Implement Coupler Load Check Valves On Certain Challenger 35, 45, And 55 Agricultural Tractors Caterpillar

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 can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS5315" as the Part Number and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

Termination Date

Problem

On certain Challenger 35, 45, and 55 Tractors the implement hydraulic coupler load check valve ball(implement circuit numbers 1 and 2 only) may be held off of the valve seat because the bore depth (in the coupler housing) for the load check piston is too shallow. The result may be continuous leakage and "implement drift" when the "extend" or "+" port is pressurized.

Affected Product
Model & Identification Number

35 (8DN614-635, 8DN638, 8DN850-852, 8DN854, 8DN858, 8DN859)

45 (1DR1373-1426, 1DR1428-1440, 1DR1445, 1DR1449, 1DR1453, 1DR1701-1726, 1DR1728 , 1DR1729, 1DR1731, 1DR1735, 1DR1739, 1DR1740)

55 (7DM606-737, 7DM850-898, 7DM902, 7DM903, 7DM905, 7DM906, 7DM909-913, 7DM915)

Parts Needed

2 or 4 - 2J0157 Seal-O-Ring

2 or 4 - 5L4758 Seal-O-Ring

0 or 4 - 1327031 Fitting-Hose

1 or 2 - 1375752 Coupler Group

Action Required

See the attached rework procedure.

Service Claim Allowances

NOTE: This is a 1-hour job.

Parts Disposition

U.S. And Canadian Dealers

Return failed coupler groups to:

All Other Dealers

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

Attach.

(1-Rework Procedure)

Rework Procedure

1. After implement drift (associated with implement circuit #1 and/or #2) is reported, verify that the load check is the source of the leak. Attach tensioning hose group part number 1U9058 to the "EXTEND" or "+" port of the suspect implement circuit and make certain that the needle valve is open to the in-line pressure gauge. Start the engine and hold the implement control valve lever in the "RAISE/EXTEND" detent for five seconds before returning the control valve lever to the "HOLD" position. The pressure gauge should read approximately 18950 kPa (2750 psi) and should continue to hold at that pressure. Pressure decay indicates a leak at the load check valve and the entire coupler group part number 1375752 should be replaced.

Follow Steps 2 through 8 for Coupler GPS Requiring Replacement.

2. Disconnect implement coupler drain lines and remove complete coupler group (with load check valve) part number 1375752 from implement valve #1 and/or #2 (bottom two implement circuits).

3.

NOTE: Step 3 applies only to the NACD Marketing Subsidiary. None of the other marketing subsidiaries will be required to return failed coupler groups.

Paint mounting surface of the coupler housing yellow to clearly identify the part as a "used" coupler group with leaky load check valve.Ship failed coupler groups to the following shipping address (freight prepaid and added to the claim):

4. If replacing the coupler group for implement valve #1, install (4) hose fittings, part number 1327031, in the drain ports.

5. Install (2) 5L4758 O-rings and (2) 2J0157 O-rings in the housing drain ports of each coupler group replaced.

6. Install new coupler group, part number 1375752, to implement valve #2 and/or valve #1 and tighten hex socket head mounting bolts to a torque of 27 N·m (20 ft lbs).

7. Reconnect the drain lines to drain ports in the bottom of the coupler group.

8. Attach tensioning hose group to "EXTEND" or "+" port. Start the engine and hold the implement control valve lever in the "RAISE/EXTEND" detent for five seconds before returning the control valve lever to the "HOLD" position. Confirm that the pressure gauge reads approximately 18950 kPa (2750 psi) and continues to hold at that pressure.