853729 1 Mercury HOUSING, Pump

Introduction
Table 1
Revision History
Revision Summary of Changes
09 "Caterpillar Channel 1 Videos" Section has been added.
08 Step 4d has been rephrased with suitable verbiage. The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Caterpillar Channel 1 Videos
Illustration 1 g06471531Reference: For more information, refer to supplemental video "3500 & C175 High Pressure Fuel Line Leaks on Engines Using the CR-C Fuel System" on Caterpillar Channel1.Note: Click or copy the following link into a web browser (a CWS login is required to access Caterpillar Channel1), or scan the following QR code using a QR enabled device.https://channel1.mediaspace.kaltura.com/media/1_nnrmcene
Illustration 2 g06482399Problem
The fuel system leaks through the outer wall due to incorrect tolerance within the accumulator.Solution
Caterpillar is aware of this problem, but a permanent repair has not been identified. As an interim solution follow the rework procedure given below.
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
Note: Removal of the accumulator plugs when system leak is present, will allow for external leaking from the plug hole. Take precaution to collect the leaking fuel and not allow fuel to come in contact with hot surfaces or personnel.
Illustration 3 g06465783
(1) Accumulator plug
Remove all the accumulator leak detection port plugs (1).
The leakage from a fuel system overpressure can be severe and cause engine damage if the accumulator plugs are not removed prior to performing the Fuel System Functional Test.
Remove the accumulator leak plugs before running a "Fuel System Functional Test" to prevent overpressure of the double wall lines and potential contingent damage.
Run a "Fuel System Functional Test".
If the test passes proceed to Step 3.
If the test fails, proceed to Step 4.Note: Do not over torque or loosen joints for the high-pressure lines.
Verify the torque on all high-pressure line fittings and end plugs using the specifications below.
Line fittings - 105 5 N m (77 4 lb ft)
End plugs - 60 3 N m (44 2 lb ft)
Set the torque wrench to approximate value that is listed above for the component. Check the torque of each fitting or plug.
Check that all the high-pressure line clamps and brackets are installed in all required locations and installed properly.
Reinstall the accumulator leak detection port plugs and torque to 10 2 N m (89 18 lb in).
Return the unit to service.
Troubleshoot the failure using Troubleshooting , M0069788 , C175 Tier 4 Final Engines for Off-Highway Trucks. Use the procedure for a leak at an accumulator line joint.
Loosen the fittings on both ends of the two accumulator lines with 1 full turn.
Loosen the two accumulator clamp nuts one half turn.
Loosen both accumulator line clamps and brackets, keep the hardware properly aligned and finger-tightened.Note: Paint may need to be removed to allow the accumulator nuts to be loosened.
Ensure that the accumulator stud does not turn or loosen.
Lightly snug the fittings on both ends of the two accumulator lines until the fittings are fully seated in the accumulator.
Evenly tighten both accumulator clamp nuts to 35 4 N m (26 3 lb ft).
Torque the fittings on both ends of the two accumulator lines to 38 N m (28 lb ft).
Torque the fittings on both ends of the two accumulator lines to 105 5 N m (77 4 lb ft).
Tighten the accumulator line clamps and brackets to standard torque.Note: Ensure that the clamps and brackets are not binding on the lines.
If the leak remains unresolved, replace the impacted hardware using Disassembly and Assembly , M0067480.
Proceed to Step 5.
After a leak is resolved, rerun the "Fuel System Functional Test" with the accumulator leak detection port plugs removed to verify that there are not any other leaks in the system.
Reinstall all the accumulator leak detection port plugs to 10 2 N m (89 18 lb in). Tighten the end plugs to 60 3 N m (44 2 lb ft). Return the unit to service.