Using the 1U7326 Governor Calibration Bench{1264, 0778} Caterpillar

Introduction

The 1U7326 Governor Calibration Bench and the procedure given in this instruction can be used for the test and adjustment of the governors that are used on the above engines. For the procedure needed to remove and/or install the governor, refer to the Disassembly and Assembly Section of the specific engine Service Manual.

Reference: Service Manual.

Tools Needed

Prepare Calibration Bench For Test Procedure

1. Make sure that switches (1) and (2) are in the OFF position. Electrical power to the calibration bench must be disconnected.

2. Remove cover (3). Check the oil level in the reservoir. Add clean SAE 10W engine oil to the reservoir if necessary, until the oil level indicator inside the reservoir indicates the oil level is correct. Install cover (3).

3. Remove plug (5) and check the oil level in the variable speed drive. If no oil comes out of the plug hole, remove plug (4) at the fill port. Add an oil, selected from the "Recommended Oil Chart" that follows, until the oil seeps from the plug (5) hole. When the correct oil level is obtained, install and tighten plugs (4) and (5).

NOTE: Do NOT use engine oil in the variable speed drive. A friction type oil is required. Refer to the "Recommended Oil Chart" that follows.

Installation of Governor on 1U7326 Governor Calibration Bench

1. Remove the storage cover and gasket that normally covers reservoir (1) at location (A).

2. To install a governor on the calibration bench, proceed as follows:

* Align the calibration bench drive coupling with the governor drive gear. Do this by rotating the governor until the two drive pins in drive coupling (X) engage with the governor drive gear.

* When the drive pins engage with the governor drive gear, rotate the governor far enough to put the governor housing mounting holes in alignment with the corresponding mounting holes in the calibration bench.

* To fasten the governor to the calibration bench, use the same bolts and washers that are used to fasten the governor to the engine. If the governor mounting bolts are not available, use three 6V5218 Bolts (M8 × 1.25 - 35 mm long) with three 9M1974 Washers.

3. Install fittings (2), (3) and (5).

4. Remove the complete fuel transfer pump assembly.

5. Connect fluid lines as follows ...

... Line (6) from reservoir to fitting (3) ...

... Line (7) from the filter base to fitting (5) at the lubrication oil inlet ...

... Line (8) to fitting (2).

Install the pressure gauge on the quick disconnect connection at location (C) on the lubrication oil filter.

6. If there is a shutoff solenoid (9) on the governor, be sure it is latched in the run position. To do this, loosen the solenoid end cap and use pliers to pull center rod (10) OUT.

If the governor is equipped with an energize-to-run solenoid (non-latching type), the solenoid must be removed.

7. Install oil collector cup (11). Remove bracket (12) from its storage location and install it as shown.

8. Install lever (13) on throttle lever (14). Put 1U9786 Calibration Pin (17) through the front hole of oil collector cup (11), then into link pin (18) of the governor output shaft.

Turn throttle lever (14) clockwise (CW) to move link pin (18) out from the governor housing. This will permit calibration pin (17) to be installed.

Slide the collar over the end of calibration pin (17) at location (D), until it contacts link pin (18).

9. Connect one end of spring (15) to the hole in lever (14). Connect the other end of spring (15) to the hole in tachometer base (16).

10. Connect the test bench to a 240 Volt, 50-60 Hz electrical outlet.

11. Turn the lubrication pump switch to the ON position to start the lubrication pump. Lubrication pressure should stabilize between 205-275 kPa (30-40 psi).

With oil pressure stabilized and the throttle lever held in the HIGH IDLE position by spring (15), calibration pin (17) should make contact with the governor housing.

NOTE: When checking a previously adjusted governor, if calibration pin (17) does NOT make contact with the governor housing, the checking procedure can NOT be performed. The governor must be completely re-adjusted using the procedure given in the topic entitled Adjusting Procedure.

When adjusting a new or rebuilt governor, if calibration pin (17) does not make contact with the governor housing, use the 1U6672 Adjustment Wrench to turn Load Stop Adjustment Screw (19) OUT, until calibration pin (17) does make contact with the governor housing.

12. Put a 1U8815 Contact Point on the stem of 6V6106 Dial Indicator (20). Install dial indicator (20) into bracket (12). Adjust the position of bracket (12) so the contact point on the dial indicator stem is positioned in the center of the output pin.

13. Adjust the position of dial indicator (20) within bracket (12) so the indicator registers 8.00 mm on the dial face. Tighten screw (21) to lock the indicator in position and hold this adjustment. Check this adjustment dimension again and adjust if necessary.

When the indicator stays at the 8.00 mm dimension, release spring (15), then remove calibration pin (17) and the collar.

NOTE: The 8.00 mm dimension is the reference point for all other adjustments that are to be made on the calibration bench, so this initial adjustment MUST be correct.

