Product Support Program For Replacing The Governor Actuator Bracket And Linkage On Certain M312 And M315 Wheel Excavators Caterpillar

Product Support Program For Replacing The Governor Actuator Bracket And Linkage On Certain M312 And M315 Wheel Excavators

Usage:

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Caterpillar: Confidential Yellow

NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4915" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

Termination Date

February 28, 2001

Problem

Wear at the pivot point of the governor actuator plate assembly can cause loss of engine power. The pivot point of the actuator group has been redesigned for increased resistance to wear.

Affected Product
Model & Identification Number

M312 (6TL68-634)

M315 (7ML65-1214)

Parts Needed

1 - 175-6207 Repair Kit - Linkage Gp - Governor

Action Required

See the attached Rework Procedure.

Service Claim Allowances

NOTE: This is a 3-hour job.

Parts Disposition

Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

Attach.

(1-Rework Procedure)

Rework Procedure

REMOVAL OF PREVIOUS ASSEMBLY (Reference Illustration 1)

1. Disconnect the linkage at the fuel injection pump lever.

2. Disconnect the electrical harness at the back of the pressure reducing valve (PRV) of the governor actuator cylinder.

3. Remove the cylinder from plate assembly (8).

4. Remove bracket (12) from the engine.

5. Keep the following items for reuse with the new components in linkage group:

a. rod (2) and lock nuts (16 & 20)

b. ball joints nuts (21)

c. stop screw (27) and lock nut (26)

d. lock nut (17) at cylinder end

e. cylinder fastening bolts (24)

f. bracket fastening bolts and washers (25, 28, 29 & 30)

INSTALLING THE NEW BRACKET (Reference Illustration 2)

1. Install old screw (27) and old nut (26) on bracket (12).

2. Check for free movement of the actuation cylinder mounting plate at the pivot point with engine mounting plate. Install the new pre assembled bracket (12) to the engine.

3. Reuse old lock nut (17) and install new U-joint (7) and rod end (11) as deep as possible into the governor cylinder end.

4. Rotate lever (6) clockwise as far as possible and assemble the other side of U-joint (7) to lever (6) with pin (19) and cotter pin (14).

5. Rotate lever (6) counterclockwise and fasten the governor cylinder to plate assembly (8) with bolts (24).

6. When the cylinder rod is fully extended, turn screw (27) till it comes in contact with lever (6). Then turn about of a turn more to ensure 1 mm pre compression of the spring within the cylinder.

7. With old nuts (16, 20 & 21) and new ball joints (3&4), reconnect old rod (2): on one side, to lever (6). DO NOT CONNECT THE OTHER END OF THE ROD TO THE GOVERNOR LEVER AT THIS TIME.

8. Assure all pivot points of the linkage move freely. Any binding within the linkage should be eliminated to assure proper operation of the control system.

NOTE: Use care in handling and routing of all electrical cables. The two cables from the actuator cylinder should be strapped securely to the governor housing. Include a wide loop in these cables between the cylinder and governor housing to accommodate movement of the cylinder. (Reference Illustration 2)

LOW AND HIGH IDLE SPEED ADJUSTMENT

1. Start the engine and check the engine speed by moving the injection pump lever by hand against low and high idle set screws at the injection pump. If required, adjust to the following specifications:

Low idle 750 to800 rpm

High idle 2450 to 2500 rpm

2. Stop the engine and connect rod (2) to the center hole of the injection pump lever.

3. Make sure that the connector at the back of the governor cylinder pressure reducing valve (PRV) is disconnected. Start the engine and adjust the length of rod (2) to obtain the high idle setting shown below :

M312 2150 to 2170 rpm

M315 2400 to 2420 rpm

NOTE: Make sure there is no contact between the injection pump lever and the high idle stop screw of the injection pump. The only effective stop screw is screw (27) at high idle.

4. Secure the rod with lock nuts (16 & 20) at the ball joints (3 & 4).

5. Stop the engine and reconnect the electrical connector the governor cylinder PRV.

CALIBRATION AND ADJUSTMENT USING PDT (Portable Diagnostic Tool)

1. Connect the PDT to the service connector on the left side of the seat and start the engine.

2. Select "F1" / 2 "CALIBRATION" / 1 "SPEED DIAL CAL".

3. When requested "MIN POSITION", turn the speed dial to MAXIMUM speed, then press "ENTER".

4. When requested "MAX POSITION", turn the speed dial to MINIMUM speed, then press "ENTER".

5. You automatically get back into the previous menu, now choose number 2 "SPEED CAL".

6. Enter the low idle setting which should be between 1020 and 1040 rpm. Press "ENTER" and the calibration will run automatically.

7. After message "CALIBRATION ENDED OK", press "ENTER" again.

NOTE: Refer to Service Manual SENR8931 if you have an error message.

NOTE: If attempts at calibration are interrupted by 'Feedback' warnings at either the Portable Tech Station or Portable Diagnostic Tool, check for failed feedback wires at the point where the wires enter the governor actuator. Reference TIB on this subject dated (approximately) 7/99 for more detail.

8. On the M315 only use the "F1" / 3 "Speed Limit" / 2 "Work Limit" menu to adjust the bit value, which sets the work limit to 2150 to 2170 rpm (i.e. the maximum allowable engine speed in mode 2).

9. Use "F1" to 4 "LOAD RPM SHIFT" menu and check the RPM Difference setting in all 3 modes :