6J10-4-93-3 Testing.pdf

CHAPTER 7

TESTING

7.1 GENERAL.

This chapter provides procedures for testing the main gear fuel pump after assembly. Three different procedures for testing and fault isolation are contained here: fault isolation will determine the extent of repairs required, if any; break-in procedures will allow a technician to run the repaired pump to seat new or repaired components after assembly; and, re-certification test procedures will verify that the pump is ready to be returned to service. Refer to Figure 7-1 for test require-ments.

a. Refer to Paragraph 3.6 and perform preliminary in-spection prior to accomplishment of fault isolation.

Preliminary inspection procedures will determine the likelihood that running the pump during fault isolation will cause additional damage to the pump and/or pres-ent a safety hazard to the technician.

b. Refer to Paragraph 5.2 for definitions of inspection terms used in this chapter.

7.2 TROUBLESHOOTING.

This chapter will aid the technician in determining the depth of disassembly required to isolate and repair faults discov-ered during fault isolation.

NOTE

Prior to using Table 7-1, be sure that leakage and/or low flows and/or pressures are not the re-sult of damage to either the test fixture or the packings used during testing. Because of the unique design of the pump and its installation into the test fixture, leakage can be interpreted as a pump failure when in fact the failure may only indicate that a packing used during testing is bad or that the test fixture is damaged.

a. Refer to Table 7-1 to locate faults identified during testing and remedies for failures.

b. Refer to Figure 7-2 for a functional schematic of the fuel pump to assist in fault isolation.

7.3 TEST EQUIPMENT.

NOTE

• Either a manual test stand or automatic test stand PWA53110, described in TO 33D4-6- 716-1 (IPB TO 33D4-6-716-4), or automatic Advanced Fuel Accessory Test System 8230001-0503 (Reference TO 33D4-6-755-8-

15) shall be used for testing.

• If automatic test stand is used, executive soft-ware and UUT software shall be used. To be sure of the current version, check CPIN com-pendium 81-1-85 and most current TCTO to this publication.

a. Test Stand. The test stand used for fault isolation, break-in, and re-certification testing duplicates the drive and fuel control assembly interface for the pump.

The test stand provides a main drive shaft power source to drive the pump over a continuously variable speed range of 500 to 9000 rpm, a speed sensor, an oil mist system for lubrication of the pump main drive spline, a fuel boost pump to deliver fuel at 0 to 50 psig over a fuel flow range of from 800 to 118,000 phr, a heat exchanger to maintain fuel inlet temperature at a set point of 80°F within ±10°F for all operating condi-tions, a filter to remove all particles to at least a 25 micron absolute level, an inlet adapter, gear stage dis-charge adapter, augmentor boost discharge port, tem-perature taps, pressure taps, and rigid support during testing. A schematic diagram of the test stand is pro-vided in Figure 7-3.

b. Instrumentation. The nomenclature, designation, units, range, and accuracy of instrumentation for testing of the pump are listed in Table 7-2.

Table 7-1. Troubleshooting

Trouble Probable Cause Remedy External physical damage Mishandling. Repair per Chapter 6. Replace damage pins and inserts per Chapter 6.

Excessive seal leakage Packings worn or improperly seated. Replace packings.

Sealing faces of gears scored or rough. Replace gears.

TO 6J10-4-93-3

7-1

Table 7-1. Troubleshooting - Continued

Trouble Probable Cause Remedy Leakage at parting surface of hous-ings Packing worn or improperly installed. Replace packing.

Nicked or damaged packing grooves on volute housing.

Repair or replace worn components.

Low boost stage pressure rise Excessive boost stage clearances. Check boost clearances. Check for proper shim adjustment.

Volute housing damaged. Repair in accordance with Paragraph

5.5.10 or replace.

Impeller damaged. Inspect in accordance with Table 5-1 and repair or replace.

Low gear stage flow or pressure Gear stage gears or bearings exceed wear limits.

Check wear limits and replace worn parts.

Excessive wear in gear housing. Repair in accordance with paragraph

5.5.14 or replace.

Damaged packings on bearing. Replace packings.

Pressurized and/or fixed bearings not properly seated.

Install bearings in accordance with Para-graph 6.4.

Matched set gears not properly fitted. Replace or refit in accordance with Para-graph 5.5.13.

c. Test Fluid. The following test fluids may be used:

MIL-T-5624, Grade JP-4; MIL-C-7024D, Type II;

MIL-T-83133, JP-8; ASTM D1655, Jet A; or CAN/

CGSB-3.22-93 NATO F-40.

d. Test Conditions. The following test conditions must be maintained during testing of the fuel pump:

(1) Measure and record the specific gravity (refer-enced to water at 60°F) of the test fluid and the temperature of the test fluid at which the mea-surement was recorded.

(2) Maintain the test fluid temperature at the pump inlet at 80 ±10°F. Measure this temperature within 10 feet of pump inlet.

(3) Perform all tests and measurements at the pre-vailing ambient temperature, relative humidity, and barometric pressure at the test site.

(4) Unless otherwise noted, control pump discharge flow by means of a valve in the discharge line.

To prevent damage to pump, do not allow pump to exceed maximum and minimum allowable dis-charge pressures.

(5) Monitor the discharge pressure after starting the pump. The minimum and maximum allowable discharge pressures after starting are listed in Table 7-3.