14. Turn the calibration bench drive motor switch and the lubrication pump switch to the OFF position.

15. If the governor has been previously adjusted and only needs to be checked, refer to the topic entitled Checking Procedure in this instruction.

If the governor is new, rebuilt, or requires a change of the specifications, refer to the topic entitled Adjusting Procedure in this instruction.

Checking Procedure - For Checking A Previously Adjusted Mechanical Governor

The procedure that follows is used to functionally "check" a governor without the removal of the cover plug or seal on the throttle stop. This "check" is intended as an aid to determine if a governor is functioning correctly.

For example; if an engine performance complaint occurs, and the governor is suspected as the cause, this "Checking Procedure" should be used rather than the "Adjusting Procedure". The "Adjusting Procedure" would be used if the governor did not pass the "Checking Procedure".

1. Install the governor on the calibration bench, refer to the topic entitled Installation of Governor on 1U7326 Governor Calibration Bench in this instruction.

2. Connect the test bench electrical cord to a 240 Volt, 50-60 Hz, electrical outlet. Turn tachometer (5) ON.

3. Turn the lubrication oil pump switch to the ON position. When lubrication oil pressure stabilizes between 205-275 kPa (30-40 psi) on the pressure gauge, turn the drive motor switch to the ON position to start the governor calibration bench motor.

4. Turn the speed control knob counterclockwise (CCW) to the slowest speed. Check all fluid connections for leakage. Make repairs as necessary.

NOTE: Do not turn the speed control knob unless the test bench is running, or damage to the variable speed drive may result. Except in the event of an emergency, the speed control knob should ALWAYS be returned to the slowest rpm setting before the calibration bench is shut off.

NOTE: To ensure consistent test readings for the entire test procedure, ALWAYS approach a specified rpm setting from a minimum of 100 rpm above the rpm setting required.

All specifications for the governor adjustment procedure are in form SEHS8918 entitled Governor Performance Data. For purposes of checking a previously adjusted governor, the tolerance (±) factor should be doubled, and will be referred to as an expanded tolerance.

As an example, if a tolerance in the specifications is listed as ± 0.05 mm, then the expanded tolerance for this checking procedure would be increased to ± 0.10 mm. This expanded tolerance will NOT be listed in the specifications, but will need to be calculated by the governor calibration bench operator.

5. Adjust calibration bench speed to the specified LOAD STOP rpm. SLOWLY move the throttle to the LOW IDLE position, then SLOWLY move it back to the THROTTLE STOP position. DO NOT move the throttle again during this checking procedure.

NOTE: If the governor is not equipped with a fuel ratio control proceed to Step 10. For those governors that do have a fuel ratio control, continue with Step 6.

6. If the governor is equipped with a fuel ratio control (1); connect a regulated air supply, a hand pump or a squeeze pump to the fuel ratio control. DO NOT apply air pressure to the fuel ratio control at this time.

7. Make sure all air pressure to the fuel ratio control is shut OFF. Any air pressure that may have inadvertently been applied to the fuel ratio control must be removed (disconnect the air supply hose if necessary, to bleed off any air that may be trapped in the line).

8. Adjust calibration bench speed to the specified FUEL RATIO CONTROL rpm and check the FUEL RATIO CONTROL output dimension.

9. Use the air supply to apply 105 kPa (15 psi) air pressure to the fuel ratio control. Bleed off all air pressure, then again check the FUEL RATIO CONTROL output dimension. It should be within the specified expanded tolerance dimension.

10. Adjust calibration bench speed to the specified FUNCTION 3 rpm. The output dimension should be within the expanded tolerance dimension.

11. Adjust calibration bench speed to the specified THROTTLE STOP rpm. Wait one minute (or longer if the output dimension is still changing). The output dimension should be within the expanded tolerance dimension.

* If the governor tests good according to the preceding tolerance checks, it is operating correctly and can be used again without the need for any adjustment.

* If the governor failed only the FUEL RATIO CONTROL dimension check, that dimension can be reset and the governor can still be used without any further adjustment.

If the governor failed either or both of the other dimension checks, proceed with Step 12.

12. During factory dynamometer load testing it is sometimes necessary to adjust the THROTTLE STOP SCREW to provide the correct engine FULL LOAD RPM, due to slight variations in other engine components.

Although the adjustment is correct for that particular engine, the governor may be slightly outside its THROTTLE STOP, expanded tolerance specification, when tested separately using this "Checking Procedure".

The output dimension checked in Step 11 is considered to be the correct dimension if the governor that was tested ...

... is to be installed on the original engine that it came from and ...

... if the governor has the original "factory seal" on the THROTTLE STOP and ...

... if the engine still has the same injectors with the same fuel setting dimension ...

