CYLINDER HEAD GP 3805795 - Caterpillar

Ensure that the engine is stopped before any servicing or repair is performed.
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, "Cat Dealer Service Tool Catalog" or refer to Special Publication, PECJ0003, "Cat Shop Supplies and Tools Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
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Ensure that the DEF dosing cabinet has been shut off and purged.
Disconnect the DEF line at the dosing cabinet and drain the DEF line into a suitable container.
Disconnect air and DEF lines from the DEF nozzle.
Remove flange bolts (1) and gasket.
Remove the DEF nozzle from the lance.
Inspect and clean the nozzle by flushing the nozzle (2) with distilled water. Soaking the nozzle in distilled water may help loosen any deposits.
Inspect the lance for crystallized urea deposits. Flush with distilled water as needed.
Ensure that the nozzle tip is clean.
Dry the nozzle.
Replace the flange gasket with a new gasket.
Reassemble, being careful to protect the nozzle when inserting the lance into the CEM. Replace any insulation removed during disassembly.Before assembly, Lubricate the threads using Loctite heavy duty (Nickel Free) Anti-seize and tighten to 17.6 2 N.m (155.8 18 lb in).Note: Tighten injector (3) to a torque of 17.6 2 N m (156 18 lb in).Note: Ensure that sensors are not covered with insulation. The insulation would trap heat in the sensor body and cable. This heat may cause sensor failure.
Install the DEF injector with the nozzle in the correct position. The correct position is in the direction of exhaust flow. Ensure that the mark on the injector flange corresponds to the mark on the CEM flange. Tighten the flange bolts to the proper torque. For standard torques, see Specifications, SENR3130, "Torque Specifications".
Install the air and DEF lines.