CONTROL GP-COMMUNICATION 4946472 - Caterpillar

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.
Personal injury or death can result from improperly checking for a leak.Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death.If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Ensure that all adjustments and repairs that are carried out to the fuel system are performed by authorized personnel that have the correct training.Before beginning ANY work on the fuel system, refer to Operation and Maintenance Manual, "General Hazard Information and High Pressure Fuel Lines" for safety information.Refer to Systems Operation, "Cleanliness of Fuel System Components" for detailed information on the standards of cleanliness that must be observed during ALL work on the fuel system.
In order to service the fuel system on C175 Engines, the fuel that is under high pressure must be released. Use the following procedure to release the high-pressure fuel from the fuel system.
Allow the pressure in the fuel system to purge for 15 minutes.
Use the Caterpillar Electronic Technician (ET) in order to check the pressure of the fuel rail.Continue to monitor the pressure of the fuel rail if the pressure reading is higher than 1 to 2 MPa (145 to 290 psi).If the pressure reading is decreasing after1 minute, wait until the pressure reading has stopped decreasing.
High-pressure lines may be opened, once the pressure reading has dropped below 1 MPa (145 psi).Use the procedure below to release the remaining pressure that is in the system. If the pressure in the fuel system is still above 1 MPa (145 psi), proceed to Step 4.
Allow the system to purge for 15 minutes.
Follow the procedure below if the pressure reading does not decrease to less than 2 MPa (290 psi).Pressure Release by Loosening a Quill Tube
Note: This procedure is only required for one quill tube.
Illustration 1 g01311969
Loosen bolts (3) and (4) .
Loosen and remove bolts (1) and (2) .
Remove bolts (3) and (4) .Do not remove the quill tube.
Obtain new bolts.
Install the new bolts in the order of the numbered sequence that is shown in Illustration 1.BoltsApply clean engine oil to the threads of the bolts. Torque ... 20 N m (15 lb ft)Tighten the bolts again in the order of the numbered sequence that is shown in Illustration 1.Torque ...