valve stem caps
- Thread starter fxrider
- Start date
I believe it because last year my G35 caps were almost siezed on the stems from the corrosion caused from salt used on the icy roads
santiagodraco
Member
- Location
- Austin, TX
- Car
- 2010 FX 50s
But your old caps sure look nice on the mechanics ride! 
- Location
- Westchester, New York
- Car
- 09 FX50
it doesnt make a difference mine are always metal and are fine (bought off of ebay, too)
Ha, the TPMS sensor is inside the wheel. The valve stem is indeed part of the sensor though.
As long as you use a cap, you are fine. In regards to the plastic one being better? It won't seize and rust in salt if you had cheap caps which many are.
I have aluminzied steel ones that last a while. It's more for looks so take your pick, they are like $2 for 4.
- Location
- brooklyn, ny
there is a difference with tpms, & yeah, the wrong caps will corrode & lock on there... also ther valve core has to be specifically for tpms too, even though standard cores will fit there are some metalurgical compatabilty things going on there... forgot the specifics tbh...
Here's the quick and dirty from an electrical standpoint. Different types of metal sandwiched together actually forms a weak electrical current. That is, a very small electrical charge flows from one metal to the other. This charge is one of the things that oxygen needs to form rust - which is the oxidation of the surfaces of the two touching metals. Salt can also play into the chemical equation, making oxidation even easier. In this case your valve stem and the cap are the two dissimilar metals.
You can combat this with non-conductive protection like paint or you can use a non-conductive metal like zinc or nickel. You can also use oil, which inhibits oxidation by not allowing air (oxygen) to come into contact with the metal surfaces.
I use chrome caps with rubber o-rings and have never had any rust problems. Chrome is the metal in Stainless Steel that provides most of the corrosion resistance. There's some nickel in there too.
You can combat this with non-conductive protection like paint or you can use a non-conductive metal like zinc or nickel. You can also use oil, which inhibits oxidation by not allowing air (oxygen) to come into contact with the metal surfaces.
I use chrome caps with rubber o-rings and have never had any rust problems. Chrome is the metal in Stainless Steel that provides most of the corrosion resistance. There's some nickel in there too.
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