The Parking Brake Needs To Be Updated On Certain 994 Wheel Loaders Caterpillar

The Parking Brake Needs To Be Updated On Certain 994 Wheel Loaders

Usage:

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Caterpillar: Confidential Yellow

NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.

NOTE: This Program must be administered as soon as possible. When reporting the repair, use "PI3664" as the Part Number, "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description Code. Exception: If the repair is done after failure, use "PI3664" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.

Completion Date

May 31, 1994

Termination Date

November 30, 1994

Problem

The parking brake needs to be updated on certain 994 Wheel Loaders. This new parking brake does not need adjustment.

Affected Product
Model & Identification Number

994 9YF1-11, 13-18, 20-29, 31-51

Parts Needed

Dealers will need to order parts for this Program.

1 - 3B8485 Fitting

1 - 8C6416 Nipple Assembly

2 - 2G5459 Screw

2 - 3J7354 Seal O Ring

2 - 4J5477 Seal O Ring

2 - 3K0360 Seal

1 - 4K6804 Seal O Ring

1 - 4K8864 Clip

3 - 6K2430 Seal

1 - 4L9564 Seal O Ring

20 - 5P8247 Washer

4 - 9P0469 Rod

1 - 8R8513 Retainer

1 - 8R9312 Guard

19 - 7S3997 Spring

4 - 8T0281 Bolt

1 - 8T0360 Bolt

15 - 8T3282 Washer (Used to pull 1044753 Shaft)

2 - 8T4121 Washer

1 - 8T4137 Bolt

1 - 8T4182 Bolt

4 - 8T5002 Bolt

4 - 8T7013 Bolt

1 - 2V2072 Guard

1 - 6V0852 Cap

12 - 6V5839 Washer-Hard

12 - 6V5842 Bolt

12 - 6V8154 Bolt

3 - 6V8398 Seal O Ring

1 - 6V8554 Nut

1 - 6V8569 Bolt (Used to pull 1044753 Shaft)

1 - 6V8628 Elbow

1 - 6V8639 Connector

1 - 6V8782 Tee

1 - 6V9000 Elbow

1 - 6V9167 Bolt (Used to pull 1044753 Shaft)

1 - 8X7657 Hose Assembly

4 - 9X7458 Seal

2 - 398923 Ring-wear

1 - 1002712 Yoke

4 - 1002714 Disc-Friction

1 - 1002715 Plate-Pressure

2 - 1002718 Piston

1 - 1002719 Plate End

4 - 1002720 Pin-Reaction

1 - 1002721 Anchor-Brake

3 - 1004910 Plate

1 - 1044752 Retainer

1 - 1044753 Joint-G-Univ

2 - 1052036 Bearing

1 - 1052433 Cage-Bearing

1 - 1057134 Shim Pack

2 - 1061866 Cylinder

1 - 1067439 Spacer

1 - 1081174 Block

Action Required

See the attached procedure.

Owner Notification

U.S. and Canadian owners will receive the attached Owner Notification.

Service Claim Allowances

NOTE: This is a 16-hour job.

NOTE: U.S. and Canadian Dealers Only - Eligible dealers may enter a Type 2 SIMS Report.

Parts Disposition

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

NOTE: MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.

Attach.

(1-Owner Notification)

(2-Rework Procedure)

Copy Of Owner Notification For U.S. And Canadian Owners

Rework Procedure

METHOD 1 (assembled on the machine)

Remove Existing Parking Brake And Front Drive Shaft

1. Lower bucket to the ground.

2. Block all four (4) wheels.

3. Pump brake pedal until brake accumulators are completely discharged.

4. Disconnect front end of 8R8515 slip joint group and move it out of the way.

5. Disconnect and cap hydraulic hoses to parking brake actuators.

6. Remove parking brake adjusters and actuators. See the power train disassembly and assembly portion of the service manual.

7. Remove parking brake. See the power train disassembly and assembly portion of the service manual.

8. Remove 8R9316 drive shaft (parking brake to front differential).

9. Remove the blocks that supported parking brake from frame. Grind the areas smooth where blocks were removed.

NOTE: On new frames, Step 9 will not be necessary.

Installation of Front Drive Shaft, Support Bearing, Grease Line And Parking Brake.

11. Make sure that the inside area of the 1052433 Cage and the two 1052036 bearings are clean. Apply MPGL lubricant to bearings and install them in 1052433 Cage. The bearings should be installed with the word "thrust" positioned back to back on the inside diameter of bearing races.

12. Measure the thickness of 1044752 Retainer with an outside micrometer near the odd positioned hole. Install the retainer without any shims. Use four equally spaced 6V5842 Bolts. Tighten the bolts to a torque of 55±10 N·m (40±7 lb ft).

