Author Topic: Copperslip on brakes? (Read 2499 times)

Brockett · « **on:** January 09, 2019, 17:09:14 »

I've been watching youtube videos. It doesn't matter what bike it was but when changing the pads the chap applied copper grease to the back of the pads. "To make sure nothing seizes". What? I have never done this, but it seems to be an almost universal myth and everyone of my mates do it and or believe it to be essential.
If you put grease anywhere in the caliper there is a chance it will find it's way onto the pad's face and disc.
Also grease in the caliper with cause dust, grit etc to bind together and maybe build up to contaminate the pads.
Maybe something dreamt up by those who want to sell copper grease.

tallpaul · « **Reply #1 on:** January 09, 2019, 17:12:13 »

For gawd sake don't do it. Matt from the Workshop has written evidence from EBC that you shouldn't do it. Delboy did this and was ripped to bits. It wasn't pretty...

SimonW · « **Reply #2 on:** January 09, 2019, 18:12:24 »

I thought it was done purely to avoid brake squeak

UK_Vstrom650 · « **Reply #3 on:** January 09, 2019, 18:17:42 »

It is. If I ride in rain there's loads of brake squeal unless I put a small amount of copper slip on the back of the pads.

Personally I don't see how it will migrate onto the braking surface unless you aren't careful when you apply it & just slap it on there getting it all over your hands/discs etc.

But each to their own. It won't kill you but it's also not 'necessary'

SimonW · « **Reply #4 on:** January 09, 2019, 18:51:37 »

Yes, like you I thought it was just the merest of smidges (give or take a thou'), which has almost nil chance of migrating onto the friction surface.

tallpaul · « **Reply #5 on:** January 09, 2019, 18:54:51 »

A bit of light entertainment...!

wurzel · « **Reply #6 on:** January 09, 2019, 20:11:55 »

A very thin smear can help stop brake squeal, but if all is as it should be it is not needed.trouble is most do not maintain calipers and change fluids, in salty environments things go pear shaped.

UK_Vstrom650 · « **Reply #7 on:** January 09, 2019, 20:59:36 »

I change my brake fluid every two years without fail, and sometimes more often (rebuilt the calipers twice in 6 years replacing all the seals etc but for some reason never timing it with the fluid change

) I'm also a habitual cleaner of the pistons - did them at the weekend. But you're right Wurzel, I still find that riding in wet weather esp through winter in heavy city traffic gives me brake squeal, which copper slip prevents. It also stops slider pins sticking in calipers too, and I've read quite a few posts over the years of people having to drill calipers to remove their pins.

wurzel · « **Reply #8 on:** January 09, 2019, 21:23:44 »

It is good to grease the pins and threads, also any caliper sliders.

SimonW · « **Reply #9 on:** January 10, 2019, 00:46:07 »

Quote from: tallpaul on January 09, 2019, 18:54:51

A bit of light entertainment...!

The email from EBC in that video says 'If you smear grease on the reverse of the pad it can find its way through the backplate and into the friction material...'.

Copper grease passes through steel? Or have I got that wrong?

tallpaul · « **Reply #10 on:** January 10, 2019, 06:19:13 »

I didn't scribe the email, but my guess is that they think that rather than risk a person's interpretation of "a smear" of grease it is better to not put any on. It doesn't affect the braking efficiency one way or the other, other than some people's experience of squeal. I only posted my response based on Brockett's first post and knowing that he has watched videos posted by The Workshop previously, so knows how intense Matt can get on absolutely any subject. Hence, for entertainment purposes!

Brockett · « **Reply #11 on:** January 10, 2019, 09:28:02 »

Yes of course lubrication is essential on the sliding pin although that is outside the caliper and within a rubber bellows.
I am interested in the opinions of other and I would not argue with anyone else's experience'.

What puzzles me is this.
1. The noise may be due to, a yet to be defined, component vibrating.
What component?

2 Given the forces at work and the pressure applied to the back of the pads by the piston(s) and caliper, How can it be the pads that are vibrating?

3 If it is the pads that are vibrating how is it that a smear of grease on the back of the pads reduces it?

Rusty Nuts · « **Reply #12 on:** January 10, 2019, 10:00:30 »

Ever made a wine glass "sing" by rubbing a slightly damp digit round the rim? (ooer, mrs) Dip Your digit in vaseline and try again. No vibes, no noise. Similar principle, maybe?

Ianmc · « **Reply #13 on:** January 10, 2019, 10:01:05 »

Self explanatory really,the noise is generated between the end of the piston and the back of the pad,which is where the copaslip is applied. Some pads have anti-vibration shims to attempt to stop the noise,but I still use a tiny smear of the grease on both sides of the shim when fitting and have never had any contamination issues in 50 yrs.

Brockett · « **Reply #14 on:** January 10, 2019, 12:38:56 »

Yes. Very interesting. I wonder if it is wear related. My SV, bought in June has 2200 miles and brakes do not have grease on their pads and yet do not squeal. However, although it gets wet it has not yet experienced a salty road.

Rookie · « **Reply #15 on:** January 10, 2019, 13:38:20 »

What! Just rebuilt my front calipers and used coppergrease. Now have to a decision as to leave alone or strip and clean again. Best have a pint ???? of cider and mull it over,or maybe just mull the cider????

Mr Nick · « **Reply #16 on:** January 10, 2019, 18:00:30 »

Pad contamination aside, there's also the galvanic element to using copper on cast aluminium and iron components that can actually make removing your bolts etc harder down the line, especially when it's parts that are open to the elements such as calipers and encounter water, especially salty.
I use copper grease on stainless engine bolts as the potential is only 0.15V between 18% stainless and copper(copper:cast aluminium is 0.6V), and the bolt itself is enclosed in the case limiting the access to an electrolyte.
Moly grease is even worse as the Disulphide is even more inert and causes a greater potential. This is why brake grease has active metals such as Lithium as that with be the sacrificial anode in the circuit if it gets wet.

Ianmc · « **Reply #17 on:** January 10, 2019, 19:02:51 »

When I started work in 1961,we were Girling and Lockheed agents.We used a special white grease on brake moving parts,adjusters,ends of shoes etc,and when we rebuilt master and brake cylinders we used rubber grease.Can’t remember the correct name of the white grease but it was affectionately known as n***** grease.(I don’t want the PC police involved so didn’t type the full word) We hardly had any problems with seized adjusters etc.Mind you the cars used to get a major service every 6k miles,and a minor every 3k so probably were never left long enough to get seized.

Brockett · « **Reply #18 on:** January 10, 2019, 19:44:59 »

Yes and I don't remember what it was called either ( just white brake grease). I used it on motorcycle drum brakes for all pivot points and (I confess) a slight smear on the high spots of the back plate that the brake shoes rested against. It didn't seem to melt or to contaminate the shoe material but without it on a single leading shoe setup the trailing shoe would not be effective or if it went on it tended to stay on.

Mudster · « **Reply #19 on:** January 10, 2019, 19:50:34 »

I will admit to using copper grease in the past to stop squealing pads. I stopped using it and I now use a small amount of ceramic brake grease on pins, sliders, back of pads. It's specifically designed for high temperatures and I'm a bit surprised it rarely seems to get a mention as an alternative.

To be fair, I never had a problem using copper grease, other than over time it tends to go all thick and 'goopy' which seemed to hinder brake bits sliding over each other.