Table 7-2. Pump Test Instrumentation

Designation Item Units Range Accuracy ±

- Date Days

- Time Hrs:Min 24:60 0.01

- Drive Speed rpm 0-9999 15 rpm

Q1 Gear Thru Flow phr 1600-24,700 1% lndication +30 phr

Q4 Aug. Thru Flow phr 800-118,000 1% Vindication +150 phr

P2 Pump Inlet Pressure psig 0-300 1 psig

7-2

Table 7-2. Pump Test Instrumentation - Continued

Designation Item Units Range Accuracy ± P3 Boost Discharge Pressure psig 0-300 1 psig P4 Gear Inlet Pressure psig 0-300 1 psig P5 Gear Discharge Pressure psig 0-2000 5 psig T2 Pump Inlet Temperature °F 0-500 2°F

Table 7-3. Allowable Discharge Pressure After Starting

Minimum Maximum Discharge Pressure (Psig) Pump Speed (Rpm) Discharge Pressure (Psig) Pump Speed (Rpm) 1

50 Below 1,000 650 Below 1,000 100 1,000-5,000 500 1,000-2,000 200 5,000-8,000 800 2,000-6,000

1200 6,000-7,000 1350 7,000-8,000 1

1 Maximum Allowable Discharge Pressure For Checking Relief Value And Other Special Test Is 1450 Psig.

7-3

Figure 7-1. Main Gear Fuel Pump Test Requirements

7-4

Figure 7-2. Schematic Flow Diagram of Main Gear Fuel Pump

7-5

7.4 TEST SETUP.

a. Refer to Paragraph 3.6 and verify completion of pre-liminary inspection.

b. Set up the automatic test stand PWA53110. Tighten all connections securely.

c. Mount the pump to the test stand mounting flange us-ing six bolts and washers. Position pump with drive shaft horizontal and filter downward.

d. Attach the test stand inlet adapter to the pump inlet flange using six socket head cap screws and washers.

Figure 7-3. Test Stand Schematic Diagram

7-6

e. Install closure in unused pump inlet port.

f. Connect the test stand gear stage discharge adapter to the pump main discharge port.

g. Install closure in the pump main bypass port.

h. Connect the test stand augmentor boost discharge port to the pump augmentor inlet port.

i. Install closure in pump speed sensor drive output port.

j. Place graduate with leakage sensor under seal drain.

k. Verify that pressure tap P2 in test stand inlet adapter is connected to inlet pressure tap PFO.

l. Verify that pressure tap P3 on test stand augmentor boost discharge adapter is connected to augmentor in-let pressure tap PFI.

m. Install pressure tap P4 in gear stage inlet pressure tap PDF1 on pump.

n. Verify that pressure tap P5 on test stand gear stage discharge adapter is connected to discharge pressure tap PDF2.

7.5 PUMP PRIMING.

• The maximum allowable pump operating speed shall be limited to 9152 rpm.

• The pump must be primed before starting.

a. Bring the CRT screen on the automatic test stand to a standby screen.

b. Enter the main gear fuel pump part number and serial number.

c. If the pump is being primed in order to accomplish fault isolation testing (Paragraph 7.6), relief valve pres-sure testing (Paragraph 7.7.1), recertification testing (Paragraph 7.8), or any combination of these tests, proceed to Step d, below. If the pump is being primed in order to accomplish procedures contained in break-in (Paragraph 7.7), then accomplish the following steps prior to priming and starting the pump:

(1) If present, remove the installed relief valve as-sembly in accordance with Paragraph 3.8, Step c.

and the following exceptions:

• Only remove lockwire if required for re-moval of the fully assembled relief valve assembly.

• Only discard packings if the relief valve assembly being removed will not be rein-stalled in the pump assembly after break-in.

(2) Install a known good slave relief valve assembly that has a verified set point of 1285 to 1315 psid in accordance with Paragraph 6.4, Step l. Prior to installation, accomplish the following:

(a) Visually inspect installed packings, backup ring, threads, and all surfaces of the slave relief valve assembly for evidence of con-tamination or damage that would damage the pump assembly or prevent successful testing.

If the slave relief valve assembly is found to be free of contamination and damage, then the use of new packings and backup ring is not required.

(b) If the packings and backup ring on the slave relief valve assembly are found to be con-taminated or damaged, then remove them and install new packings and backup ring.

(c) If the slave relief valve assembly is found to be contaminated or damaged, select another slave relief valve assembly and inspect it in the same manner prior to installation.

(3) Torque the slave relief valve assembly to 135 to 165 inch-pounds.

d. Select automatic test or semiautomatic test. Select semiautomatic test only for a partial test. If automatic test mode is selected, go to Step f, below.

e. Prior to starting the pump, bleed entrapped air by loos-ening the plug or connection at the following loca-tions: (Refer to Figure 7-2 for pressure tap locations.)

(1) Loosen boost stage discharge at EEC supply port.

(2) Loosen wash flow filter pressure tap at WFFI.

(3) Loosen augmentor inlet pressure tap at PFI.

(4) Loosen servo return port at SRFI.

f. The logic of the automatic test stand will open the bleed valves for inlet, gear discharge, augmentor dis-charge, and gear inlet ports.

7-7

g. The logic of the automatic test stand will pressurize test fluid at 15 to 25 psig inlet pressure until air-free test fluid flows from each connection as observed on drip indicator.

7.6 FAULT ISOLATION.

NOTE

• Fault isolation test is ONLY for assisting in the repair of the pump to determine the extent of repairs required, if any.

• Recertification and relief valve test are the ONLY test that will disqualify of qualify/cer-tify the pump.

