I'm rebuilding my calipers (1985 Honda CB650SC) and usually install the pistons using brake fluid as lubricant. (Manual says DOT 3 or 4; I'm using 3 and am happy with it. Not interested in exploring the virtues of 4, 5.1 or 5) These pistons are very tight, and I've damaged a seal while pressing them in. I've read of using grease on the piston, a light, light, coating. But: what grease? Permetex makes something compatible with brake fluid. I tried it with an Amsoil all purpose grease I use for most everything: it dissolved into the fluid, turning the fluid pink. Not sure what it did to the fluid. I've drained everything. Got new seals. Ready to install, but don't want to damage any more seals. Grease recommendations? Other advice? Many thanks.