Does coppaslip cause pads to stick ?

[DIYspanner]

Been talking to the garage that does my MOTs and he doesn't use copaslip coz it goes hard and makes the pads stick.

I know Mintex have marketed their own product so will try next time I fit some pads.

 

[Burnerman]

No it doesn't.....its used on the back of the pads to stop brake squeal. It shouldn't be used on the sliders as there's a possibility that coppaslip may rot the rubber, and in which case red rubber grease is used there.
The better compound these days is a white ceramic grease by Granville....actually stays where its needed!
John

 

[Dave54]

Never seen it happen. It goes dry and turns into copper powder if/when the grease burns off, but I've never seen it actually make anything difficult to remove. We used to use it on threads etc. on furnaces, where if they hadn't had it put on, the threads would be totally seized. I've always used it on virtually everything that had to work in the wet or got hot.

I often wonder about the "rots the rubber" thing John. I'm not suggesting that anyone does this or that it's safe to do, but a mate of mine used to assemble slave cylinders with Copaslip at the outer end. he never had any trouble with rear cylinders once done. I'm more cautious, I've always used rubber grease for the same job.

 

[Burnerman]

I guess it depends on what rubber actually is.....if its the old traditional stuff then coppaslip, being mineral base, would rot it in time. Red rubber grease is vegetable in formula so it doesn't have any adverse effect. Modern 'rubber' is largely synthetic.
For me, where slave cylinders are concerned, its a good smear of brake fluid on the pressure seal and then rubber grease around the dust seal - not that I rebuild them anymore!
Anyway, this ceramic stuff was a recent find for me.....more expensive but it lasts much longer.
John

 

[Dave54]

As you say, I haven't rebuilt one for years. last time I heard you couldn't get the seal kits any longer. I used to "hone" the old cylinders out with a piece of emery cloth held in a split piece of round bar in the drill press, and then wash them out thoroughly!
I wonder when they went from using "real" rubber to synthetic. Thanks for the tip on the ceramic goo, I'll try some next time I do the brakes, but at the rate I'm using Copaslip I should be well past my century before I run out!

 

[Belle427]

I stopped using it on sliders for the reason above but still use sparingly on pad to caliper contact surfaces and never have an issue.
I do use it on most suspension bolts etc come re assembly time, its a pleasure to take things apart after someone has taken the time to coppaslip things.

 

[DIYspanner]

Interesting reading folks, many thanks.

Granville ceramic grease, as recommended above, looks good and compared to Mintex Cera compound, is far cheaper by quantity it seems.

http://www.ebay.co.uk/itm/GRANVILLE...175982?hash=item3cf0c05bae:g:VSEAAOSwxYxUuP7U

Is the Granville grease safe on the slider rubbers ?


By the way, as well as coating the pad backs with grease, I've always coated the upper and lower edges of the metal back that make contact with the fixed bracket.

 

[Dave54]

Interesting that the item linked to says about it being a replacement for copper products which shouldn't be used on abs systems. And then if you search a bit online there are threads with arguments for and against as always.
Might well get some of that the next time front brake pads are done. Although it looks as if plenty of people are still using Copaslip.
Whatever is used I'd say use a minimal amount, and I'd still keep it away from the rubbers.

 

[mfarrow]

I would have said the late eighties, when EPDM started being used for hoses etc.

I usually use silicon grease on sliders, it won't rot rubber and it's what I've got in the toolbox.

 

[Dave54]

Yes, I can remember rubber seals and things being more "rubbery" at one time and then being more "plasticky" later. Must have been around when you say.
Interesting site here about red rubber grease, with tips for rebuilding various brake bits etc.
http://www.redrubbergrease.com/

 

[DIYspanner]

Granville make the red grease as well as the ceramic grease so I may as well get a tub of both - should last a long time as I only have four cars to look after.

Usually get Mintex pad and disc sets of an ebay seller so good quality all round. Having said that a local motor factor recently told me Mintex are now considered a budget brand but that's another discussion all together.

 

[Avocet]

I've also seen silicone grease recommended.

 

[nickso]

I do use it on most suspension bolts etc come re assembly time, its a pleasure to take things apart after someone has taken the time to coppaslip things.

I do that as well but some sources will tell you it will affect your torque values. By how much I don't know and I suspect few of us will bother to torque many bolts anyway so possibly a moot point.

 

[Dave54]

There's lots of argument online for and against using it, on the grounds of it altering bolt torques. I read somewhere that these copper based greases are designed not to lubricate too much and so don't effect torque that much. How true that is I don't know. I suppose you could also make the argument that torque values are with new, clean components, so if you (re)use a bolt with a rusty thread that might give an undertightened bolt.
Some makers apparently recommend the use of copaslip on wheel bolts (which seems to be the biggest bone of contention), and some others have apparently recommended it in amendments to service sheets.
As with a lot of things like this it seems to me that either way is wrong!

 

[nickso]

I only know I have never had a problem. I even put a light smear between the wheel and hub to stop the dissimilar metals sticking together.

A pal gave me a wonder thread lube from offshore years ago and it was great but I have run out and never seen it for sale since.