Installation and Removal of the 443-5682 Pressure Sensor Gp (In Cylinder Pressure Sensor) {1250, 1439, 1439} Caterpillar

Engine

3512B (S/N: ED31-UP; S2G1-UP; PPH1-UP)

3516B (S/N: FF21-UP; LY31-UP; LY41-UP; F4H1-UP; YAT1-UP; YAW1-UP)

Off-Highway Truck/Tractor

785C (S/N: 1HW1-UP; APX1-UP)

Introduction

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Safety Section

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Hot parts or hot components can cause burns or personal injury. Do not allow these parts to contact your skin. Let the engine cool down before performing maintenance on or around the engine.

Required Tools

Note: The 478-3965 Sensor Harness As can be replaced if damaged during installation and removal.

Removal Procedure

Illustration 1	g06147949
(1) 443-5682 Pressure Sensor Gp (In Cylinder Pressure Sensor)

Illustration 2	g06148758
(1) 443-5682 Pressure Sensor Gp (In Cylinder Pressure Sensor)

1. Allow engine to cool down, or wear appropriate personal protective equipment to avoid burns.

2. Disconnect the battery.
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   Illustration 3	g06155337
   (A) Area around the sensor (1) 443-5682 Pressure Sensor Gp (In Cylinder Pressure Sensor) (2) 478-3965 Sensor Harness As

3. Clean area around the sensor (A) before removing sensor harness (2) to avoid liquid or debris from getting into the harness connector or the sensor. Clean area with compressed air or vacuum. Do not exceed 689 kPa (100 psi) compressed air.

4. Inspect area around the sensor (A) to ensure that the area is free of debris that could fall into the combustion chamber.

5. Remove sensor harness (2) from pressure sensor (1). Pull from the round connector. Do not pull on the wires. Do not twist the round connector. There are no locking tabs to release. If desired, use a spark plug wire pliers or hose grip pliers to assist connector removal.

6. Loosen pressure sensor (1) using a ratchet, a 12 mm 6-Point Deep Socket, and extensions (if necessary). Finish unthreading by hand. Do not use an impact wrench.

7. Insert the 9U-7067 Tapered Cap/Plug into the sensor port to prevent debris from falling into combustion chamber.

Installation Procedure

Illustration 4	g06155342
(A) Area around the sensor (B) Port threads (C) Port surface (D) Sensor seat

1. Inspect area around the sensor port (A) to ensure that the area is free of debris that could fall into the combustion chamber.

2. If using previously removed cylinder heads, remove the 9U-7067 Tapered Cap/Plug from the sensor port.

3. Inspect port threads (B) to ensure that the threads are free of any debris. If cylinder heads were delivered with Tarp or Tarp-B applied, clean per the Engine News, SEBD9204, Uses, Characteristics, And Removal of Castrol Tarp®, Tarp-B®, And 4164® prior to installing on the engine. If the heads were delivered with a different rest preventer applied, clean appropriately prior to installing on the engine.

   Note: If the engine and DGB retrofit kit is going to be painted, ensure that all sensors, actuators, and wiring harnesses are installed and connected or ensure that any open holes or exposed connectors are fully masked. Paint in port threads will affect the sensor's tightening torque. Paint inside connectors may prevent a good electrical connection.

4. Clean port threads (B) and port surfaces (C) with the 264-4355 Nylon Brush to ensure that cleaning agent removes tarp in the cylinder pressure sensor threads. Do not use metal brushes. Any tarp left in the threads will affect the cylinder pressure sensor's tightening torque.

5. Clean sensor seat (D) with the 266-2281 Nylon Brush to ensure that cleaning agent removes tarp from the cylinder pressure sensor seat. Do not use metal brushes. Any tarp left on the seat may cause premature sensor failure because of combustion gas leakage.

6. Inspect sensor seat (D) to ensure that the seat is free of debris. It is important for the sensor seat to be clean so the sensor seals to the cylinder head. A poor seal at this location may cause premature sensor failure because of combustion gas leakage.

7. Use shop air to blow out the port in the cylinder head.
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   Illustration 5	g06155337
   (A) Area around the sensor (1) 443-5682 Pressure Sensor Gp (In Cylinder Pressure Sensor) (2) 478-3965 Sensor Harness As

8. Clean the threads of pressure sensor (1) with nylon brush. Do not use steel or brass brushes.

9. Inspect pressure sensor (1). Ensure all surfaces and the connector are free of debris, liquid, or damage.

10. Lightly apply anti-seize to pressure sensor threads. Use Loctite C5-A / Loctite 8008 or equivalent copper-based anti-seize.

11. Hand-tighten sensor into port until seated. Use caution to avoid cross-threading. Do not use an impact wrench. Use caution to keep the pressure sensor tip from contacting any hard surfaces during installation.

12. If sensor resists hand-tightening, chase port threads (B) in the cylinder head with a 4C-5894 Tap (M10 x 1). Contain metal debris using a small magnet and/or vacuum. Repeat steps 4 through 12.

13. Tighten sensor to 11.5 ± 1 N·m (102 ± 9 lb in) using a torque wrench, a 12 mm 6-Point Deep Socket, and solid extensions (if necessary). Do not use an impact wrench. Do not use flexible/universal wrenches or extensions because they reduce the torque applied to the sensor. Applying too much torque to the sensor may cause premature sensor failure.

    Note: There will be a gap between the sensor and the cylinder head because the sensor seats at the bottom of the port

14. Inspect the round connector of sensor harness (2) for liquid, debris, or damage. Clean or replace as necessary.

15. Connect sensor harness (2) to pressure sensor (1) by pushing the connector until an audible click is heard. Do not twist the round connector. A confirmation tug should be applied to verify that the connector is latched.

16. Reconnect the battery.