A few months ago one of my fronts tyres started losing pressure, after a while I took it for repair. He said there was nothing wrong with the tyre but it is the alloy wheel, he then got a grinding wheel on the rims and said that should sort it out. Apparently they grind all alloys that they get whether it is a new car or old.

Looking back I don't think that grinding the rims was a good thing and also the pressure still drops. Any ideas on what is causing the leakage?

Corrosion on the inside of the rim is the usual culprit and the tyre fitter would be right. Grinding the inside of the rim should only be done if there is corrosion present. The valve can also leak usually because of corrosion too hence why they fit new ones. 

The well of the wheel can become porous too which normally requires a refurb to sort properly. 

In the past I've used Holts Tyre Weld to seal leaking wheels. If you do this let the air out of the wheel before applying. 

On ‎19‎/‎06‎/‎2017 at 20:39, CWARD said:

Corrosion on the inside of the rim is the usual culprit and the tyre fitter would be right. Grinding the inside of the rim should only be done if there is corrosion present. The valve can also leak usually because of corrosion too hence why they fit new ones. 

The well of the wheel can become porous too which normally requires a refurb to sort properly. 

In the past I've used Holts Tyre Weld to seal leaking wheels. If you do this let the air out of the wheel before applying. 

ive got the same problem with my Leon 16" and Volvo T5R 17" alloys. on the Leon the tyre weld seems to hold, seems leaking out of the base of the valve, when you wash them check for bubbles. the Volvo on the other hand leaks round the rim, I need to get them refurbed again, tyre weld only works for so long. so Ive ended up using slime in those, it can cause balance issues though.

 

my dear old Dad likes steels wheels because of all the hassle you get with alloys.

Cypher, on the Volvo if you remove the leaky wheels, let the air out and use G-clamps to pull the tyre bead away from the rim. You can then go round with a wire brush to remove the bulk of the corrosion then use some 400 grit wet and dry to clean then up. When you inflate the tyre it will be air tight again.

 

My tyre fitter has ground both of my front wheels and given the insides of the wheels a coat of some black jack stuff, no probs since

^^^ All the above, clean rims / beads, even use black sealer, and when still losing pressure let the air out and put half a can of tyre weld in each tyre then get the tyres pumped up and run it.

Desperate measure but usually works.  Tyre Weld, or what ever is cheap that does the same job for puncture repairs can seal the beads for long time mister.