 psi cold fill, and has sensors on each tire....but the part of the sensor that contacts the valve is also made of brass....so no "welding".
Just check the stems twice a year, use plastic caps, and all problems will be avoided.

But nobody makes a plastic Sasquatch valve stem cap ?‍. “ It’s a simple CAD exercise “ ?

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