HOUSING AS 3E7771 - Caterpillar

Product Support Program For Relocating The Unfiltered Oil Pressure Sensor On Certain 3508, 3508B, 3512, 3512B, And 3516, 3516B Commercial Engines
SMCS - 1924 PS40070
No
U-345
A-269
AU-219
S-179
H-129
O-301
TM-7 This Program can be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS40070" as the Part number and "7755" as the Group Number. If adminstered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If adminstered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
Termination Date
November 30, 2001Problem
The 3500B monitoring system may detect an artificially high oil filter differential pressure on engines equipped with canister or duplex style oil filters. The filtered and unfiltered oil pressure sensors are in a location that reads approximately 10 to 14 psi of filter differential pressure when the filters are new. The monitoring system will activate a high oil filter differential pressure warning at 15 psi. This does not leave enough margin to accommodate normal oil filter fouling and results in false high filter restriction warnings.
This service letter provides a procedure to relocate the unfiltered oil pressure sensor. Relocating the sensor results in a lower measured oil filter differential pressure. This should eliminate false high filter restriction warnings.
Affected Product
Model & Identification Number
3508 (5XM1-30, 3PS1-189, 3TS1-416)
3508B (3DM1-164, 7SM1-253, 6PN1-544, 1TW1-250, 2HW1-126, 3DW1-152, 5PS1-249, 1FZ1-434)
3512 (3RS1-329, 3WS1-133, 6PM1-39)
3512B (1PW1-356, 2GW1-236, 3ZW1-147, 4AW1-328, 8EM1-321, 8RM1-398, 1GZ1-301)
3516 (7KM1-52, 3SS1-314, 3XS1-407)
3516B (1NW1-124, 2FW1-187, 3CW1-236, 4BW1-337, 4TN1-231, 7RN1-857, 8KN1-379, 9AN1-178, 1HZ1-205)
Parts Needed
No parts are needed for this program.
Action Required
See the attached Rework Procedure.
Service Claim Allowances
This is a 2- hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
Oil Pressure Sensor Relocation
This procedure should only be performed on engines with canister or duplex style oil filters. Spin-on type filters are not affected by false high filter restriction warnings.
1. Unplug the unfiltered oil pressure sensor from the harness.2. Relocate the unfiltered oil pressure sensor and fitting from the top of the filter housing casting to the front. Refer to Illustration 1. The plug in the new pressure sensor location will be used to plug the port left open at the former location after the sensor and fitting are removed. 3. Reconnect the existing unfiltered oil pressure sensor wiring harness to the sensor in the new location. The harness should be long enough if some harness ties are cut and the harness is relocated. 4. Run the engine after completing the repair. Check for oil leaks. 5. Use Cat ET to check the filtered and unfiltered oil pressure. When the engine is running, the unfiltered pressure should be higher than the filtered pressure if the repair was done correctly.
X - Former unfiltered oil pressure port (Top of casting, behind fuel filter canister).Y - New unfiltered oil pressure port.