2.14.5 Hydraulic Manifold Valve Replacement Continued.
ECV engine rpm should not be adjusted above 1,500 rpm to obtain 8,950 to 9,050 rpm at
NBC fan. If ECV engine adjustment above 1,500 rpm is required, other problems are
Verify that NBC fan (14) is rotating at 8,950 to 9,050 rpm. If required, notify direct support to
adjust EPG to obtain 8,950 to 9,050 rpm at NBC fan (14). Do not exceed ECV engine speed of
Set EPG switch on vehicle control box to OFF and shut off ECV.
Start ECV engine and set EPG switch on vehicle control box to ON.
Verify that NBC fan (14) rotates at 8,950 to 9,050 rpm.
Steps 9 and 10 are for adjusting speed controls in non-NBC mode.
Leave ESS MODE selector switch on VENT and set NBC FAN switch to OFF.
Rotating adjusting screw on valve FP2 counterclockwise decreases NBC centrifugal fan
speed and clockwise increases NBC fan speed.
(10) Loosen locknut (15) on valve FP2 and rotate adjusting screw (16) as required to obtain 6,000 to
6,100 rpm at NBC fan (14). Tighten locknut (15).
Steps 11 through 18 are for adjusting speed controls in non-NBC VENT mode.
(11) Leave ESS MODE selector switch on VENT and ensure NBC FAN switch is ON.
(12) Gain access to recirculation fan.
(13) Using strobe light, check that recirculation fan is rotating at 1,550 to 1,659 rpm.
Rotating adjusting screw on valve FP6 counterclockwise increases recirculation fan speed
and clockwise decreases recirculation fan speed.
(14) If adjustment is required, loosen locknut (17) on valve FP6 and rotate adjusting screw (18) to
obtain 1,550 to 1,659 rpm. Tighten locknut (17).
(15) From top of ECU, disconnect flexible hose (19) from rib fan (20). Connect dial indicatin
differential gage (air flow) to rib fan (20).
To prevent damage to rib fan due to overheating, do not block air flow for more than one
Fluctuation of gage indication should be expected.
(16) On rear control panel, set RIB FAN switch ON. Momentarily block off air flow through dial
indicatin differential gage (air flow) by rotating valve to closed position.
(17) Check gage indication for a reading of 4.2 psi.