13. Using a depth micrometer, measure through the odd positioned hole in the retainer. Subtract the retainer thickness from this measurement. This is the required shim pack thickness.

14. Use the outside micrometer to measure the 1057134 Shim Pack. It must be within ± 0.025 mm (± .001") of the measured requirement.

15. Remove the four bolts and retainer. Install the retainer with the required shims and 4K6804 Seal. Install all twelve 6V5842 Bolts with 6V5839 Washers. Tighten the bolts evenly to a torque of 55 ± 10 N·m (40 ±7 lb ft).

16. Lubricate the 6K2430 Seal lightly with MPGL Grease. Install seal in the I.D. of the 1044752 Retainer. Clean I.D. of 1052433 Cage. Lubricate the two 6K2430 seals lightly with MPGL Grease. Install the seals in the I.D. of cage.

NOTE: See Illustration 1 for location and orientation of seals. (The open face of all three 6K2430 seals should be positioned toward front of machine.

17. Install 6V8628 Elbow and 3J7354 Seal in grease port at bottom of 1052433 Cage. Orient the elbow about 40° from the center line of machine. Position it so that it is toward the right rear of the machine. Connect the 8X7657 hose assembly to the elbow using a 4J5477 Seal

NOTE: When installing 1052433 Cage on the machine be careful not to damage 6V8628 Elbow.

18. Install 1052433 Cage (grease port should be positioned at the bottom) and 1067439 Spacer (position two closer holes at bottom) in front frame using twelve 5P8247 Washers and twelve 6V8154 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m (94 ± 15 lb ft) plus 120° ± 10°. See Illustration 1.

NOTE: Position 1052433 Cage so that upper side is parallel with plate above it.

19. Install 1081174 Block to boss in frame using a 8T4121 washer and 8T4182 Bolt. Install a 6V900 Elbow and 3J7354 Seal in the block. Install the 3B8485 Fitting in block. See Illustration 2.

20. Connect the end of 8X7657 Hose with 4J5477 Seal to block. Position and secure hose in place using a 4K8864 Clip. Attach clip to boss in frame using a 8T4121 Washer and 8T4137 Bolt.

21. Install 1002721 Parking Brake Anchor to 1052433 Bearing Cage using two 8T5002 Bolts 180° apart. Tighten bolts with fingers. One "half moon shaped" cut out should be at the bottom and toward the rear of the machine.

22. Clean and position 1002715 Plate with spring cavities facing up. Place nineteen 7S3997 Springs in the cavities. One cavity will have only one spring, position it at the top.

23. Position the 1002715 Plate and springs against 1052433 Cage Bearing (springs facing cage). Be careful not to drop any springs. The cavity with only one spring must be at the top. Use four 8T0281 Bolts to secure assembly in place, compressing springs.

NOTE: Place plate and spring horizontally against lower section of cage and anchor. Keeping plate against edge, bring it to vertical position. If this does not work, use masking tape to hold springs in place.

24. Clean both ends of 1044753 Joint Group. Install 2V2072 Guard on shaft. Install 1044753 Joint Group through bearings and seals in 1052433 Cage. There is a tight fit between bearings and shaft. To pull shaft through bearings: clean 1002712 Yoke. Install 8R9312 Guard on yoke. Install yoke over splines in shaft. Make sure that yoke is installed in phase with yoke at opposite end of shaft. (All yokes from transfer gear case to front and rear differential should be in phase, if not, correct it at this time). Use 8R8513 Retainer, 6V8569 Bolt (M20 x 200) five 8T3282 Washers, and 6V9167 Bolt (M20 x 140) as needed to pull the shaft. Once the shaft is in position, install a 4L9564 Seal and 8R8513 Retainer using 8T0360 Bolt. Tighten the bolt to a torque of 475 ± 50 N·m (351 ± 37 lb ft). Connect the front end of the shaft to the front differential. Use four 9X6480 Bolts. Tighten bolts to a torque of 250 ± 20 N·m (384 ± 15 lb ft).

25. Install four 1002720 Pins in the 1002721 Anchor. Alternately place four 1002714 Discs and three 1004910 plates over splines in yoke. Remove two 8T5002 bolts that were holding anchor temporarily.

26. Install the 1002719 Plate to the 1002721 Anchor using four 5P8247 Washers and four 8T5002 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m plus 180° ± 5° (93 ± 15 lb ft plus 180° ± 5°). The side with two threaded holes (for eye bolts) should be positioned on top. Install four 9P0469 Rods through the holes in the 1002719 Plate.

