Designed for use with Mityvac Hand Pump. Aids in eliminating rapped air from GM power steering system. When installed, the adapters form an airtight seal in the neck of a vehicle’s power steering pump.
Worked great for getting rid of air in my power steering pump & lines after I changed it and flushed the lines. Just to be clear it does not screw down on the power steering pump neck, you have to hold it there with downward pressure while you pump the vacuum in the system. A little uncomfortable on your hands but it does get rid of the air. It says to hold the vacuum for at least 3 min., I held it for five and all the noise was gone.