General fault isolation, when used in conjunction with Para-graph 3.5, failure data and pump history review; Paragraph

3.6, preliminary inspection; and Table 7-1, troubleshooting, will aid the technician in determining the extent of repairs required, if any.

a. Verify that fault isolation has not been precluded by procedures in either Paragraph 3.5 or Paragraph 3.6.

b. Perform setup procedures in accordance with Para-graph 7.4.

c. Be sure that graduate is clean and dry.

d. Prime pump in accordance with Paragraph 7.5.

e. Refer to Table 7-4 and run fault isolation as listed.

Record required data in space provided in Table 7-4.

f. Record volume of fluid contained in graduate.

Table 7-4. Fault Isolation Run

Speed

(RPM)

±201

Filter Gear Stage Augmentor

Torque In-Lbs

Pump Inlet

(PSIG)

Time (Min.)

±1/2

Boost Dis-charge

(PSIG)

Gear Inlet

(PSIG)

D/P

(PSIG)

±20

Thru Flow

(PHR)

Thru Flow

(PHR) ±1000

Boost Dis-charge

(PSIG)

3000 1 1 300 1 10,000 1 1 1 1 1 1 400 1 10,000 1 1 1 1 1 1 500 1 10,000 1 1 1 1 1 1 600 1 10,000 1 1 1 1

700 10,000 2

6000 1 1 300 1 25,000 1 1 1 1 1 1 400 1 25,000 1 1 1 1 1 1 500 1 25,000 1 1 1 1 1 1 600 1 25,000 1 1 1 1 1 1 700 1 25,000 1 1 1 2

800 25,000 2

8000 1 1 400 1 45,000 1 1 1 1 1 1 500 1 45,000 1 1 1 1 1 1 600 1 45,000 1 1 1 1 1 1 700 1 45,000 1 1 1 1 1 1 800 1 45,000 1 1 1 1 1 1 900 1 45,000 1 1 1 1 1 1 1000 1 45,000 1 1 1 2

1100 45,000 2

NOTE

At start of run, pump to be accelerated to 3000 rpm within 20 to 30 seconds with minimum back pressure on gear stage. Inlet pressure 20±5 psig. Inlet temperature 90°±25°F.

1 Not necessary to record data.

7-8

g. Calculate the average seal drain rate by dividing the total leakage volume in cubic centimeters by the elapsed time under test in minutes. The maximum per-missible seal drain leak rate is 0.6 cubic centimeter per minute. No other visually discernible external leakage from the pump is permitted.

Seal Leakage cc/min (0.6 max) Test Stand No. Temp S/N Joint Leak Between & Tester

Other Leakage Date Perm S/N Fuel (specify): Specific Gravity °F

h. Refer to Paragraph 7.8 and perform recertification test-ing to identify faults.

i. Refer to Table 7-1 to determine depth of disassembly required, if any.

Table 7-5. Break-In Run

Speed

(RPM)

±201

Filter Gear Stage Augmentor

Torque In-Lbs

Pump Inlet

(PSIG)

Time (Min.)

±1/2

Boost Discharge

(PSIG)

Gear Inlet

(PSIG)

D/P

(PSIG)

±20

Thru Flow

(PHR)

Thru Flow

(PHR) ±1000

Boost Discharge

(PSIG)

3000 200 10,000 3

1 1 300 1 10,000 1 1 1 1 5000 1 1 300 25,000 1

1 1 400 1 25,000 1 1 1 1 7000 300 45,000 1

1 1 400 1 45,000 1 1 1 1 8000 400 75,000 1

1000 200 1 0 5 1 1 300 1 0 1 1 1 5 1 1 400 1 0 1 1 1 5 1 1 500 1 0 1 1 1 5 1 1 600 1 0 1 1 1 5

3000 1 1 300 1 10,000 1 1 1 2 1 1 400 1 10,000 1 1 1 1 1 1 Δ500 1 10,000 1 1 1 1 1 1 Δ600 1 10,000 1 1 1 2

700 10,000 5

5000 1 1 300 1 25,000 1 1 1 1 1 1 400 1 25,000 1 1 1 1 1 1 500 1 25,000 1 1 1 1 1 1 600 1 25,000 1 1 1 1 1 1 Δ700 1 25,000 1 1 1 2

800 25,000 5

7000 1 1 300 1 45,000 1 1 1 1 1 1 400 1 45,000 1 1 1 1 1 1 500 1 45,000 1 1 1 1 1 1 600 1 45,000 1 1 1 1 1 1 700 1 45,000 1 1 1 1 1 1 800 1 45,000 1 1 1 2

7-9

Table 7-5. Break-In Run - Continued

Speed

(RPM)

±201

Filter Gear Stage Augmentor

Torque In-Lbs

Pump Inlet

(PSIG)

Time (Min.)

±1/2

Boost Discharge

(PSIG)

Gear Inlet

(PSIG)

D/P

(PSIG)

±20

Thru Flow

(PHR)

Thru Flow

(PHR) ±1000

Boost Discharge

(PSIG)

1 1 Δ900 1 45,000 1 1 1 2

1000 45,000 5

8000 1 1 400 1 75,000 1 1 1 1 1 1 500 1 75,000 1 1 1 1 1 1 600 1 75,000 1 1 1 1 1 1 700 1 75,000 1 1 1 1 1 1 800 1 75,000 1 1 1 1 1 1 900 1 75,000 1 1 1 2 1 1 1000 1 75,000 1 1 1 2

Δ1100 75,000 5 1 1 Δ1150 1 75,000 1 1 1 1/4 max 1 1 Δ1200 1 75,000 1 1 1 1/4 max 1 1 Δ1250 1 75,000 1 1 1 1/4 max 1 1 Δ1300 1 75,000 1 1 1 1/4 max

1350 75,000 1/4 max 947 345 0 2

NOTE

• At start of run, pump to be accelerated to 3000 rpm within 20 to 30 seconds with minimum back pressure on gear stage.

