[RichardJ]

>>Brake systems are not to be used with teflon tape! Tape is to be used on tapered pipe threads only!<<

You are not understanding the use of the Teflon tape. The tape is not used to seal the brake system.

The tape is used to prevent leaks around the threads during the bleeding process. ONLY.

If you use one of the aftermarket self-bleeders with the internal valve, they usually include a tread sealer pre-applied in lieu of a Teflon tape.

The tapered end of the bleeder does all the sealing. Fluid moves past the open taper into the side hole and out through the nipple. A hose from the nipple into a collection bottle will not stop air from entering through the threads when the valve is closed during manual bleeding.

When vacuum bleeding, you can sometimes pull more air past the threads than fluid being pulled past the partially open taper seat. I.E. air enters around the threads, goes into the side hole and out the nipple, into the bleeder suction hose. Always use a collection reservoir so that you are not pulling fluid directly into the hand vacuum pump.

If you are using a Phoenix REVERSE FLOW BLEEDER, you will push more new fluid out past the threads than fluid past the taper seat INTO the system.