quote:
Originally posted by labman:
Haven't read many of my posts? I am forever harping on the importance of rebuilding wheel cylinders and calipers and slathering them good with Sil-Glyde. Older instructions say use brake fluid. In the past, I have seen some greases, perhaps the VW stuff too that were maybe cellulose based. The trouble with brake fluid and special brake greases is that they are hygroscopic. That is the last thing you want out between the cups and the boots. Even when new, the boots do not do a perfect job of sealing out moisture, salt, and grit. Expose hygroscopic material to the moisture and salt, and expensive parts your life depends on corrode. The older the boot gets, the poorer it seals. It may still look good, but be letting salt and moisture in. Even flushing the brakes doesn't help the outer parts of the cylinder.
Ordinary grease will swell and ruin the rubber parts.
Sil-Glyde and other silicone greases will neither attack any rubber, or absorb water. It is the best thing for anywhere rubber meets metal.