• Inlet pressure 30±5 psig. Inlet temperature 90°±25° F.

1 Not necessary to record data.

7.7 BREAK-IN.

NOTE

• The Break-In is ONLY to seat new or repaired component after assembly.

• Recertification and releif valve test are the ONLY test that will disqualify or qualify/cetify the pump.

The main gear fuel pump assembly shall be subjected to the following procedures when the pump is assembled after re-pair and prior to re-certification testing. Break-in will seat new or repaired components after assembly.

Seal Leakage cc/min (0.6 max) Test Stand No. Temp S/N Joint Leak Between & Tester

Other Leakage Date Perm S/N Fuel (specify): Specific Gravity °F

7-10

a. Perform setup procedures in accordance with Para-graph 7.4.

b. Be sure that graduate is clean and dry.

c. Prime pump in accordance with Paragraph 7.5.

d. Refer to Table 7-5 and accomplish break-in run as listed. Record required data in space provided in Table 7-5.

e. Record volume of fluid contained in graduate.

f. Calculate the average seal drain rate by dividing the total leakage volume in cubic centimeters by the elapsed time under test in minutes. The maximum per-missible seal drain leak rate is 0.6 cubic centimeter per minute. No other visually discernible external leakage from the pump is permitted.

g. Refer to Table 7-1 to determine depth of disassembly required, if any.

h. If no failure has been identified and pump has met all requirements of Table 7-5, remove installed slave re-lief valve assembly and install the relief valve assem-bly previously removed using assembly procedures provided in Paragraph 6.4. Continue testing in accor-dance with Figure 7-1.

7.7.1 Relief Valve Pressure Test. If the relief valve as-

sembly was removed or repaired, resetting and calibration must be performed.

a. The relief valve cracking point is checked as follows:

(1) Perform setup procedures in accordance with Paragraph 7.4.

(2) Prime pump in accordance with Paragraph 7.5.

(3) Set the inlet pressure to 15 to 25 psig.

(4) Within 20 to 30 seconds, the pump will acceler-ate from 0 rpm to 7745 ±30 rpm with the pump discharge valve wide open.

To prevent damage to pump, do not allow pump to exceed maximum and minimum allowable dis-charge pressures.

(5) Slowly close the discharge valve until the pres-sure relief valve cracks and begins to bypass flow, as indicated by a sudden increase in interstage pressure and a decrease in pump discharge flow.

Augmentor flow should be zero.

b. The relief valve actuation point should occur at a gear stage pressure rise between 1135 and 1165 psid, where the gear stage pressure rise is determined by subtract-ing the gear inlet pressure from the pump discharge pressure. If the valve actuation point is not within set point limits, the relief valve must be reset, as follows:

(1) Reduce the discharge pressure to 200 to 300 psig and run for a minimum of 3 minutes.

(2) Loosen the relief valve locknut.

(3) If the valve actuation is premature, tighten the valve adjusting screw (clockwise rotation). If the actuation is delayed, loosen the adjusting screw (counterclockwise rotation).

c. The relief valve is calibrated as follows:

(1) Tighten the locknut by applying a clockwise torque of 80 to 110 inch-pounds while holding the adjusting screw stationary.

(2) Recheck the relief valve cracking point at least twice to establish valve consistency and record the required data.

(3) Throttle the discharge valve to reduce the pump discharge flow and cause the pressure relief valve to bypass the majority of the gear stage flow internally.

Table 7-6. Relief Valve Pressure Test

Shaft Inlet Gear Inlet Gear Discharge Gear Stage Pressure Gear Discharge Test Speed Pressure Pressure Pressure Rise (PSID) Flow (PHR)

Condition (±30 RPM) (±5 PSIG) (PSIG) (Max 1450 PSIG) Required Actual Required Actual Cranking 7745 20 1135-1165 19700-20700 High By-pass 7745 20 1300 Max. 4500-5000

Test Stand No.

Date Temp S/N

7-11

Table 7-6. Relief Valve Pressure Test - Continued

Shaft Inlet Gear Inlet Gear Discharge Gear Stage Pressure Gear Discharge Test Speed Pressure Pressure Pressure Rise (PSID) Flow (PHR)

Condition (±30 RPM) (±5 PSIG) (PSIG) (Max 1450 PSIG) Required Actual Required Actual Tester Perm S/N Fuel

(Specify):

Specific

Gravity °F

Do not allow the pump discharge flow to fall be-low 4500 phr and do not maintain this high-by-pass condition for more than 15 seconds.

(4) With a pump inlet pressure of 20 ± 5 psig and a speed of 7745 + 30 rpm, close the discharge valve until the discharge flow is 4500 to 5000 phr and record the data in Table 7-6.

(5) The pressure relief valve cracking point shall be at a gear stage pressure rise of 1150 ± 15 psid and the gear stage pressure rise under the high-bypass condition shall not exceed 1300 psid. If the relief valve test results do not fall within these limits, replace the relief valve assembly.