27. Lubricate the 0398923 Ring, two 9X7458 Seals, and two 1002718 Pistons. Install these parts inside each one of the two 1061866 Cylinders. The face of the piston with a hole should be facing and aligned with the hole in 1061866 Cylinder. Install the 2G5459 Screw to each cylinder. Install cylinders on the parking brake assembly (bleeding screw on top) using four 5P8247 Washers and four 8T7013 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m plus 180° ± 5° (93 ± 15 lb ft plus 180° ± 5°).

28. Remove four of the 8T0281 Bolts holding the 1002715 Plate and place them in the storage position on front face of 1052433 Cage-Bearing.

29. Grease bearings with lithium base grease. The lubrication interval for these bearings is every 500 hours.

Installation of Hydraulic Lines to New Parking Brake And Front End Of 8R8515 Joint Group

30. Connect 8X9144 Hose (left side) to left parking brake cylinder using one 3K0360 Seal, two 6V8398 Seals, a 6V8782 Tee, a 6V8554 Nut, and a 8C6416 Nipple Assembly. Cover the nipple with a 6V0852 Cap-Dust.

31. Connect the 8X9144 Hose (right side) to right parking brake cylinder using a 6V8398 Seal, 6V8639 Connector, and a 3K0360 Seal.

32. Make sure yokes on 8R8515 Slip Joint are in phase. Use four 9X6480 Bolts to connect yokes on front end of slip joint. Tighten the bolts to a torque of 520 ± 20 N·m (385 ± 15 lb ft).

33. Lubricate slip spline with MPGL grease with machine fully articulated.

34. Bleed the parking brake: Start engine when brake accumulators are fully charged, release parking brake, loosen 2G5459 Bleeding Screws. Let them leak until no air is visible in oil. Tighten bleeding screws.

METHOD 2 (assemble parking brake then install it as a unit on the 994)

Remove Existing Parking Brake And Front Drive Shaft

1. Articulate machine completely to either side.

2. Lower bucket to the ground.

3. Block all four wheels.

4. Pump the brake pedal until brake accumulators are completely discharged.

5. Disconnect front end of the 8R8515 Slip Joint Group and move it out of the way.

6. Disconnect and cap the hydraulic hoses to parking brake actuators.

7. Remove the parking brake adjusters and actuators. See the power train disassembly and assembly portion of the service manual.

8. Remove the parking brake. See the power train disassembly and assembly portion of the service manual.

9. Remove 8R9316 Drive Shaft (parking brake to front differential).

10. Remove the blocks that supported parking brake from frame. Grind the areas smooth where blocks were removed.

NOTE: On new frames, Step 10 will not be necessary.

Assemble Parking Brake and Install Grease Line

11. Make sure that inside area of the 1052433 Cage and the two 1052036 Bearings are clean. Apply MPGL lubricant to bearings and install them in the 1052433 Cage. Bearings should be installed with the word "thrust" positioned back to back on the inside diameter of bearing races.

12. Measure the thickness of 1044752 Retainer with an outside micrometer near the odd positioned hole. Install retainer without shims. Use four equally spaced 6V5842 bolts. Tighten the four bolts to a torque of 55 ± 10 N·m (40 ± 7 lb ft).

13. Using the depth micrometer, measure through the odd positioned hole in the retainer. Subtract the retainer thickness from this measurement. This is the required shim pack thickness.

14. Use the outside micrometer to measure the 1057134 Shim Pack. It must be within ± 0.025 mm (± .001") of the measured requirement.

15. Remove the four bolts and retainer. Install the retainer with the required shims and 4K6804 seal. Install all twelve 6V5842 Bolts with 6V5839 Washers. Tighten the bolts evenly to a torque of 55 ± 10 N·m (40 ± 7 lb ft).

16. Lubricate the 6K2430 Seal lightly with MPGL grease. Install the seal in the I.D. of the 1044752 Retainer. Clean the I.D. of the 1052433 Cage. Lubricate two 6K2430 Seals lightly with MPGL grease. Install the seals in the I.D. of the cage.

NOTE: See Illustration 1 for location and orientation of seals. (The open face of all three 6K2430 Seals should be positioned toward front of machine.

17. Position the 1002715 Plate on a bench with the spring cavities facing up. Place nineteen 7S3997 Springs in the cavities. One cavity will have only one spring. Position it at the top. Place two spacers about 3" thick between the 1002715 Plate and the bench (1001866 Cylinders could be used). Position the 1002721 Anchor over the plate and springs with the "half moon" cut out toward bench (bottom) and opposite the cavity with one spring.

18. Place the 1052433 Cage Bearing over the anchor and springs. The lubrication hole on cage bearing should be on the same side as the "half moon" cut out in anchor. Use four 8T0281 Bolts to hold cage to the spring plate and to compress the springs.

19. Turn the brake assembly over (open end of anchor facing up). Use two 8T5002 Bolts 180° apart to hold the anchor to the cage. Tighten the bolts with fingers. Place four 1002720 Pins in anchor (longer end with larger chamfer goes into hole in anchor).

