Bleed screw

Bleed screws are also found on some pump types fulfilling a similar purpose.

The screw itself, usually a hexagonal or square knob, is inside a small round protrusion.

In other designs, the bleed screw is placed in the uppermost hose which leads to the heater core, i.e. at the highest point of the cooling system.

When liquid begins to flow out, all air has been removed from the system and the bleed screw is closed.

As a dead end of the hydraulic system, the slave cylinder is equipped with a bleed screw.