7.8 RECERTIFICATION TEST.

Re-certification testing will calibrate the pump and verify that the pump has been successfully repaired and is ready to be returned to service. Re-certification testing will also be used during fault isolation testing to identify values that do not meet minimum requirements.

a. Perform setup procedure in accordance with Paragraph 7.4.

b. Be sure that graduate is clean and dry.

c. Prime pump in accordance with Paragraph 7.5.

d. Refer to Table 7-7 and run calibration as listed. Record required data in space provided in Table 7-7.

e. Record volume of fluid contained in graduate.

f. Calculate the average seal drain rate by dividing the total leakage volume in cubic centimeters by the elapsed time under test in minutes. The maximum per-missible seal drain leak rate if 0.6 cubic centimeters per minutes. No other visually discernible external leakage from the pump is permitted.

g. Review recorded data in Table 7-7 and identify values that do not meet minimum requirements.

h. Refer to Table 7-1 to determine depth of disassembly required, if any.

i. Remove the filter cover and inspect the filter housing, cover, and fuel filter element for cleanliness. No un-usual quantity or type of contaminate or wear particle is permitted.

j. If pump passes test, preserve in accordance with Para-graph 7.9 and return to service. If pump fails test, refer to Table 7-1 to determine depth of disassembly re-quired to repair failure, and repair.

7-12

Ta bl e 7-

7.

R ec er ti fic at io n an d C al ib ra ti on R un

Pu m p Sh af t

A ug m en to r

G ea r St ag e

G ea r G ea r

G ea r Pu m p

B oo st B oo st

E ng in e

Sp ee d To rq ue

T hr u T hr u

Fl ow

St ag e St ag e

Pr es su re

R is e In le t

D is ch ar ge St ag e

R is e R ef er en ce

(R

PM

(I n- L

b) Fl ow (P

H R

In le t

D is ch ar ge

PS

ID

(P

SI

G

(P

SI

G

(P

SI

D

(P H

R

M in

R eq d A ct ua l (P

SI

G

(P

SI

G

R eq d

A ct ua l

R eq d A ct ua l C ra nk in g

2, S.

L

Id le

2, ,0

-6

K C ru is e

2, ,4

-9

K C ru is e

2, ,0

-9

In te rm ed ia te

,0

,0

7-

M ax im um

,0

,0

M in

In le t Te m p.

°F

In le t Pr es su re ps ig

A ug m en to r flo w in cl ud es ph r se rv o re tu rn flo w

Se rv o flo w he at in pu t no t re qu ir ed

Se al

L ea k-ag e cc

/m in

(0 .6 m ax im um

O th er L ea k-ag e

(N on e Pe rm itt ed

7-13

7.9 FINAL INSPECTION AND PRESERVATION.

The following instructions are the last procedures to be per-formed after testing and prior to returning the fuel pump to service.

a. Fill the fuel pump with filtered preservative type hy-draulic fluid MIL-H-6083, then drain fluid from pump.

b. Check the torque on impeller nut (Figure 3-3, 58) us-ing impeller nut spanner tool 100-49604 and a torque wrench. Refer to Table 8-2 for torque values and torque if necessary.

c. Inspect shaft spline (Figure 8-1, 2) on main drive shaft (Figure 3-3, 3) for wear, obvious damage, or excessive looseness. Replace main drive shaft if loose or dam-aged.

d. Check all ports for obstructions and clear if necessary.

e. Install plastic closures (Figure 3-2, 5, 6, 7, 8, 9, 10, and 11) in accordance with Paragraph 6.5.

f. Lockwire lube flow filter assembly (Figure 3-3, 29), plugs (Figure 3-2, 3) in PFO and PF1 ports, and fuel filter cover (Figure 3-3, 8) in accordance with MS33540 as shown in Figure 7-4. Lockwire relief valve nut (Figure 3-3, 17) with lockwire and lockwire seal. Crimp the lockwire seal.

g. Inspect pump mounting studs (46) in accordance with Paragraph 5.3. Apply torque of 100 inch-pounds to tighten stud. If stud moves or tightens, replace stud in accordance with Paragraph 5.5.9.

h. Visually inspect sealing surfaces for damage. Repair in accordance with Paragraph 5.5.1.

i. Inspect the nameplate (Figure 3-2, 1) in accordance with Paragraph 5.3 and, if necessary, repair in accor-dance with Paragraph 5.5.4.

j. Seal the fuel pump in a polyethylene bag and store it in a cool, dry location.

Figure 7-4. Shipping Closures and Lockwire

7-14

CHAPTER 8

TABLE OF LIMITS

8.1 GENERAL.

This chapter contains a table of limits which provides clear-ances, wear limits, and other data required for overhaul and repair of the pump assembly. Note that the dimensions listed as minimums and maximums are for new parts and are set up as ideal limits. Parts may continue in service if their di-mensions do not exceed the applicable dimensions. Dimen-sional limits listed in Table 8-1 are illustrated in Figure 8-1.

Torque specifications are provided in Table 8-2. Spring in-spection data are given in Table 8-3.

