Modifying the Air Shutoff Valve{1078, 1078} Caterpillar

Modifying the Air Shutoff Valve{1078, 1078}

Usage:

Engine:: 3508 (S/N: 8TL1-UP); 3508B (S/N: CBB1-UP; S2B1-UP; S2D1-UP; S2E1-UP; S2F1-UP; BAG1-UP; 2BM1-UP; 7SM1-UP; 1TW1-UP; 2HW1-UP; 3DW1-UP; BPX1-UP; 1FZ1-UP; CNB1-UP; 6PN1-UP; S2A1-UP; LPD1-UP; 3DM1-UP; 5PS1-UP; CTC1-UP); 3512B (S/N: S2J1-UP; S2K1-UP; S2L1-UP; S2M1-UP; 7HM1-UP; 8EM1-UP; BRN1-UP; 4TN1-UP; 1PW1-UP; 2GW1-UP; 4AW1-UP; 5AW1-UP; 2EZ1-UP; CTB1-UP; CTH1-UP; BRC1-UP; 2AF1-UP; 4DR1-UP; 3ZW1-UP; NSC1-UP; FFG1-UP); 3516B (S/N: CBN1-UP; 8CN1-UP; 8KN1-UP; 9AN1-UP; S2R1-UP; 2FW1-UP; 3CW1-UP; 4BW1-UP; S2X1-UP; CTA1-UP; 1NW1-UP; LEK1-UP; CTJ1-UP)
Pumper:: SPF343 (S/N: 6RZ1-UP); SPT343 (S/N: 5XZ1-UP)

Introduction

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

The limit switches are being relocated to a position that will improve the service life of the limit switches and of the air shutoff valve.

Also, A vibration damper has been added to the air shutoff valve. The vibration damper is installed in the original location of the limit switch.

Note: New limit switches must be used in this conversion. The new switches have normally closed contacts. The old switches have normally open contacts.

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Illustration 1	g01201688
Former location of the limit switch

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Illustration 2	g01304161
New location of the limit switch and of the vibration damper (1) 263-2905 Limit Switch As (2) 289-8498 Air Shutoff Damper Gp

System Operation

The new switches for the air shutoff valves are normally closed switches. The new switches are in the closed state when the gates for the air shutoff valves are latched in the OPEN position. If the air shutoff valve is in the CLOSED position, the new switches are in the open state. This will cause an emergency stop condition. The engine will also shut down. This also prevents the engine from starting.

Conversion Procedure

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Table 1
Required Parts ⁽¹⁾
Quantity	Part Number	Description	Torque
2	263-2905	Limit Switch As	16 ± 3 N·m (142 ± 27 lb in)
2	272-7102	Cap
2	289-8498	Air Shutoff Damper Gp
4	4P-8134	Clip
4	0S-1588	Bolt	47 ± 9 N·m (353± 7 lb ft)
8	9X-6772	Cable Strap

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^( 1 )

Quantity that is required for one engine

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Illustration 3	g01201758
(1) 227-7483 Limit Switch As

Disconnect both switches (1) from the engine wiring harness.

Remove switches (1) from both of the air shutoff valves.
Switches (1) will not be reused.

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Illustration 4	g01304165
(2) 289-8498 Air Shutoff Damper Gp

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Illustration 5	g01304171

Install damper (2) into the threaded hole.

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Table 2
Parts for the 289-8498 Damper
Item	Part Number	Description
3	288-2766	Housing
4	288-2767	Spring
5	288-2768	Plunger
6	3J-1907	O-Ring Seal
7	9S-8004	Plug

ReferenceRefer to Special Instruction, REHS3005 for the inspection and maintenance instructions for the damper.

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Illustration 6	g01304174
(8) 215-2705 Cap

Remove cap (8) .
The fasteners will be reused. Cap (8) will not be reused.

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Illustration 7	g01304179
(9) 263-2905 Limit Switch As (10) 272-7102 Cap (11) 4P-8134 Clips (12) 0S-1588 Bolts

Install cap (10) with the fasteners that were used to secure cap (8). Use 4C-5598 High Temperature Anti-Seize on the threads. Torque the fasteners to 7 ± 1 N·m (62 ± 9 lb in).

Install switches (9) .
Note: Do not apply an excessive amount of anti-seize compound. Anti-seize compound in the switch can cause the switch to fail.
Use 4C-5598 High Temperature Anti-Seize on the threads. Torque the switches to 16 ± 3 N·m (142 ± 27 lb in).

Connect switches (9) to the engine wiring harness.

Install clips (11) with bolts (11) .
Torque bolts (12) to 47 ± 9 N·m (35 ± 7 lb ft).

Use 9X-6772 Cable Straps to secure the wiring harness to clips (11) .
Note: Ensure that the vent holes on the limit switch assembly are covered if the air shutoff valve is repainted. This will prevent paint from entering the switches. Ensure that the vent holes are free of debris after the air shutoff valve is repainted.

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Illustration 8	g01304185
Typical example (13) Harness for the solenoid (14) Harness for the new limit switch

Secure harness (14) for the new limit switch onto harness (13) for the solenoid.
Ensure that the wiring harness is not touching the exhaust manifold or the shielding for the exhaust manifold.

Perform the operational test.

Operational Test

Before putting the engine back into service, perform the following operational test on the air shutoff system. This test will verify that the system is functioning properly.

Verify that the gates for both air shutoff valves are in the open position and that both of the limit switches are connected.

Turn the power for the engine control panel to the ON position.
Both of the gates for the air shutoff valves should remain open. If the gates did not remain open, check the wiring for the limit switches.

Repeat Step 2 until both of the gates remain open.

Verify that the power for the engine control panel is in the ON position.

Activate the emergency stop button.
Both of the gates for the air shutoff valves should close. If both gates did not close, check the wiring for the limit switches and the wiring for the solenoid.

Repeat Step 5 until both of the gates close when the emergency stop button is activated.

Turn the power for the engine control panel to the OFF position.

Reset the emergency stop button to the RUN position.

Set the gate for only the right side air shutoff valve to the OPEN position.

Turn the power for the engine control panel to the ON position.
The gate for the right side air shutoff valve should close. If the gate for the right side air shutoff valve is closed, proceed to Step 12. If the gate for the right side air shutoff valve did not close, check the wiring for the right side limit switches and the wiring for the right side solenoid.

Repeat Steps 7 through 10 until the gate for the right side air shutoff valve closes.

Turn power for the engine control panel to the OFF position.

Reset the emergency stop button to the RUN position.

Set the gate for only the left side air shutoff valve to the OPEN position.

Turn the power for the engine control panel to the ON position.
The gate for the left side air shutoff valve should close. If the gate for the left side air shutoff valve is closed, the system is working correctly. If the gate for the left side air shutoff valve did not close, check the wiring for the left side limit switches and the wiring for the left side solenoid.