... if the governor being tested meets all three of the above conditions the procedure that follows beginning with Step 13 may be used to check governor function.

In all other instances, the settings specified in form SEHS8918 entitled Governor Performance Data must be used. Other settings will have an unknown effect on engine performance.

13. Increase calibration bench speed until the output dimension goes to zero. Then decrease calibration bench speed until the output dimension is 1.00 mm less than the specified THROTTLE STOP output dimension.

Wait one minute, or until the output dimension is stable.

14. SLOWLY reduce calibration bench speed until the specified THROTTLE STOP output dimension is reached, and wait until the reading is a stable reading. The speed at which the specified THROTTLE STOP dimension is reached may be higher, or lower, than the specified rpm.

Record the speed where the specified THROTTLE STOP output dimension occured. This rpm should be within ± 100 rpm of the specified THROTTLE STOP rpm.

NOTE: If the speed recorded is within the ± 100 rpm, proceed to step 15, otherwise, the governor should be completely readjusted. Refer to the topic entitled

Adjusting Procedure in this instruction.

15. Remove the factory seal on the THROTTLE STOP adjustment screw and back this screw all the way OUT.

16. Adjust calibration bench speed to the specified LOAD STOP output rpm. The output dimension should be within the expanded tolerance.

If this dimension is correct and the governor meets the requirements established in Step 12, continue on to Step 17.

If the governor does not meet these requirements, the adjustment procedure should be completely redone. Refer to the procedure given in the topic entitled Adjusting Procedure as given in the instruction.

17. Adjust calibration bench speed to the speed recorded in Step 14 of this procedure. Adjust throttle stop adjustment screw (2) to obtain the specified THROTTLE STOP output dimension.

Tighten the locknut on the adjustment screw, then again check the output dimension.

18. Increase calibration bench speed by at least 100 rpm. Then reduce calibration bench speed back to the speed that was recorded in Step 14 of this procedure. Again check the THROTTLE STOP output dimension.

If the dimension is not within expanded tolerance, do Step 17 again.

19. Reduce the calibration bench speed to its lowest setting. Then turn both the calibration bench drive motor switch and the lubrication pump switch to the OFF position. The tachometer will turn off automatically after a short period of time.

20. Use lockwire to seal the adjustment setting of the throttle stop adjustment screw.

Adjusting Procedure - Adjusting A New or Rebuilt Mechanical Governor

The procedure that follows is used to adjust a governor after it has been reassembled. There are certain governor adjustments that must be made during governor assembly. Refer to the Disassembly and Assembly section of the Service Manual for necessary information.

1. Install the governor on the 1U7326 Governor Calibration Bench.

2. Remove the plug from access hole (B). To remove the plug, first remove fuel ratio control (4), if so equipped. Insert a punch through the hole where fuel ratio control was removed, then use a hammer to carefully tap the center of the plug until it is loose enough to remove.

Do not install install the fuel ratio control until told to do so later in the test procedure.

NOTE: If the governor is not equipped with a fuel ratio control, there will be an aluminum plug at the fuel ratio control mounting location on the side of the governor housing. To remove this plug, use a hammer and punch to pierce the plug center, then use a suitable bar to remove the plug from its bore.

3. Use a 1U6672 Wrench to loosen low idle adjustment screw (1). Loosen throttle stop adjustment screw (2) until the throttle comes in contact with the stop on the governor.

Connect spring (3) to hold the throttle against the stop.

4. Use the 1U6672 Wrench to loosen load stop adjustment screw (4).

5. Connect the calibration bench electrical cord to a 240 Volt, 50-60 Hz, electrical outlet. Turn tachometer (5) ON.

6. Turn the lubrication oil pump switch to the ON position. When lubrication oil pressure stabilizes between 205-275 kPa (30-40 psi) on pressure gauge (6), turn the drive motor switch to the ON position to start the governor calibration bench motor.

7. Turn speed control knob (7) counterclockwise (CCW) to the slowest speed. Check all fluid connections for leakage. Make repairs as necessary.

NOTE: Do not turn speed control knob (7) unless the test bench is running, or damage to the variable speed drive may result. Except in the event of an emergency, speed control knob (7) should ALWAYS be returned to the slowest rpm setting before the calibration bench is shutdown.

NOTE: To ensure consistent test readings during the entire test procedure, ALWAYS approach a specified rpm setting from a minimum of 100 rpm above the rpm setting required. All specifications for the governor adjustment are to be found in form SEHS8918, entitled Governor Performance Data. If no values are listed in the specifications for a particular functional test, proceed to the next step in the test.

If any of the adjustments or function checks can not be made during the governor setting procedure, stop the procedure and inspect the governor for possible problems.