Table 8-1. Table of Limits

Figure 8-1 Reference Number

Figure 3-3 Index No. Description 1 2

Minimum (Inches)

Maximum (Inches)

1 3 Shaft spline 1 (0.096 pin dia.) 1.2352 1.2373 1 3 Spline wear step 0.004 2 3 Shaft spline 1 (0.080 pin dia.) 0.6051 0.6069 2 3 Spline wear step 0.002 3 18, 23 Preset dimension 1.016 1.036 4 41 Pin wear step 0.050

-5-, -6- 45 Parallelism of surface -6- to surface -7- 0.002 -5-, -6- 45 Cable chafing depth 0.045

7 47 Bearing diameter 1.0238 8 58 Journal diameter 1.0190 9 58 Face surface 63 microinches 10 58 Journal surface 6 microinches 11 60 Parallelism of hub to surface 0.0002 12 60 Parallelism of face to surface 0.0005 13 60 Impeller face 8 microinches 14 62 Spline 1 (0.080 pin dia.) 0.9491 14 62 Spline wear step 0.004 15 62 Thrust face surface 6 microinches 16 65 Ring height 0.439 17 65 Bore diameter 3.742 18 65 Seal surface 15 microinches 19 65 Pin slot wear 0.10 20 67 Face surface 32 microinches 21 67 Rim surface 63 microinches 22 67 Thrust face surface 20 microinches 23 72 Pin wear step 0.020 24 81 and 82 Load zone dry film removal 0.5 square inch 25 81 and 82 Bearing bore 1.1777 1.1786 26 84 Gear spline 2 (0.072 pin dia.) 0.7313 0.7336 26 84 Spline wear step 0.003 27 84 Gear spline 2 (0.072 pin dia.) 0.3957 0.3984 27 84 Spline wear step 0.004 28 85 Gear spline 2 (0.072 pin dia.) 0.3957 0.3984 28 85 Spline wear step 0.004 29 84 and 85 Gear teeth 1 (0.320 pin dia.) 2.3714 2.3750

8-1

Table 8-1. Table of Limits - Continued

Figure 8-1 Reference Number

Figure 3-3 Index No. Description 1 2

Minimum (Inches)

Maximum (Inches)

30 84 and 85 Gear tips 80 microinches 31 84 and 85 Journal diameter 1.1751 1.1756 32 84 and 85 Journal surface 4 microinches 33 84 and 85 Sealing faces 4 microinches 34 89 Bearing diameter 1.1777 1.1786 35 89 Load zone dry film removal 0.5 square inch 36 93 Bearing diameter 1.1777 1.1786 37 93 Load zone dry film removal 0.5 square inch 38 100 Thrust face finish 32 microinches 39 101 Bore diameter 0.3753 40 101 Sleeve bearing thrust face finish 32 microinches 40 104 Chafing location 0.045 41 116 Spline 1 (0.060 pin dia.) 0.3559 0.3577 42 116 Gear teeth 1 (0.070 pin dia.) 1.2696 1.2758 43 116 Journal diameter 0.3730 44 116 Journal diameter 0.3730 45 117 Spline 1 (0.080 pin dia.) 0.6031 0.6069 46 118 Gear teeth 1 (0.070 pin dia.) 2.3696 2.3754 47 118 Gear faces 20 microinches 48 118 Journal diameter 0.6851

1 Over pins 2 Between pins

Table 8-2. Torque Specifications

Figure And Index No. Description1 Torque Limit (Inch-Pounds) Figure 3-2, 3 Plug 45 to 55 Figure 3-3, 2 Bolt 30 to 35 1

17 thru 23 Valve assembly, relief 135 to 165 27 Plug 35 to 45 29 Filter assembly, lube flow 110 to 130 33 Bolt 30 to 35 1

39 Screw 15 to 20 1

46 Stud 180 to 300 53 Bolt 70 to 80 1

58 Nut, impeller 400 to 425 68 Bolt 70 to 80 1

77 Bolt 70 to 80 1

98 Screw, shaft, stop 30 to 35 1

113 Bolt 30 to 35 1

117 Shaft, drive, speed sensor 160 to 180

1 Specified torque is force above that required to turn fastener onto threads of mating part.

8-2

Table 8-3. Spring Inspection Data

Function 1 Figure 3-3 Index

No. Part No.

Free Length (Inches) 1

Working Length (Inches) Load (Pounds)

Filter preload 12 217325 2.572 (1) 1.117 33.5-36.5

(2) 0.917 38.5-41.5

Relief valve 21 217326 3.114 (1) 2.885 48.3-63.7

(2) 2.485 146.3-161.7

Filter bypass 36 217324 1.966 (1) 1.090 24.3-26.3

(2) 0.980 27.5-29.5

Anti-drain valve 43 217145 4.125 (1) 1.413 19-21

(2) 0.920 22.5-24.5

Bearing pressure 92 and 96 215136 0.405 0.300 3.6-4.4

1 The valves given in this column are not requirements, but are given only for information. The purpose of these values is to give guidance for the approximate length of the springs.

8-3

Figure 8-1. Limits and Clearances (Sheet 1 of 7)

8-4

Figure 8-1. Limits and Clearances (Sheet 2)

8-5

Figure 8-1. Limits and Clearances (Sheet 3)

8-6

Figure 8-1. Limits and Clearances (Sheet 4)

8-7

Figure 8-1. Limits and Clearances (Sheet 5)

8-8

Figure 8-1. Limits and Clearances (Sheet 6)

8-9

Figure 8-1. Limits and Clearances (Sheet 7)

8-10

CHAPTER 9

DIFFERENCE DATA SHEETS

9.1 INTRODUCTION.

Overhaul and test procedures for models included in this chapter are the same as the procedures for Model 708000-2 Main Gear Fuel Pump Assembly except for the specific dif-ferences noted in the applicable Difference Data Sheet.

through Chapter 8 contain complete overhaul and test infor-mation for Model 708000-2.

