TPMS

What you run in to is that while driving, centrifugal causes the stems to flex toward the tread of the tire. This can eventually cause the stems to fail.

In my case, my aluminum wheels would not allow a conventional steel valve stem to bolt in. The relief cut into the outside of the rim wasn't big enough for the nut to be bolted in.

I ended up going with conventional pull through valve stems but they were steel. They simply didn't bolt in. Then, I got a short piece of fuel line, cut a slit from end end, and then put the fuel line over the valve stem. This keeps the valve stem from flexing during motion and failing where it seals at the rim.

I think it came to my attention later on that there is a special type of steel valve stem made for such an occasion, but mine has give me several years and 8k trouble free miles.

Our 5th wheel came equipped with metal valve stems, so no problem there with the sensors.

I'm using the TST 507 flow-through sensors on the truck which came with rubber valve stems without any problems to date. When I change out the OEM tires, I'll have metal valve stems installed.

Rusty

I'll also add, some have found they flex enough that they actually make contact with the rim, and rub the paint, etc off...

We've used TST sensors on rubber valve stems and had no issue. Others have said there sensors wouldn't work.

Give it a try and see. If it doesn't work, consider metal stems.

The sensor on the 507 is larger than the others that only monitor pressure I ran mine for a while with out the metal stems but soon as I changed the tires I had metal stems put on.

Absolutely required. I had stems with a metal tube, but a rubber base. I thought that would work. But the forces of that sensor spinning around, finally broke the stem off at the rubber base. Luckily I didn't lose the sensor.

Do yourself a favor, get the metal stems.

Metal stems are required. We had a failure due to the rubber stem over flexing with the 507 flow throughs.

Flow thrus are longer. I would not try using those on rubber stems.

I just put the 507s (not flo thru) on our new 5er. Before ordering the set I emailed with them as the stems that came new were rubber. They said the weight of the sensors would not cause a problem. I had the rig at the tire shop for balancing and asked the cost of having metal stems installed. It was the cost of the stems with only being charged for two dismounts since they only break the bead on one side of the tire/wheel assembly. I went with it for the peace of mind. We are at the half way point of a 3000 mile trip and love the system.

If you carry more than 80 pounds of air in your tires or the tires are over 3 years old, it is recommended you change to metal valve stems. The reason being that rubber valve stems over time and being exposed to heat and cold will harden and get surface cracks. The weight of the sensors will cause a bit of movement and the crack can start to lose air sending out an alarm. That is what happened to us on one of tries that was about 3-1/2 years old so we had metal valve stems installed and have been very happy with them. IF your rubber valve stems are still supple, you may choose to keep the rubber, just then the stems often. Hugs, Di

Colo Native wrote:
I ordered my TST 507 TPMS and it said something about replacing the valve stems with metal one is it rally necessary?