Brakes & Copper Slip.

[earthman]

Just heard Edd China say that you should not use Copper Slip when fitting brake pads, does he mean only if the vehicle has these disks with an aluminum inner hub??

I've used a very light smear of Cooper Slip on many brake calipers over the years, never had a problem.

[bare]

Bit of an Infomercial there. But He's right NO "slip goop" Certainly not on the back of pads.
Either you've been sparing in copperslip usage, not everybody is, Or you were fortunate.
It serves Zero purpose and it's possible that it might migrate to friction surfaces.
IF concerned about possible pad vibrations/squealing There are Sillycone pad dampening/isolation goops even tapes, readily available
Eddies' just babbling about ali calipers and iron rotors tho.
Pistons are Always steel there is No actual dissimilar metals contact where it matters

[earthman]

Oct 7, 2017 18:03:31 GMT 1 bare said:

Bit of an Infomercial there. But He's right NO "slip goop" Certainly not on the back of pads.
Either you've been sparing in copperslip usage, not everybody is, Or you were fortunate.
It serves Zero purpose and it's possible that it might migrate to friction surfaces.
IF concerned about possible pad vibrations/squealing There are Sillycone pad dampening/isolation goops even tapes, readily available
Eddies' just babbling about ali calipers and iron rotors tho.
Pistons are Always steel there is No actual dissimilar metals contact where it matters

Surely it's to aid with free movement of the pads and prevent rust build up?

I normally focus on the edges of the pads and the corresponding area within the caliper rather than the back of the pads as such, again it's a minimal amount I use, always been aware of not getting any on the disk/pad surfaces. 

[stusco]

When I last bought pads for my car I asked for some copper slip got told not to use it they sold me a tube of high temp stuff looks like normal grease so no mess works a treat stopped my front pads on my gold spots rattling

[earthman]

Oct 7, 2017 19:15:52 GMT 1 stusco said:

When I last bought pads for my car I asked for some copper slip got told not to use it they sold me a tube of high temp stuff looks like normal grease so no mess works a treat stopped my front pads on my gold spots rattling

Any idea on why that tube of stuff is suitable and copper slip now isn't?
Over the years I've used it on dozens of vehicles, strange that it's gone out of favour now??

[Deleted]

Generally the copper slip is used very very sparingly on new discs and new pads bed in

there are products out there for the back of the pad to stop the pad chattering, id replace the locating shims as they are most likely worn

mostly any other product on the back of the pad is used to stop the caliper piston welding itself to the back of the pad in extreme braking situations

unless you are racing or doing a lot of consistent hard braking then on a bike it shouldn't be required

[JonW]

Ive also used coppaslip for years on brake pads, I was told it stops the pad from screeching when it rattles in the caliper as the brakes are applied (usually light pressure) and the pad 'wobbles' across the piston causing the noise. Also used it on pins and the steel edge of pads as well to help noise. Ive recently used a Wurth product that did the same thing but was said to be better with no ill effects so interested that the idea now is not to use it.

I had issues on my new car Brembos with the brand new AcDelco springs (they were cheap and designed for the calipers its said) failing after a week and a single swap of pads (I didnt like the DS2500s I was using and fitted OEM pads instead), getting the OEM rattle springs (Subaru call them 'cross springs'... we figured as the price makes you cross) fixed the issue, but the next stage was that silicone type of glue mentioned to lock the pads to the piston, which i didnt fancy, seems like a bodge akin to the gloop you put in holed tyres. youd have to remove and redo that every new set of pads :/ anyway, with most car brembos the pads move, usually when you reverse and then move forwards, but the springs should fix that. Anyway, somewhat unrelated, just my take on the gloop...

Anyway, while i love Edd I do agree here the dissimilar metals comment seems superfluous when none of those things are touching as such i mean if that were the case the stainless spring plates and alloy calipers would screw eachother, sure its possible some copper flecks wont help any, it seems less of a factor when you've road salt etc. I mea how much copper is flying around here anyway? and while I take his point that coppaslip dries out, the particles do still provide lubrication at that point. What I did find worrying was his use of a wire brush on the rubber dust seals on the caliper when cleaning up the piston faces, thats not going to do em any good.

[Deleted]

Which Wurth product was it Jon?

Is it the sachet or a spray can?

One of the spray cans, Anti Squeal, is like a spraysble silicone to be applied to the back of the pad to stop the pad chattering to give some damping effect, it does work to "stick" the pad to the end of the piston, it doesn't Glue it and it's easy to remove the pad when worn, I'd say there wouldn't be much left of it after that much time though

The other spray can, brake protection is a ceramic based lubricant and is for slides and the back of the pads, plus any other parts that require lubrication apart from the pistons , it's rated to 1400C to prevent the pads welding themselves together

The sachet is much the same but has a lower temp rating and is an aluminium oxide base

Definetly not saying not to put any thing on the back of the pads, however I still think new anti squeak shins are the first port of call

I think some confusion is using the copper slip on the discs, Wurth did do a spray for that to help discs and pads break in but no longer, it worked well but was not copper grease

I have heard of some apprentices putting too much copper grease on a disc and then running the car into a wall cause they couldn't stop

HTH

Howard

[JonW]

It was a sachet Howard, a grey paste, tho the exact name escaped me tho i could check the workshop I purloined it from if you need me to? I used it to stop some squeal and it was fine, back of pads etc only of course. I didnt realise Wurth did the silicone version as well, id have been more interested in that if id known, but really the springs were too weak and that was my issue (even tho they were basically new, they'd lost their temper on the first day), and I suspect the issue of many who need to use that kind of product.

