TM 9-2910-226-34 manually work the valve in the bore. Valve must be free with no sticking or binding. If valve does not operate freely, replace the hydraulic head assembly. g. Install valve (C), delivery valve spring (B), and screw (A), and torque tighten valve screw to 40-45 foot-pounds. Loosen screw and retorque to 40-45 foot-pounds two more times. 3-54. Delivery Valve Test. a. Rotate the drive coupling in a counterclockwise direction until the slotted, red painted tooth is one-half tooth to the right of the mark on the pump housing. b. Slowly actuate the nozzle tester and note the reading on the nozzle tester gages as the delivery valve opens. This will be evidenced by a sudden drop in pressure. The delivery valve should open between 250 and 400 psig. NOTE Do not exceed 425 psig as damage to preformed packings may result. c. If the reading is not within specification, remove the delivery valve and inspect the spring, valve, and seat for foreign matter or damaged parts (fig. 3-166). If spring is defective, replace spring. If valve or seat is defective, replace the hydraulic head assembly. 3-55. Hydraulic Head Leak Test. a. Remove timing device cover, timing window cover or fuel shutoff housing. Rotate the drive coupling in a clockwise direction until the mark on the advance unit hub is alined with the pointer (port closing) (fig. 3-168). Table 3-4. Calibration of LDT-465-1C (Code E Pump) 3-98