WD-40 is not a valid lubricant. Period.
Every SMART millwright in industry will aggressively ring your neck if they catch you with a can of WD-40
It's primarily used to displace water off of surfaces, and it also contains a good amount of mild solvent (naptha/turpentine/whatever), making it useful for cleaning. But it's by no means a permanent lubricant.
Case and point, we all used WD-40 to lube our bike chains when we were young. Ever notice how they got RUSTY over winter? Yeah they don't do that when you use the proper gear chain or wax lubricant.
And it does absolutely disintegrate rubber seals. Note there are many different kinds of rubber used for seals, some are more prone to breaking down than others, and most rubbers are synthetic these days.
The industry standard is to never use WD-40 ever on anything. Use solvents if you need a solvent, and use lubricant if you need a lubricant.
Would you rather have 15% lubricant and 85% something else on your seals, or 100% lubricant?
Last edited by ThunderCactus; April 6th, 2013 at 15:35..