99 forester ...Getting ready to change back to summer tires and when I went to check them I found they had all leaked down over the winter 2 had no pressure, 1 had 10lbs and 1 had 15lbs, I understand that this can be a problem with alloy wheels as I was topping them up about every 3-4 weeks during the summer but this is the first year that i ran snows on the car so they sat all winter. Should i look at having the tires taken off and rims cleaned up before reinstalling them and if i do that is there anything else i should have done...new valve stems??? thanks

There are various sealers that can be put on the rim before the tire is mounted. I asked for it when I had tires put on my Audi, they didn't do it, I've been back four times with leaky tires needing sealant put on the rim. It seems to help with the corrosion from salt getting trapped in between the rim and rubber.

Thanks...I will definately make sure to insist that they use sealer when reinstalling the tires..

There are various sealers that can be put on the rim before the tire is mounted. I asked for it when I had tires put on my Audi, they didn't do it, I've been back four times with leaky tires needing sealant put on the rim. It seems to help with the corrosion from salt getting trapped in between the rim and rubber.