Pour a dilute soap solution on the stem before beginning to determine if it's the source of the leak, and repair any leaks by replacing the valve stem core. The process takes about 10 minutes and requires a valve stem tool and replacement core.
- Remove the valve stem cap
The caps protect the stem from mud and dirt. Unscrew the cap, and save it to reinstall later.
- Test for leaks
Pour a small amount of dilute soapy water on the end of the valve stem. If it's leaking it should form bubbles.
- Clean the stem
Use the tapered end of the valve stem tool to remove any debris from the end of the valve stem so that they don't drop into the tire when you remove the stem insert.
- Remove the insert
Use the tool to unscrew the insert and remove it from the valve stem. Air leaks out of the stem when you loosen the insert. Work quickly so that the seal between the tire does not break.
- Insert the replacement part
Use the tool to screw the replacement part into the valve stem. Make sure it's snug, but do not over-tighten.
- Inflate the tire
Use an air compressor to inflate the tire. Use a pressure gauge to check the pressure and ensure it's within the manufacturer's recommended range. Test for leaks.
- Replace the cap
Screw the cap back on the valve stem to provide protection as you drive the vehicle.