Table 3-7 Calibration of LDS-465-2 (Code A Pump)

TM 9-2910-226-34

Table 3-7 Calibration of LDS-465-2 (Code A Pump)

NOTE

The time given for test flud at 800 F. Test

fluid temperature above 800 F. will tend to

reduce time, while test fluid temperatures

below 800 F, will tend to increase the time

for the pressure to drop to 250 psig.

Check for visible external leaks at connections, around

the hydraulic head, fuel control unit shaft and plunger

drive gear. If no visible external leakage is present, the

leakage is internal. Presence of fuel as the fuel control

unit indicates a worn fuel control unit shaft, or a

damaged control unit packing. Install a new control

unit packing (para 3-44) and repeat test. If leakage is

Figure 3-168. Aligning scribe mark on timing device hub

still present, install a new fuel control unit (para 3-44).

with timing pointer.

Fuel leakage in the area of the plunger drive gear, as

observed through the timing window opening, indicates

a damaged hydraulic head, lower ring packing or a

worn fuel plunger. Install a new hydraulic head lower

b. Slowly actuate the nozzle tester until a pressure

reading of 400 psig is attained.

ring packing (Para 3-28) and repeat test. If leakage is

still present, install a new hydraulic head assembly

NOTE

(para 3-40). An external leak at the bottom of the

Do not exceed 425 psig as damage to pre-

formed packings may result.

hydraulic head flange indicates a damaged hydraulic

head upper ring packing. Install a new aulic head upper

c. The pressure will drop slowly. When pressure

ring packing (para 3-28) and repeat test.

drops to 350 psig, time the rate of pressure drop to 250

d. Install timing device cover and timing window

psig, If the time of pressure drop from 350 to 250 psig is

cover or fuel shutoff housing.

less than 30 seconds, leakage is indicated.

Change 2

3-100