How To Bleed Brakes On Your Electric Bike - You Can Do It, It’s EASY 

Usually it's a button head bolt, whereas the bolts holding the caliper together you never want to touch, take a bigger allen key and are "cap head" bolts.

The cup he used compared to an open ended syringe with no plunger, is the same thing. The syringe at the lever with no plunger is basically just a cup. There's a syringe at the caliper end in both cases, they are both the same setup really.

If oil comes out, it's under pressure and no, that shouldn't suck air in anyway. If oil comes out when undoing the caliper bolt, you had pressure in the hose which means either: 1. You pulled the brake lever without quickly opening and closing the caliper bolt to make the pressure equal out. 2. You did not fully open apart the pistons. 3. Or both! Make sure your pistons are fully apart with a block that's from a kit of the same brand as your brakes, so you know for sure it's the perfect size. Having the pistons fully pushed apart lowers the pressure in the hose to the lowest it can be and in theory with pistons fully apart, it should be the same pressure outside the hose as it is in the hose, zero pressure, thus no air goes in but no oil comes out.

Looks like a keyboard stand actually now that I think about it.

Because aligning a caliper again is a PITFA.

It’s a keyboard stand.

@@engr_e omg what an awesome hack!!

The screw or the hole? If it's the hole then it needs a helicoil, but upside down because you don't want shards of metal getting in the reservoir, but if a screw already stripped there, then there probably is shards in the reservoir anyway. Fully bleed oil through and keep throwing away the old oil, until no more shards come through + do the helicoil.