What was found
DURING CRUISE, PNEU PRESS READ 30 PSI WITH BOTH XFEED LEVERS CLOSED. WHEN EITHER LT OR RT AIRFOIL SWITCH TURNED ON PSI DROPPED TO ZERO. WHEN EITHER LT OR RT AIRFOIL SWITCH TURNED OFF, PNEU PSI WOULD SLOWLY BUILD BACK UP TO 30 PSI WITH BOTH XFEED LEVERS CLOSED. PERFORMED ADJUSTMENT & TEST FOR PNEUMATIC XFEED VLV CONTROLS IAW AMM 36-10-03-2-0. IT IS PERMISSIBLE FOR PRESS TO BE INDICATED ON INDICATOR WITH XFEED VLVS CLOSED. WHEN LT OR RT AIR FOIL SWITCH ON PRESS INDICATED IS 22 PSI OR LESS IS ACCEPTABLE LEAKAGE FOR XFEED VLVS.