Replacing tyres on alloy wheels - Sealant?

[jonshepherd]

Somebody told me that when tyres are replaces on alloys they need to be sealed or they leak? Bin to a few tyre garages say they've never heard of it? :S

[JohnW]

You can seal them with a sealant but not necessary. Once the tyre is inflated it 'pops' out onto the outer part of the rim and makes a good seal.

Sometimes on older alloys when they become corroded they can leak which is when the sealant can be used, horrible stuff though.

[chip]

As above, it shouldnt be needed, all they normally put on is a soapy lubricant that washes off.

[Mark T]

the sealant is used where the lacquer is flaking off

[dafz]

Sealant may also be needed if you want to stretch low profile tyres onto deep dish / wide wheels (euro style).