F-16FuelPump_TestInstruction.pdf.pdf

TO 6J3-5-4-3

(1) Use a discarded gear which has the teeth ground q. If pins (88) were removed from pad (86), press off, and slip both bearings of a set on gear shaft. new pins (88) into pad (86) so that they extend

0.125 inch from the surface that mates with hous-

(2) Hold flats firmly against a piece of 500-grit or ing (87).

finer emery cloth, and move bearings across emery cloth, checking frequently to prevent r. Install pad (86) on housing (87). Install screws excessive removal of metal. (85), and torque to 24 to 27 inch-pounds.

(3) When properly dressed, there will be between s. Slide seal (84), plate (83), packing (82), ring (81),

0.0002 to 0.0006 inch between flats when bear- spring (80), coupling (79), and driver (78) onto ings (96) and (95) are installed in housing (87). drive shaft (75). Secure in place with ring (77)

(Figure 6-2).

k. After lapping bearings (96) and (95), clean with isopropyl alcohol and dry with cheesecloth. Refer t. Install packing (76) into housing (87) and install to CLEANING (Chapter 4). drive shaft (75) into pad (86) and housing (87).

u. Install retainer (74) on pad (86) using screws (73).NOTE Torque screws (73) to 11 to 13 inch-pounds.

Ensure that gear widths are marked to within

6.3 TESTING OF PUMP.0.0002 inch prior to installation of either reus-able or new gear set. Gears must be replaced as

6.3.1 A separate fuel pump test, as outlined in this para-a set.

graph, may be performed when Troubleshooting (Table 8-4) reveals that a faulty pump has been discovered;l. Install gears (94) and (93) in housing (87). Align or when new bearings and/or gears have been installed. existing gears (94) and (93) by matching blue layout dye marking on the mating teeth, if new gears (94) and (93) are not installed.

NOTE

CAUTION

Ensure bearing widths are matched to within

0.0002 inch. Install bearings as a matched set. Fuel pump rotation is counterclockwise when view-ing drive shaft. Failure to observe may cause com-

m. Install bearings (92) and (91) in housing (87). ponent malfunction.

n. If bearings (92) and (91) fail to slide into housing (87), it may be necessary to dress bearing (92) and

6.3.2 Pump Test Setup. Test shall be performed under(91) flats to allow insertion. Dress bearings (92) the conditions outlined in Table 6-1.and (91) as follows:

a. Install adapter plate ST60419 and gasket on auxil-(1) Use a discarded gear which has the teeth ground iary drive shaft end of pump.off and slip both bearings of a set on gear shaft.

b. Mount pump on fuel accessories test stand using(2) Hold flats firmly against a piece of 500-grit or adapter shaft from JFS fuel control adapter kit.finer emery cloth, and move bearings across emery cloth, checking frequently to prevent

c. Connect for test as shown in Figure 6-3.excessive removal of metal.

NOTE(3) When properly dressed, there will be between

0.0002 and 0.0006 inch between flats when bearing (92) and (92) are installed in housing If pump malfunctions during testing, refer to (87). Table 6-4 for probable cause and remedy. Test shall be stopped, pump shall be disassembled,

o. After lapping bearings (92) and (91), clean with repaired, and assembled, and tests shall be isopropy alcohol and dry with cheesecloth. Refer to repeated.

CLEANING (Chapter 4).

p. Lubricate packings (90) and (89) with petrolatum.

Install packings (90) and (89).

6-2

Table 6-1. Conditions for Pump Test

Ambient air Room temperature

Pumping medium Calibration fluid, Type II

Test fluid operating temperature 70 (±10)°F

Pump rotation Counterclockwise when viewing drive shaft

Inlet pressure Maintain as specified in test procedures

Instrumentation accuracy ±2 percent

Figure 6-1. Auxiliary Drive Seal

6-3

Figure 6-2. Drive Shaft Seal

6.3.3 Pump Run-In. b. Ensure all flow requirements are within required limits.

a. Run in pump in accordance with the schedule in

c. Inlet pressure shall be 5 to 10 pounds per squareTable 6-2.

inch gage (psig) for all tests.

b. In the event of a sudden rise in input torque or

6.3.5 Dynamic Shaft Seal Leakage Test.radically fluctuating discharge pressure, reduce drive speed and discharge pressure, until condition

a. With pump operating at 4200 rpm and dischargestabilizes; maintain inlet pressure at 10 psig during pressure adjusted to 600 psig, increase inlet pres-run-in.

sure to 60 psig.

c. During run-in, increase pressure in increments after

b. The maximum allowable test fluid leakage pastpressure and flow conditions are stabilized at each drive shaft shall be 1.0 drop per minute, measuredpressure.

over a period not greater than 15 minutes.

d. Reduce pressure to lowest setting before each pres-

c. Record leakage or none.sure increment increase.

6.3.6 Static Shaft Seal Leakage Test. With pump note. After completion of run-in, remove pump from bench test setup. operating and system pressurized to 75 psig, the maximum allowable test fluid leakage past drive shaft seal shall be 1.0

f. Measure breakaway torque with torque wrench. drop per minute.

Torque shall not exceed 12 inch-pounds.

6.3.4 Pump Calibration.

a. With test stand set up as shown in Figure 6-3, operate pump as directed in Table 6-3.

6-4

Table 6-2. Pump Run-In Schedule

Speed (RMP) Pressure Increments (PSI) 500 (±20) 20-50-100-150-200 1500 (±20) 20-50-100-150-200-250 2500 (±20) 50-100-150-200-250-300-350 3500 (±20) 50-100-150-200-250-300-350-400-450 4200 (±20) 50-100-150-200-250-300-350-400-450-500-550-600-700

NOTE

At 4200 rpm, gradually surge 100 to 700 psi three times, holding momentarily each time at this level. Reduce pressure to zero before increasing speed.

Table 6-3. Pump Calibration Requirements

Discharge Rate (PPH) Time Speed Discharge Pressure

(Minutes) (RPM) Minimum Actual (PSIG) 2 500 56.5 100 2 3000 500 2 4200 374.4 600 2 4500 600

NOTE

During calibration, leakage must not exceed one drop per minute.

Table 6-4. Pump Troubleshooting

Trouble Probable Cause Remedy Insufficient flow rate or Gear or bearing set defective Replace gear or bearing as required.

outlet pressure below minimum requirement Bearings defective Replace defective bearings.

Filter clogged Clean or replace filter element.

Excessive pump vibration Gear teeth defective. Bearing bores Replace defective gear and bearing set.

or noisy operation out of round or excessively worn

Shaft seal parts not properly in- Disassemble and correct alignment of seal parts.

stalled

Seal leaks Lapped seal faces damaged. Pack- Lap or polish sealing surface contact areas as ings in seal assembly defective required in accordance with paragraph 5.3.10; or replace defective parts.

Pump leaks at split between Raised metal on housing face or Disassemble and remove raised metal.

housing and mounting pad pad face preventing proper seating of parts Defective packing Replace packing.

6-5

Figure 6-3. Pump Test Setup

Figure 6-4. Installation of Special Bearing on Drive Head Assembly

6-6

6J3-5-4-3-WA-1.pdf