9.2 INDEX OF DIFFERENCE DATA SHEETS.

Models covered by Difference Data Sheets are as follows:

Part No. Page

MODELS 708500-1 AND 708500-2 . . . . . . . . . . . . 9-3

MODELS 713700-1, 713700-2, and 713700-3 . . . . . 9-9

9-1/(9-2 blank)

DIFFERENCE DATA SHEET

MAIN GEAR FUEL PUMP INSTALLATION PART NO. MODELS 708500-1 AND 708500-2

THE INSTRUCTIONS CONTAINED IN PRECEDING CHAPTERS OF THIS TECHNICAL MANUAL ARE

APPLICABLE TO THIS MODEL EXCEPT FOR THE DIFFERENCES CITED IN THIS DIFFERENCE DATA

SHEET.

1 INTRODUCTION AND GENERAL INFORMATION.

Same as Model 708000-2 except this model does not have a matched set housing and cover. Instead, it uses a gear hous-ing assembly and no provision is made for driving a hydro-mechanical speed sensor. This eliminates the requirement for the speed sensor cover assembly and its attaching parts and packings along with speed sensor drive shaft and its associ-ated gears and bearings. See Figure 9-1. The preformed packing that Model 708000-2 uses in the thrust bearing car-rier assembly is replaced with a teflon seal assembly in Mod-els 708500-1 and 708500-2. The only difference between Model 708500-1 and 708500-2 is the part number of the packing (Figure 3-3, 26) installed on the relief valve housing (23). Functional description is the same but when referring to schematic flow diagram, Figure 1-3, disregard the illustra-tion of the speed sensor drive.

2 SPECIAL TOOLS AND TEST EQUIPMENT.

Same as Model 708000-2 except pump assembly fixture 100-49076, Figure 2-12, is replaced by pump assembly hold-ing fixture 100-49402 and bearing assembly fixture 100- 49401 is used during assembly of this pump assembly. See Figure 9-2.

3 DISASSEMBLY.

Same as Model 708000-2 except as follows:

a. In Paragraph 3.1, Step f, and Figure 3-1, disregard those blocks that address removal of the speed sensor cover assembly and also steps that apply to disassem-bly of gear housing assembly.

b. In Paragraph 3.1, Step g, it is not necessary to discard preformed packing Figure 3-3, 115) since it is not used.

c. Refer to Figure 3-2. Plug (3), packing (4), and plastic closure (7) are not required. Two plastic closures (11) are required instead of one.

d. In Figure 3-3, item numbers 99 through 118 do not apply to Model 708500-1, which has a gear housing assembly rather than a gear housing and cover assem-bly. See Figure 9-3.

e. In Paragraph 3.8, Step h, packing (Figure 3-3, 71) be-comes teflon seal assembly (71). It is removed in the same manner as the packing.

f. Paragraph 3.8., step (i) is not required.

9-3

4 CLEANING.

Same as Model 708000-2.

5 INSPECTION, REPAIR, AND REPLACEMENT.

Same as Model 708000-2, except as follows:

a. Component inspection procedures contained in Table 5-1 that pertain to matched set housing and cover Fig-ure 3-3, 105 thru 112) and speed sensor driven gear (116), speed sensor drive shaft (117), and speed sensor driver gear (118) do not apply. Inspect gear housing assembly as described in Table 9-1. Item numbers used in Table 9-1 refer to Figure 9-3.

b. Table 5-2 contained in Paragraph 5.5.3 shall, for pur-poses of Model 708500-1 repairs, be replaced by Table 9-2. In all other respects the procedures contained in Paragraph 5.5.3 apply to Model 708500-1.

c. c. Disregard procedures contained in Paragraph 5.5.13.

Refer to Figure 9-3, and repair the gear housing as-sembly as follows:

Figure 9-1. Main Gear Fuel Pump Assembly, Part Number 708501-1

Figure 9-2. Special Tools

TO 6J10-4-93-3

9-4

(1) Remove damaged inserts (Figure 9-3, 1, 2, 3, and

4) from the gear housing assembly and replace in accordance with Paragraph 5.5.3. See Table 9-2.

(2) Replace stop shaft screw (Figure 3-3, 98) as fol-lows:

(a) Using a 5/16-24 UNJF-3A left-hand thread bolt, verify condition of LH locking helical coil insert Figure 9-3, 4) in the gear housing assembly in accordance with Paragraph 5.3.

• Stop shaft screw has left-hand threads and tight-ens by turning counterclockwise.

• Take care not to scratch bottom or sides of gear bores in gear housing assembly.

(b) Thread in stop shaft screw (Figure 3-3, 98) and torque to 30 to 35 inch-pounds above the run-in torque.

NOTE

Torque values listed are for dry assembly only.

There shall be no lubricant applied to threads of stop shaft screw (98) or to threads of LH locking helical coil insert (Figure 9-3, 4). Threads may be cleaned in accordance with Paragraph 4.3 if con-tamination of threads is suspected.

(3) Touch up exposed surfaces of housing with chemical conversion coating.

6 ASSEMBLY.

Same as Model 708000-2, except as follows:

a. In all text, substitute the nomenclature gear housing assembly for the matched set gear housing and cover assembly. References to item numbers 99 through 118

Figure 9-3. Gear Housing Assembly, Part Number 217148-1, Exploded View

TO 6J10-4-93-3

9-5 of Figure 3-3 do not apply to Model 708500-1. See Figure 9-3 for the gear housing assembly used on Model 708500-1.

b. In Paragraph 6.4, Step a change the pump assembly fixture 100-49076 to pump assembly holding fixture 100-49402. See Figure 9-2.

