Rust colour coming from centre of drivers side wheel

[rjcatch]

Morning all, i'm hoping somebody can shed some light on why this is happening. I recently had my front and rear disks and pads replaced and not too long after having this done i have started seeing a rust like colour coming out from the centre of my drivers side alloy.

 

Any ideas on what could be causing this?

 

Thanks

Russ

[J.R.]

Rusted driveshaft retaining bolt, corrosion between alloy wheel and the steel locating spigot of the hub.

 

Most likely the former, they can rust impressively.

[J.R.]

It could also be that the mécano sprayed some copper anti-sieze compound on the bub spigot to protect it from the galvanic corrosion and now it is migrating outwards by centrifugal force.

 

On reflection that is the most likely cause.

[Ootohere]

Try the touch test.  Does it feel like grease? Snif test.  Not the taste test.  Rusty water type discharge or grease type.  Later most likely. 

[Ray Luxury-Yacht]

10 hours ago, J.R. said:

It could also be that the mécano sprayed some copper anti-sieze compound on the bub spigot to protect it from the galvanic corrosion and now it is migrating outwards by centrifugal force.

 

On reflection that is the most likely cause.

 

Yes, i'll second this. In which case, it shows a decent mechanic doing things properly too.

[ApertureS]

10 hours ago, J.R. said:

copper anti-sieze

galvanic corrosion

I know its me being pedantic but copper based anti seize is conductive and actually can cause corrosion between different materials. It was perfectly fine on old cars where everything was steel or iron and the voltage differential wasnt much.

Whereas on steel to alloy/aluminum there is a much larger voltage difference causing more corrosion.

 

Instead a isolating anti seize should be used such as a ceramic or ptfe paste based one as these handle high temperatures also for glow plugs and such. I recommend Febi 26712 as a tiny amount goes a very very long way.

 

See below for a chart showing what materials can cause more corrosion - the further from 0 the number (voltage), the more electrons flow and the more corrosion that occurs. 

 

 

 

 

Edited 10 May, 2023 by ApertureS

[ApertureS]

26 minutes ago, Ray Luxury-Yacht said:

 

Yes, i'll second this. In which case, it shows a decent mechanic doing things properly too.

Definitely wouldn't associate copper grease with a decent mechanic for modern cars - No manufacturer of parts or vehicles has recommended copper grease in the last 20 years so it has absolutely no place in a modern workshop in my opinion, not only invalidating any parts warranties but also just makes an absolute mess!

(I hate the stuff if you hadnt guessed ) 

[Ray Luxury-Yacht]

Just now, ApertureS said:

Definitely wouldn't associate copper grease with a decent mechanic for modern cars - No manufacturer of parts or vehicles has recommended copper grease in the last 20 years so it has absolutely no place in a modern workshop in my opinion, not only invalidating any parts warranties but also just makes an absolute mess!

(I hate the stuff if you hadnt guessed ) 

 

Haha fair enough! Well, it would be a boring world if we all thought the same. Having personally experienced many wheels galvanically rusted to the hub and a b*tch to remove, in my opinion a thin skim of copaslip on the mating face works wonders.

 

But as I said, each to their own!  

[J.R.]

I like the genuine stuff from a tin on old school rusty suspension nuts & bolts, whenever you watch an Autodoc video they spray the aerosol stuff on everything, I reckon its just to show that they have actually removed & refitted the fastener.

 

Anyway my resolve eventually broke and I bought some of the aerosol stuff, I dont think there is anything but a microscopic trace of copper in it so no worries about galvanic corrosion, its just coloured grease not that you can really call anything that comes out of an aerosol grease, white grease is just as useless.

 

I've used it on my wheelnuts on the Skodas and all the trailers etc for the last few years, if I remove the wheelnuts after 6 months they are as stiff and resistant as if I had put them back on dry and there is no trace of grease or lubricant on the threads.

 

I think the stuff is a chocolate teapot, a mechanic would be better spraying on marker paint, even silly string would be as good as the copper grease sprays.

 

I cant think of anywhere where they would be of benefit and do a better job that oil or grease applied in the traditional manner.

Edited 10 May, 2023 by J.R.