Breaking Valve Stems - Mazda 3

Hi folks,

Had a valve stem blow out of a tire on the highway last week. Second time that’s happened on my 2009 Mazda 3. Broke off stems two other times while putting air in the tire, those cost me $150 each to replace. This just happening to me … the mechanic handed me the last valve that blew and said it looked like it was corroded

I am wondering why it cost $150 to replace a valve stem that blew out when putting air in a tire? I would have all the valve stems replaced with good quality ones, they make metal ones for trucks.

Trouble is, simple valve stems are much too cheap and simple to satisfy the government. We now have expensive, difficult to access (have to remove tire from rim), and irreparable tire pressure sensors instead. Thanks lazy americans and government safety nazis.

But even my Ford valve stem mounted sensors have replacemant valve STEMS available for sale.
Wonder why mj133 is being slammed for sensors every time ?

We own a 2010 Mazda3 and the valve stem is right where they always are. I’ve never seen a wheel you had to remove to access the valve stem.

Hokie, you cannot replace a valve without dismounting the wheel from the car.

However, you CAN replace a valve STEM without removing the wheel. Just unscrew it from the valvebody. But I truely think the OP is referring to the entire valve.

If the valve stems are made of aluminum these are prone to breaking off in the areas where salt is used on the roads in the winter.

See if there are aftermarket tire pressure monitor sensors for your vehicle that use rubber valve stems.


The same, I think you are thinking about the valve “core” which screws into the valve “stem”. If you have a TPMS valve stem and it breaks off, I think you are forced to replace the whole TPMS valve and sensor for that wheel from inside the wheel.

Guys, I guarantee you 100% this car has TPMS

That gets pretty expensive when you break the valve stem

If you broke a TPMS valve stem, the smart mechanic would replace the entire thing (sensor AND valve stem)

Then you have to reinitialize the TPMS system. Sometimes you need a scanner to enter learn mode. Sometimes you even have to use the scanner to manually enter the new sensor’s ID.

GM and Ford is relatively easy . . . no scanner required. Toyota is a major PITA. I’m not sure about Mazda.


" . . . you CAN replace a valve STEM without removing the wheel. Just unscrew it from the valvebody."

Sounds like you’re actually talking about the valve core . . . ?

As others have stated, what’s breaking isn’t a valve stem but rather the tire pressure sensor. If you live where rust and corrosion can be an issue on cars then it’s possible that that’s the problem.

Do you still have the original wheels and tires? If you have had wheel or tire service done it’s possible that the sensors were removed and remounted and not torqued properly. There is a torque spec for these.

Also if the tires were inflated from a compressor that wasn’t properly maintained and has a water separator, galvanic corrosion could have damaged the sensor.

BTW, $150 is a pretty fair price for a new sensor, mount and balance of a tire, and programming.