Rusty Brake Disc Flange - possible cure

[MUFFIN]

My K1 has started showing the dreaded signs of the rusty brake disc flanges visible behind the wheel.
I let one of our experienced workshop technicians take a look, himself a LEON Mk2 owner!!
He reckons the two types of metal, the alloy wheel and the cast disc are reactiing causing the visible rust. He reckons the part of the alloy touching the disc flange isn't laquered hence the problem when the materials come together..

Solution, remove wheel and rub down the surface rust on the flange area of the disc, apply coating of grease to rear of alloys at point of contact and around flange area.

I did this 2 weeks ago, so far so good. Will keep you posted..

I suggested painting them and he laughed


Do any of you experts have any comments on the above theory?

 

[Jedimaster65]

That may be true, but surely the biggest factor is the lack of proper paint finish on the flange itself...look at a new Honda, - you will see they are painted with Hammerite-style paint and don't suffer like the VAG cars.

 

[alx_chung]

Why don't you do both??? Make the hubs look a bit nicer and not have the rust problem?
Alex

 

[MUFFIN]

Why don't you do both??? Make the hubs look a bit nicer and not have the rust problem?
Alex

It may come to that if Bob's theory is flawed

 

[alx_chung]

Why don't you do both??? Make the hubs look a bit nicer and not have the rust problem?
Alex

It may come to that if Bob's theory is flawed

Yea I am tempted to do both once the good weather comes around. Have a tin of silver hammerite somewhere.........
Alex

 

[chrisboyle999]

'bob' is talking about dissimilar metal corrosion or galvanic corrosion which does indeed occur when 2 different metals are in contact with each other and other conditions are present.

this is unfortunately due to crap quality metal being coated in a crappy finish.

 

[Jon TDI]

As a matter of course, I apply copper grease to the contact points on the hubs.
Helps prevent the alloys seizing onto hubs.

I can live with the rust on the outside!