NOTE

For LH locking helical coil insert (Figure 9-3, 2), use helical insertion tool 100-49126.

c. In Paragraph 6.4, Step f, install thrust bearing carrier assembly (Figure 3-3, 67) into gear housing assembly in the same manner except as follows:

(1) See Figure 9-3 and verify condition of inserts (1, 2, 3, and 4) in gear housing assembly.

(2) Lubricate teflon seal assembly with STP oil treat-ment and install as shown in Figure 9-4. Teflon seal assembly replaces preformed packing (Fig-ure 3-3, 71).

d. Paragraph 6.4, Step k does not apply to Model 708500-1.

e. Paragraph 6.5, Step b does not apply to Model 708500-1.

f. In Paragraph 6.5, Step d, no plastic closure (Figure 3-2, 7) is required and two plastic closures (11) are required.

Table 9-1. Component Inspection

Figure And Index No. Part Name Inspection Disposition

Figure 9-3 (1 thru 6)

Gear housing assembly Visually inspect for scoring, cracks, breaks, corrosion, dirt, distortion, de-formed or stripped threads, deformed or loose helical inserts, and obvious damage.

Clean (Paragraph 4.3) or replace if damaged.

Penetrant inspect gear housing per ASTM E1417, for cracks or linear indications.

Replace assembly if cracks are discovered.

Inspect for deformed or loose helical inserts.

Repair inserts (Paragraph 5.5.3).

Table 9-2. Helical Coil Inserts

Figure 9-3 Part Insert Minimum

Thread Torque (Inch-Pounds) Item Number Number Size Size (Inch) Min. Max.

1 MS21209F4-15 0.250-28UNF-3B 0.357 3.5 30

2 93059-21 0.3125-24UNJF-3A LH 0.375 6.5 60

3 MS21209F5-25 0.3125-24UNF-3B 0.760 6.5 60

4 MS21209F1-15 0.190-32UNF-3B 0.270 2.0 13

TO 6J10-4-93-3

9-6

7 TESTING.

Same as Model 708000-2, except as follows:

a. When referring to Figure 7-2, disregard the illustration of the speed sensor drive.

b. Paragraph 7.4, step (i) does not apply to Model 708500-1.

c. In Paragraph 7.9, Step e, plastic closure (7) is not re-quired and two plastic closures (11) are required.

8 TABLE OF LIMITS.

Same as Model 708000-2, except as follows:

a. Limits and clearances provided for Table 8-1 and Fig-ure 8-1 reference numbers 41 through 51 do not apply.

b. The torque provided for bolt (Figure 3-3, 113) in Table 8-2 does not apply.

Figure 9-4. Installation of Teflon Seal Assembly

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9-7/(9-8 blank)

MAIN GEAR FUEL PUMP INSTALLATION PART NO. MODELS 713700-1, 713700-2, and 713700-3

THE INSTRUCTIONS CONTAINED IN PRECEDING CHAPTERS OF THIS TECHNICAL MANUAL ARE

APPLICABLE TO THIS MODEL EXCEPT FOR THE DIFFERENCES CITED IN THIS DIFFERENCE DATA

SHEET.

1 INTRODUCTION AND GENERAL INFORMATION.

Same as Model 708000 except these models incorporate a shorter filter bowl assembly, filter element, and some related parts must change to accommodate this modification. The preformed packing that Model 708000 uses in the thrust bearing carrier assembly is replaced with a teflon seal as-sembly in Model 713700. The difference between pump part numbers within this model are limited to changes in part numbers for seals and packings.

1.1 Description. Functional description is the same.

2 SPECIAL TOOLS AND TEST EQUIPMENT.

Same as Model 708000-2.

3 DISASSEMBLY.

Same as Model 708000-2 except as follows:

a. When removing and disassembling fuel bowl assem-bly and related components refer to Figure 9-5 for proper relationship of components.

b. Disassembly steps remain essentially the same. Deci-mal suffixes on index numbers indicate differences in part numbers.

4 CLEANING.

Same as Model 708000-2.

5 INSPECTION, REPAIR, AND REPLACEMENT.

Same as Model 708000-2.

6 ASSEMBLY.

Same as Model 708000-2, except as follows:

a. In Paragraph 6.4, Step f, install thrust bearing carrier assembly (Figure 3-3, 67) into gear housing assembly in the same manner except as follows:

(1) Lubricate teflon seal assembly with STP oil treat-ment and install as shown in Figure 9-6. Teflon seal assembly replaces preformed packing (Fig-ure 3-3, 71).

(2) More content required

b. Paragraph 6.4, Step n, install the additional teflon seal assembly into gear housing assembly as shown in Fig-ure 9-6, as follows:

(1) Lubricate teflon seal assembly with STP oil treat-ment and install as shown in Figure 9-6. Teflon seal assembly is used in addition to reciprocating seal (Figure 3-3, 44).

(2) More content required

7 TESTING.

Same as Model 708000-2.

8 TABLE OF LIMITS.

Same as Model 708000-2.

9-9

Figure 9-5. Fuel Bowl Assembly and Related Components

9-10

Figure 9-6. Installation of Teflon Seal Assemblies

9-11/(9-12 blank)