Hi all, I’m about to swap over my discs and pads on this car for the first time. It’s a job I’ve done multiple times on previous cars, but I took a quick look at YouTube just to reassure myself there won’t be any ’surprises’… on the video I watched, the guy applied copper grease to the joining surfaces between the hub and the new discs (to allow for easier removal next time round). I’m sure I’ve never done this before and, to my logic, introducing anything between the two surfaces could lead to an uneven alignment (albeit very minor). Usually I just ensure both surfaces are clean and free from rust/debris. What‘s your opinion of this? Should you apply copper grease (or similar) here, or just ensure a clean metal to metal contact?
Where to use copper grease
- Thread starter Rjw76
- Start date
-
- Tags
- brakes copper grease discs
I've used both methods cleaned with no lube and cleaned with a light smear of lube, neither will harm anything and the latter will make light work at your next disk replacement and less hammering to get it free from the hub.
You won't see any misalignment issues at all, just apply grease between contact surfaces as normal, I add some to bolts for wheels, between hub & discs & back of pads, never been an issue at all
Thanks. Interesting that you say you add to bolts as well. I used to do the same until reading an engineering article that explained that you should never grease torqued bolts as the torque is based on metal to metal contact/friction - according to the article, you can easily over torque bolts that are lubricated with grease. But like you say, if you’ve never had an issue I’m sure it’s not that critical!
30 years of this method without 1 issue, speaks volumes mate & my father before me, sometimes research, internet etc are clouded by real world usage.
I hear your pov.
That's why I use snapon techangles myself to counter any excess to the best of abilities, but you also have to factor in age, possibly micro-millimetre stretch, variety of factors, but let's be honest, it's a wheel bolt & although it's stipulated 120-130nm, they can handle a hell of allot more as can the hub threads & the grease is actually nominal in the grand scheme of things & imho inconsequential.
I recently had a car that has rusted on bolts, took a hell of allot of torque to get them undone way over 200 easily, they also had been overtightened vastly, tap & die'd the threads on hub & bolts, tested & added minimal grease, torqued to about 127, no way that's going to ever cause an issue due to grease imho.
We all have our methods, mine have worked & not caused me or others any harm, so I think it's safe to share that with others.
I think you'll be ok to add a slither.
I hear exactly what you're saying, I'd always used grease prior to working on the railway without a problem, but due to the nature of it being public transport and being labelled as safety critical work, everything had to be done by the book and signed off by the engineer who did the job. If ever there is an incident, any relevant work and documentation is scrutinised for mal practices which is very sobering.
Yeap very true, has to be by the book, hence why vag states renew lots of bolts although they're perfectly reusable, the steering wheel spline bolt is one example, use once but mines been on off many times & numerous years without so much as a hint of issue's, however it's only my life that's in question, most days anyway, not thousands as per the rail, so that's understandable.
To be fair, that's a really good point - I had the tyres changed on a different car a couple of years ago, not long after some welding had been done which necessitated removing the wheel. The poor guy at the tyre garage had a hell of a job to undo the wheel bolts because of how much the welder had overtightened them... he ended up having to use a metre long breaker bar with a bit of scaffolding pipe extension and 2 people literally jumping onto it before the bolts turned! But I'm still using those bolts/hubs and have removed and replaced the wheels numerous times since without issue.
I've always sparingly applied grease to the hub before fitting new discs, initially using copper grease, ie Copaslip which is in fact furnace bolt grease - which was one or the first use for copper greases.
Since I've become more aware of greases and some issues with using them in inappropriate places, I tended to abandon my copper grease, except maybe to use it up below new discs. I've changed to using aluminium grease on the top of discs, ie between them and the alloy wheels and ceramic grease on brake pads - and silicon grease on calliper guide pins.
I change wheels at 6 monthly intervals ie Summer<>Winter, and always clean the bolt threads and even the hub threads if they need it, using the correct size of tap and die, I've never ever lubricated wheel bolt threads.
Copper grease, before I decided to change away from it, had started to acquire a less than positive name in the general plant maintenance world, which sort of surprised me at the time.
Since I've become more aware of greases and some issues with using them in inappropriate places, I tended to abandon my copper grease, except maybe to use it up below new discs. I've changed to using aluminium grease on the top of discs, ie between them and the alloy wheels and ceramic grease on brake pads - and silicon grease on calliper guide pins.
I change wheels at 6 monthly intervals ie Summer<>Winter, and always clean the bolt threads and even the hub threads if they need it, using the correct size of tap and die, I've never ever lubricated wheel bolt threads.
Copper grease, before I decided to change away from it, had started to acquire a less than positive name in the general plant maintenance world, which sort of surprised me at the time.
