Hi My sons car has alloy wheels, and metal valve stems, there is a tiny leak between the valve stam and the alloy on one wheel, we are struggling to get anyone to repair at a reasonable cost. Would tyre weld make a permanent repair?. Some tyre specialists won't touch the wheel, one other wants to drill out the stem put in another, which sounds a bit drastic. Any other ideas?, is it feasible to get the metal valve stem replaced by a rubber version?. Apparently the metal ones get curbed and then start to leak.
On that year car the tire is tubeless and the valve stem should not be moving as it would if you had a tube type tire. If the valve stem is pushing in it means you drove on the tire while flat and probably ruined the tire as well as the valve stem. The tire must come off the rim to be inspected before blowing it back up and used. If you don't inspect the tire it will probably blow out at highway speeds and kill someone!
The leak is caused by corrosion of the alloy wheel in the hole that the metal valve stem goes through. You might try to let the air out and loosen the nut on the valve stem and spray penetrating oil on the o-ring which is on the base of the valve stem and is what holds the air in. Turn the stem back and forth a bit to mave the corrosion and then respray the o-ring. Tighten the stem nut, inflate the tire to 35 lbs. and spray a bit of soapy water on the stem to check for leaks. If it still leaks you will need to remove the tire and valve stem,clean the hole and surrounding area inside the rim and clean the valve stem and replace the o-ring. If the valve stem is a pressure sensor type for the tire air pressure monitoring system you may need to reprogram it. Only use plastic caps on the valve stem. Metal ones corrode on the stem and wreck them and never come off.
