I seldom find the "never had an issue" line very convincing, because I never know what the criteria for detection of "an issue" are, and I usually dont know what timescale is being discussed.

I used to use Coppaslip in the UK. Never had a single issue that I could definitively put down to it, but then I drove bangers of unknown history and never managed to keep them very long.

I did quite often see rubber components on them that had turned to mush, (a multiple issue), and Coppaslip was sometimes present. I dunno if Coppaslip was the cause, but if it was I would be unlikely to be able to prove it.

I daresay though, that if I hadn't run a vehicle in Taiwan (where it is unobtainable in non-industrial quantities) I might have continued to use it without giving it much thought. Now I have, though, and I now know that.

(a) It isn't specifically necessary in any situation I'm aware of. It either isn't necessary at all, or there are better alternatives.

b) There are specific reasons NOT to use it in particular circumstances, as I mention above

The better alternatives are not necessarily newer or more specialised. I have some "red rubber grease" (bought in Japan) which is perhaps specialised but not newer.(I think its castor oil base), and some Bendix Ceramic Brake Grease (bought in Australia, you can't get anything in Taiwan), which is newer, more specialised, and also horribly expensive, but I've never got around to using either of them.

Silicone grease and PTFE work just fine on the caliper pins.

On the sliders nothing works fine and costs...er...nothing.

The PTFE tape on the pad ears might work a bit better and costs very little, and I have at least once scribbled on the sliders with a 2B pencil. Dunno what that cost. Think I found it on the ground.

Next time around I might try some dry silicone spray as well if its to hand when I do the job.

I've kept my present 35 year-old car longer than any other I've had (think its 8 years now), and on that sort of timescale long term material incompatabilities might become more of a problem, and one I can do without.

Edited by edlithgow on 13/12/2021 at 15:07

Had 2 Focus's for 10 years, is that long enough?

I dont know. I've never had a car that young. It may be that newer cars use more oil resistant rubber.

Fortunately I don't need to know, since I have no need to use Coppaslip on brakes. So I don't

Thanks for your comments on the Red Rubber stuff (I think usually made by Castrol in the UK, but mine is of Japanese origin).

Its the recommendation in the Dahatsu manual I have, (though I can't recall exactly where one is supposed to use it) but I share your reservations about its longevity so havn't.

Temporary use as a piston assembly lube might make sense since brake fluid is quite an aggressive solvent so might keep it liquid.

I might be testing that soon, since I suggested a Japanese colleage use my sunflower oil and aluminium anti-rust treatment on his ratty old bicycle, but unfortunately he flooded all the moving parts with "salad oil".

Sure enough, his bike is now stiffening up. Going to be quite hard to free it up short of disassembly, but brake fluid MIGHT work.