The other day I heard hissing sound from the front right tire on my van. I noticed that’s from the valve stem of the tire. I pushed the stem to the center of the tire, the hissing disappeared.
I searched online with Youtube, HowStuffWorks and eHow, and it seems that eHow has better information there. Basically, the tire valve stem can go wrong in two ways:
- The core does not work well. Normally, this shows up as slow leak and pressure loss, for example, having to aerate the tire once every month.
- The stem fails as a whole. This is probably my case.
Before proceeding, apply soapy water around the valve stem. If you see growing bubbles, you need to replace the valve core (lucky) or the valve stem (harder). If you don’t see growing bubbles here, you need to check the tire more carefully. Most likely you get a puncture on the tire, or rarely, the rim is damaged and the tire does not fit well with the rim. That is not discussed in this post.
Valve core replacement
If the valve core is the problem, it is easy to handle yourself. What you need is: a) a new valve core; b) a valve core tool. Below is package with both the tool and 4 pieces of cores, sold at Amazon for $4.99:
You can find the 4-pc core set at AutoZone or PepBoys for $1.99 or so.
You need to follow the instructions such as in this eHow article. The important thing to remember: Do NOT remove the core while the tire has a lot of pressure; the bursting core can hurt you. Press the pin in the core to deflate the tire first. It’s recommended to jack the car near the tire before you do this.
Valve stem replacement
As you see above, it’s normally very affordable to DIY for the core replacement, so you can always try that first. If this does not solve the problem, the whole valve stem does not work. For example, due to rubber aging, the valve stem may have cracks, or do not fit the rim hole nicely. You will have to replace the valve stem then.
This is a much more involved work. Since the new valve stem can only be installed from the side of the rim where the tire is installed, you will have to remove or ply away the tire. Then you remove the old valve stem (using some tool and FORCE), and insert the new one into the rim hole (using some lubricant and FORCE). Then you put back the tire and inflate it. To actually do this, you will have to remove the wheel from the car.
It is not very hard to remove the wheel from the car. However, removing the tire from the rim normally require quite some effort, if you don’t have the right powered tool. This is how a garage guy does it: