Slow leak from tyre on alloy wheel

No, they are varnished, well, most are.If they werent, then the ally would corrode quite quickly. I had a similar thing, new tyre fitted, was flat the next morning, they said the same, the bead where the tyre sits was a little corroded, it needed to be filed flat, as the corrosion was too rough to just sandpaper it down, the easiest solution was to daub some puncture glue around the rim bead, then fit the tyre. It worked, though no doubt would make a mess whent hetyre was removed again. Alan.

They are lacquered to stop them going furry. It is not bullshit. If you take it to National Tyres they will most likely simply sand/file it as required and refit your tyre for about £5 ~ £10. That's what they did for me.

No. At the very least, they're laquered. Pretty much every manufacturers alloy is painted.

They are correct. Wire brushing the rim on its own just doesn't work as IIRC at least some alloys are porous. It needs to be painted.

[snip wise advice]

Ta muchly, you live and learn. Strange that the tyres on my '64 Morris and '84 Bedford never lose pressure from their old steel wheels but our newest car (wife's Rover) has always been a pain in this regard.

Can you still get pressure indicating valve caps which would at least make it trivially easy to keep a check on any pressure loss? I have such a thing on inaccessible spare wheels but a set for the main wheels would be useful.

Peter

Yes, there are various makes available. There is a small review of some here:

I have found in the past that with any type of wheel, slow pressure loss seems to reduce after the tyre has been in place for a few weeks. I've had this happen after a puncture repair; the tyre still lost several pounds a week. After a month or so it didn't lose any significant amount, so perhaps yours will settle down.

Chris

bead sealant and all tyre shops will have this.

Laquer will chip away and allow road salt to start the oxidation process (worst alloys are those with a laquered natural finish)

If you suffer this issue its important not to drive at any speed, could pullaway from the rim and deflate quickly

On one of my old cars, I had my alloys blasted and powder coat at £110 for all 4 (a couple of years ago now). Looked like new and it of course stopped any potential problems with air loss from the tyres.

Cheers Paul, Wakefield

Had the same problems on a 10year old toyota supra after I changed the wheels. The alloys do this as they get older. Solution take it to a garage and ask them to take the tyre off clean (air powered wire brush) and lacquer the wheel rims) then replace the tyre. My garaged charged me only =A310 a tyre which was pretty good since they rebalanced it as well. I'd be tempted to try this tyre sealing stuff next time. You can get it from most accessory shops about =A310 for a bottle. You removed the valve swirt it in and replace the valve cap and inflate. It is supposed to stop punctions so might just fix it around the rim as well.