Hello! We have a 2008 Toyota Prius and we just got 4 new tires put on February 28th, 2012, but we didn't go to the local dealer. It has been one month, and last night we had a flat. Took it in today to the shop where we purchased the tires and they said the service pack was faulty and they put a new one in. I filled the other three tires up this morning because they seem to have been losing air as well. They were all down to 20 psi, and the tires say 44 psi on them. Do you think all service packs were faulty? Could the tires be mounted on the wheels incorrectly? I always though that the inside edge of the tire and the outer edger of the rim were flush before, but the tire is mounted so that about 1/8" of rim is out as a "lip", of sorts, on all four tires. Also, TPMS rebuild kits were NOT installed. The shop said it wasn't necessary. They just said each tire needed a $3.00 service pack as opposed to a $30.00 TPMS rebuild kit, which they don't do anyway. I am thinking that maybe we need to take it in to the Toyota dealer and have them look at the tires just to make sure everything is installed correctly. Does anyone have an comments or suggestions? Thanks!
Before doing anything you should start by actually measuring the pressure before and after driving for a week or two, rather than just assuming that the original tire pressures were correct. Try to fill/test the tires when they're cold to minimize errors due to heating.
Something sounds very screwy here -- Are you sure the tire size is correct for your rims? The "44" that you refer to is the "maximum" pressure for the tire. Did you go to a "tire shop" - if so, they SHOULD know what they're doing. There is no way that you should have one flat tire and 3 down to 20 psi --- IF the tire shop knew what they were doing.????
The rims could be corroded causing a slow leak at the bead. That would require taking the tires back off, cleaning up the corrosion, using some sealant on the beads and reinstalling/rebalancing your tires. JeffD