8. Adjust calibration bench speed to the specified LOAD STOP rpm. Adjust load stop adjustment screw (8) to the specified output dimension.

Tighten the locknut for load stop adjustment screw (8) and again check the dimension.

9. Increase calibration bench speed by a minimum of 100 rpm. Then reduce the speed back to the original specified LOAD STOP rpm to again check the governor output dimension.

If the dimension is not within the specified RECHECK TOLERANCE, do Step 8 again.

10. Adjust calibration bench speed to the specified FUNCTION 1 OUTPUT rpm. The output dimension should be within specifications.

11. Adjust calibration bench speed to the specified THROTTLE STOP rpm. Adjust throttle stop adjustment screw (9) to obtain the specified THROTTLE STOP OUTPUT dimension. Tighten the locknut for throttle stop adjustment screw (9), then again check the adjustment dimension.

12. Increase calibration bench speed by a minimum of 100 rpm, then reduce the calibration bench speed back to the original specified THROTTLE STOP rpm and again check the THROTTLE STOP OUTPUT dimension.

If the dimension is not within specifications, do Step 11 again.

13. Adjust calibration bench speed to the specified FUNCTION 2 (High Idle) rpm. The output dimension should be within specifications.

14. Adjust calibration bench speed to the specified FUNCTION 3 rpm. The output dimension should be within specifications.

NOTE: If the governor IS NOT equipped with a fuel ratio control proceed to Step 18. If the governor IS equipped with a fuel ratio control, continue with Step 15.

15. If the governor is equipped with a fuel ratio control, install it at this time. Connect a regulated air supply, a hand pump or a squeeze pump to the fuel ratio control. DO NOT apply air pressure to the fuel ratio control at this time.

Adjust calibration bench speed to the specified FUEL RATIO CONTROL rpm. Adjust fuel ratio control adjustment screw (10) to obtain the specified output dimension, then tighten the locknut.

16. Use the air supply to apply 105 kPa (15 psi) air pressure to the fuel ratio control. Bleed off the air pressure and again check the FUEL RATIO CONTROL output dimension.

If the dimension is not within specifications, do the second part of Step 15 again.

17. Apply the 105 kPa (15 psi) air pressure to the fuel ratio control and keep it applied until Step 21 is completed.

18. Remove spring (3) that connects the throttle lever to the tachometer base. (This will permit the throttle lever to contact the governor housing in the LOW IDLE position.)

19. Adjust calibration bench speed to the specified LOW IDLE rpm. Adjust low idle adjustment screw (11) to obtain the specified LOW IDLE output dimension. Tighten the locknut, then again check the output dimension.

20. Increase calibration bench speed by a minimum of 100 rpm. Then reduce speed back to the original LOW IDLE rpm. Again check the LOW IDLE output dimension.

If the dimension is not within specifications, do Step 19 again.

21. If applicable, adjust calibration bench speed to the specified FUNCTION 4 rpm. Output must be within the specified tolerance.

22. Reduce the speed of the calibration bench to its lowest setting. Then turn both the calibration bench drive motor switch and the lubrication pump switch, to the OFF position.

23. Install the fuel transfer pump on the governor housing and connect inlet line (12). Remove pressure gauge (6) from the quick disconnect fitting located on the filter housing. Install the pressure gauge on the quick disconnect fitting located at the transfer pump outlet, location (E).

With these connections, it is possible to measure transfer pump pressure across an orifice built into the calibration bench.

24. Turn the lubrication oil pump switch to the ON position. When lubrication oil pressure stabilizes between 205-275 kPa (30-40 psi) turn the drive motor switch to the ON position to start the governor calibration bench motor.

25. Adjust calibration bench speed to 1500 rpm. Transfer pump pressure should be 105 ± 30 kPa (15 ± 4 psi).

26. Reduce the speed of the calibration bench to its lowest setting. Then turn both the calibration bench drive motor switch and the lubrication pump switch to the OFF position. The tachometer will turn OFF automatically after a short period of time.

27. After the test procedure is completed, a new 7C6204 Plug (aluminum) must be installed in access hole (B). If the governor is not equipped with a fuel ratio control, it will be necessary to install a new 7C6205 Plug (aluminum) in the hole where fuel ratio control (13) would normally be installed.

NOTE: In the procedure that follows, when applying sealant to a plug, make sure that no sealant enters the governor housing at any time.

28. To install either plug proceed as follows:

* Make sure the plug bore in the governor housing is clean and free of burrs.

* Apply 5P3413 Pipe Sealant all around the edge of the plug, then position the plug in the plug bore in the governor housing.

* Using a hammer and a punch with a blunt end, carefully tap the plug in the center to expand the plug so it is tight within its bore.

29. Use lockwire to seal the adjustment setting of the throttle stop adjustment screw.