I was this morning working with my Sanglas brakes. The pistons are stuck and so the pad rubs into the disc.
No big deal, let's remove them, tear them apart and clean them. As I was not going to pump brake fluid I just used gloves. I use googles everytime I fill or bleed the brakes, or whenever I use any power tools such as Dremel, grinder, drill etc.
The pistons had a small lip for a rubber dust. That is a great point to use a flat screwdriver as a fulcrum and pull the piston out. I managed to slightly break a little the lip in one of the pistons, no big deal. When it was the time for the last piston, while I was pressing the screwdriver, a small piece of the lip broke free and, due to the force exerted by the screwdriver, hit me hard on the face -I was working on the floor- on the cheek bone, less than one inch from my right eye. It made me a wound, with very slight bleeding. I thanked my guardian angel; it was so hard that had hit me in the eye it would have surely penetrated in the eyeball.
I always pride myself of having common sense and use the tools with the mentioned common sense, so trying to foresee dangers while using tools. But I couldn's see this coming -no pun intended-, I would have never imagined it would break and become a projectile. Don't forget about it when you are in your shop.
