2-Way Check Valve

Remove check valve. Connect a vacuum pump to port "A" of check valve. See Fig 1 . Air should flow with about 1.46 in. Hg applied. Connect vacuum pump to port "B" of check valve. Air should also flow with about 1.73 in. Hg applied. Replace valve as necessary.

Fig 1: Testing 2-Way Check Valve

Courtesy of KIA MOTORS AMERICA, INC.