Hello

My Front and Rear right hand wheels are annoying me because they slowly deflate after a random period of time.
Say I pumped them up to 31 PSI to match the other 2 left hand wheels. Within about 1 week and a half I need to re-pump them as they sometimes reach as low as 15 PSI depending on the usage in that time period.

Now I have been to a local tyre dealer and they have told me that it is my steel rims. They are abit rusty and the bloke says rusty rims can cause slow deflation.
Is this true?

I'm assuming that this is not a punture even though I have been told it wasn't one.
Because puntures more or less deflate the tyre alot faster, right?

I've checked each tyre for visible nails etc, but nothing.

Anyone got any ideas? 2 new rims or 2 new tyres?

Thanks