20. Clean 1002712 Yoke. Install the 8R9312 Guard in yoke. Place yoke inside anchor and cage. Alternately place four 1002714 Discs and three 1004910 Plates over the splines in the yoke. Remove two 8T5002 Bolts that were holding anchor temporarily.

21. Install 1002719 Plate to 1002721 Anchor using four 5P8247 Washers and four 8T5002 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m plus 180° ± 5° (93 ± 15 lb ft plus 180° ± 5°). The side with two threaded holes (for eye bolts) should be positioned on top. Install four 9P0469 Rods through holes in the 1002719 Plate.

22. Lubricate the 0398923 Ring, two 9X7458 Seals, and two 1002718 Pistons. Install these parts inside each one of the two 1061866 Cylinders. Face of piston with hole should be facing and aligned with hole in 1061866 Cylinder. Install 1G5459 Screw to each cylinder. Install cylinders to parking brake assembly (bleeding screw on top) using four 5P8247 Washers and four 8T7013 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m plus 180° ± 5° (93 ± 15 lb ft plus 180° ± 5°).

23. Loosen four 8T0281 Bolts enough to hold 1002712 Yoke in place. Install 6V8628 Elbow and 3J7354 Seal in the grease port at bottom of the 1052433 Cage. Position the elbow about 40° from center line of machine. Position it so that it is toward the right rear of the machine. Connect the 8X7657 Hose Assembly to elbow. Use 4J5477 Seal.

NOTE: When installing parking brake to machine be careful not to damage 6V8628 Elbow.

24. Install two eye bolts on cage of parking brake assembly. Lift parking brake and install it in front frame of machine use a 1067439 Spacer (position two closer holes at bottom), twelve 5P8247 Washers, and twelve 6V8154 Bolts. Tighten the bolts to a torque of 125 ± 20 N·m (94 ± 15 lb ft) plus 120° ± 10°.

NOTE: Position brake assembly so that upper side is parallel with plate above it.

25. Install 1081174 Block to boss in frame using a 8T4121 Washer and 8T4182 Bolt. Install 6V9000 Elbow and 3J7354 Seal in block. Install a 3B8485 fitting in the block. See Illustration 2

26. Connect the end of 8X7657 Hose with 4J5477 Seal to block. Position and secure hose in place using a 4K8864 Clip. Install a clip to boss in frame using a 8T4121 Washer and 8T4137 Bolt.

27. Clean both ends of the 1044753 Joint Group. Install 2V2072 guard on shaft. Install 1044753 Joint Group through bearings and seals in 1052433 Cage. There is a tight fit between bearings and shaft. To pull shaft through bearings: Make sure that yoke is installed in phase with yoke at opposite end of shaft. (All yokes from transfer gear case to front and rear differential should be in phase, if not, correct it at this time). Use 8R8513 Retainer, 6V8569 Bolt (M20 x 200), five 8T3282 Washers, and 6V9167 Bolt (M20 x 140) as needed to pull shaft. Once shaft is in position, install 4L9564 Seal and 8R8513 Retainer using 8T0360 Bolt. Tighten bolt to a torque of 475 ± 50 N·m (351 ± 37 lb ft). Assemble front end of shaft to front differential. Use four 9X6480 Bolts. Tighten the bolts to a torque of 250 ± 20 N·m (384 ± 15 lb ft).

28. Remove four 8T0281 Bolts holding the 1002715 Plate and place them in the storage position on front face of the 1052433 Cage-Bearing.

29. Grease the bearings with lithium base grease. The lubrication interval for these bearings is every 500 hours.

Installation of Hydraulic Lines to New Parking Brake And Front End Of 8R8515 Joint Group

30. Connect the 8X9144 Hose (left side) to the left parking brake cylinder using one 3K0360 Seal, two 6V8398 Seals, one 6V8782 Tee, one 6V8554 Nut and one 8C6416 Nipple Assembly. Cover the nipple with a 6V0852 Cap-Dust.

31. Connect the 8X9144 Hose (right side) to the right parking brake cylinder using one 6V8398 Seal, one 6V8639 Connector and one 3K0360 Seal.

32. Make sure the yokes on the 8R8515 Slip Joint are in phase. Use four 9X6480 Bolts to connect the yokes on front end of the slip joint. Tighten the bolts to a torque of 520 ± 20 N·m (385 ± 15 lb ft).

33. Lubricate slip spline with MPGL grease with machine fully articulated.

34. Bleed parking brake: Start engine when brake accumulators are fully charged, release parking brake, loosen 2G5459 Bleeding Screws. Let them leak until no air is visible in oil. Tighten bleeding screws.

Illustration 1 - Drive Shaft Group