Use grease on alloy caps to prevent a chemical reaction.

Smearing the brass valve with Vaseline or grease before replacing the alloy cap should resolve the chemical reaction problem.

Asked on 2 February 2013 by AO, via email

Answered by Honest John
I have found that, contrary to the advise of aeronautical engineers, Copperease grease smeared between alloy wheels and iron hubs prevents them from fusing together. I don't know about these things, but I guess the introduction of a third metal affects the anodic reaction.
Similar questions
Having just paid £400 to have corrosion on the alloy wheels of a six-year-old car rectified, what do you recommend, firstly, to clean alloy wheels and secondly what to use to protect them from corrosion?
My Kia Rio failed an MoT on a faulty airbag device. This had to be replaced and recalibrated at a cost of £500. My seven-year warranty ran out in March although I have only done 7500 miles, not the 10000...
Can you recommend a non-corrosive alloy wheel cleaner which will remove marks, due to brake dust?
 

Ask Honest John

Value my car

Save £75 on Warranty using code HJ75

with MotorEasy

Get a warranty quote

Save 10% on GAP Insurance

Use HJ10 to save on an ALA policy

See offer