I agree shims are the thing most people need, but many car pads now come with a layer of a silicone on them for that purpose. depends on the brand and pad of course. FWIW I actually dont run any shims in my car Brembos... they dont squeal or rattle, just clonk when going from reverse to forwards, and vice versa, like all car brembo 4 pots as the pads move with the disks. Ive run plenty of these calipers and not had an issue leaving them out, but not all calipers are like that and I leave em in on most setups. Sadly the Brembo shims are not available as a separate part or I might have used them, tho they'd not have fixed my issue as it was spring related and as I said, Ive never had an issue leaving them out.

I still dont know why anyone would think you should lubricate a friction surface, especially a disk brake! The proper bedding in of pads as per the manufacturers recommendations is what they need, not applying anything other than a brake cleaner and while he says these have the special coating Id still clean them, they were made in a factory, packed in a factory and who knows how they were stored... and as Howard knows, I have a favourite of those too... yeah Wurth again. I have seen people lube the hub surface where disks and drums rust weld themselves to the hub. Id not think thats a good idea with any lube being flung out with centrifugal force, potentially onto the friction surface.

I love the fact Edd checks the run out. Thats superb, but Ive never seen anyone, let alone a DIYer do that when replacing disks. I love the idea that you should do it and that it proves you got the disk platter flat on the hub and that its not a duff disk, but how many will really do this... I dont think Ive ever done it on any car or bike disk, I run them after fitting and 99.9999% of the time they are spot on. Ok, Edd is giving us good practice, but there is a lot more to brakes than hes saying here but he only had a short time to tell us of course. Modern brake are clever things with integral shims, wear limit warnings and even easy bed in coatings. disks also come in different materials but of course you pay your money and take yer choice and some cheap ones for older cars can be total crap and yet even the <10 quid disks Ive bought for old clunkers over the years have been fine without testing for run out. My mate has a brake lathe, weve been restoring disks with it and the mess you start with can be illuminating if not scary, but thats another story.

What is interesting is that back in the day coppaslip was sold as a barrier for dissimilar metals in shops like Halfords. It was only recently that a mate alerted me to the fact that copper can actually make things worse with stainless in alloy and there was a whole table of how metals react on a bunch of sites. This had me panic'd, even tho Id never had an issue with using coppslip. Live n learn tho, Ive semi retired my huge pot of coppaslip now, sad but true, and if we cant use it on brakes then what can i use it for? I could rub it on my skin and use it for a bizarre fake tan... or use it to piss people off by putting small dabs of it in public places and see how it spreads, a little goes a long way... or maybe I'll just use it on exhaust studs, I hope i get a lot of exhausts to put on.

[midlifecrisisrd]

F*ck it I've always used it

Little smear on the back and side of the pad and the pad pins. If nothing else makes them easier to clean next time round

I've also always used it on stainless into alloy without problems

I've seen what happens if you don't. The bolts don't seize. They come out no problem but unfortunately the take all the alloy thread with them

To be honest anyway I reckon my current tube of copper grease has very little copper in it. Think it's more like copper coloured grease

Steve

[Deleted]

The paste is called AL 1100 Brake Paste and yes you put it on the back of the pads

You can use the copper grease on wheel nuts too or on any other steel to steel fastener to stop them corroding and enabling them to be undone, the only time you don't use it is in a salty environment

There is a special lube for stainless in alloy they use in the marine industry, its name escapes me ATM

You could use the high temp brake spray as it is ceramic based and is inert, we call it by another name, HSP1400, its the same stuff

[headcoats]

Only used it on the pins that hold the pads in , on brakes anyway

[Deleted]

I just stripped the head out of one of those pins on a old caliper that had seem better days

I don't think LH drill bits are going to cut the mustard

Any ideas

I do have spares though, so not such a big worry, still I'd like to get the bugger apart to recon it

[bare]

I always lube bolts and slider pins especially.
these would be messed after the first winter without a good clean and re-grease.
Don't understand applying grease to pad backs though... Clever isn't an apt descriptor
There are Silicone pads and even goops to apply for that purpose, (although many moderne pads come prefitted)... these Work..Period.
Rattling pads (reverse Klunks) I found was due to either excess wear in the Caliper block slots or more Often, undersized /poorly mfg'd pads.
Disc runout check was interesting, in that it was video'd.
A screw stick held close to a rotating disk gives quick visuals of a messed install.
IF there IS runout.. then it's either a crudded hub mating face OR a damaged hub and gawd knows what else.. serious issues far beyond fitting new discs / pads.

[p4ddy]

Pad pins and bolts but never on a pad. The whole idea of putting any kind of grease anywhere near a brake pad sends shivers through me.