Perkins 1104D, When you install a new top compression ring, make sure that the word “TOP” is facing the top of the piston. New top piston rings for naturally aspirated engines have a red identification mark which must be on the left of the ring end gap when the top piston ring is installed on an upright piston. New top piston rings for turbocharged engines have a yellow identification mark which must be on the left of the ring end gap when the top piston ring is installed on an upright piston.
Piston Cooling Jet Alignment
Use the following procedure in order to check the alignment of the piston cooling jet:
- Insert rod (3) into the end of the piston cooling jet (2). Rod (3) has a diameter of 1.70 mm (0.067 inch). Rod (3) must protrude out of the top of the cylinder block.
- Dimension (A) is 50.75 mm (1.9980 inch) and dimension (B) is 9.35 mm (0.3681 inch). Dimension (A) and dimension (B) are tangential to the cylinder bore (4).
- The position of the rod (3) must be within dimension (C). Dimension (C) is 10 mm (0.3937 inch).
Note: Ensure that the rod (3) can not damage the piston cooling jet when the alignment is checked. The piston cooling jets can not be adjusted. If a piston cooling jet is not in alignment the piston cooling jet must be replaced.
Perkins 1104D EURO 3 Service Repair Manual
Cold Start Advance Unit: The cold start advance unit holds the timing of the fuel injection pump in an advance position when the engine is cold. The coolant switch for the cold start advance unit is on the water temperature regulator housing on the left side of the engine.
When the engine is cold, the sender unit is energized in order to advance the fuel injection pump timing for the cold start operation. When the correct temperature is achieved the sender unit is de-energized and the fuel injection pump timing is returned to the normal operating position.
If the switch fails in the closed position, the engine will run with advanced fuel injection timing. The engine will have higher cylinder pressure and engine damage may result.