3406E Truck Engines Caterpillar


Compression Brake

Usage:

3406E 1LW

------ WARNING! ------

The Electronic Control Module produces high voltage. To prevent personal injury make sure the Electronic Control Module is not powered and do not come in contact with the fuel injector solenoid terminals while the engine is running.


------ WARNING! ------

This engine uses high voltage to control the fuel injectors.

Disconnect the fuel enable circuit connector to prevent personal injury.

Do not come in contact with the fuel injector terminals while the engine is running.


The engine valve lash and the injector lash must be within specifications prior to adjusting the compression brake's slave piston lash. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure for inspection of the engine valve lash. Refer to Testing and Adjusting, "Electronic Unit Injector - Adjust" for the proper procedure for inspection of the injector lash adjustment.

Note: The slave piston lash adjustment must be performed while the engine is cold. If the engine is warm, allow the engine to cool prior to performing the following adjustments.

Use the following procedure to adjust the slave piston lash on cylinders 1, 3, and 5:

Put the No. 1 piston at the top center position on the compression stroke. See Testing and Adjusting, "Finding Top Center Position for No. 1 Piston" for further details.

Jake Brake Compression Brake Adjustment



Illustration 1g00596577
Typical configuration for Jake Brake's engine compression brake
(1) Slave piston adjusting screw
(2) Slave piston
(3) Rocker arm


NOTICE

Prior to adjusting the lash setting for the engine compression brake, check the identification plate that is on the compression brake's casting in order to determine the model that is installed on your engine. You must have this model number and the engine's serial number prefix in order to determine the lash setting for your engine.


Table 1
Slave Piston Lash Setting
Jake Brake Compression Brakes 
Serial Number Prefix and Model Number(1)  Horsepower Rating  Slave Piston Lash Setting 
2WS1-UP
6NZ1-UP
Jake Brake 340C 
410 hp or less  0.94 ± 0.08 mm (0.037 ± 0.003 inch) 
435 hp or more 0.84 ± 0.08 mm (0.033 ± 0.003 inch) 
375/435 hp Multitorque rating 0.84 ± 0.08 mm (0.033 ± 0.003 inch) 
1MM1-UP
7CZ1-UP
5DS1-UP
Jake Brake 340C 
All ratings  0.94 ± 0.08 mm (0.037 ± 0.003 inch) 
1LW1-UP
Jake Brake 340C 
410 hp or less  0.84 ± 0.08 mm (0.033 ± 0.003 inch) 
435 hp or more 0.68 ± 0.08 mm (0.027 ± 0.003 inch) 
5EK1-UP(2)
6TS1-UP
Jake Brake 340A 
410 hp or less  0.68 ± 0.08 mm (0.027 ± 0.003 inch) 
435 hp or more 0.76 ± 0.08 mm (0.030 ± 0.003 inch) 
5EK1-UP(2)
Jake Brake 340 
435 hp or more  0.68 ± 0.08 mm (0.027 ± 0.003 inch) 
1LW1-UP
6NZ1-UP
7CZ1-UP
Jake Brake 340D 
All ratings  0.64 ± 0.08 mm (0.025 ± 0.003 inch) 
CJP1-UP
MDP1-UP
MEP1-UP
W1A1-UP
Jake Brake 340C 
All ratings  1.02 ± 0.08 mm (0.040 ± 0.003 inch) 
MBN1-UP
Jake Brake 340D 
All ratings  0.76 ± 0.08 mm (0.030 ± 0.003 inch) 
BXS1-UP
Jake Brake 340C 
All ratings  0.89 ± 0.08 mm (0.035 ± 0.003 inch) 
BXS1-UP
Jake Brake 340E 
All ratings  0.84 ± 0.08 mm (0.033 ± 0.003 inch) 
(1) Check the identification plate that is on the compression brake's casting in order to determine the model that is installed on your engine.
(2) Some of the early 3406E Engines 5EK1-01820 were built with either the 340 or the 340A compression brakes.

Note: The slave piston lash settings are specific to the model number of the compression brake and to the serial number prefix of the engine. Use these settings only for the compression brakes and serial number prefixes that are specified in the table.

340D Compression Brakes

  1. Loosen adjustment locknut (1) and back out the adjusting screw until the slave piston is not in contact with the exhaust valve rocker arm.

  2. Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 1 for the correct slave piston lash setting.

  3. Turn the slave piston adjusting screw in a clockwise direction until the slave piston tightens against the feeler gauge. A slight drag should be felt on the feeler gauge.

  4. Tighten the adjustment locknut (1) to a torque of 35 N·m (25 lb ft). Recheck the adjustment after you tighten the locknut. If necessary, repeat this procedure.

340, 340A, 340B, 340C, and 340E Compression Brakes

  1. Loosen adjustment locknut (1) and back out the adjusting screw until the slave piston is not in contact with the exhaust valve rocker arm.

  2. Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 1 for the correct slave piston lash setting.

  3. Turn the slave piston adjusting screw in a clockwise direction until the slave piston tightens against the feeler gauge. Tighten the adjusting screw for one additional turn in the clockwise direction. The valve spring should start to compress. Allow the oil to be purged from the autolash assembly of the compression brake for 30 seconds.

    Note: All of the oil must be allowed to drain from the compression brake's autolash assembly. If the temperature of the oil is below 16 °C (60 °F), allow the oil to be purged for an additional two minutes. Serious engine damage may occur if the oil is not properly purged from the autolash assembly.

  4. Slowly turn the adjusting screw counterclockwise until the slave piston begins to loosen against the feeler gauge. A slight drag should be felt on the feeler gauge when the adjustment is correct.

    Note: Do not overshoot the setting of the slave piston during adjustment. If you overshoot the setting, you must repeat this procedure.

  5. Tighten the adjustment locknut (1) to a torque of 35 N·m (25 lb ft). Recheck the adjustment after tightening the locknut. If necessary, repeat the procedure.

Adjust the slave piston lash settings for cylinders 3 and 5 prior to rotating the engine.

After you adjust cylinders 1, 3, and 5, reset the timing pin and turn the flywheel for 360 degrees in the direction of the engine's rotation. This will position the No. 6 piston at the top center on the compression stroke. Ensure that the timing pin has located the timing hole that is in the flywheel.

Continue to perform the adjustment procedure for the slave piston lash settings on cylinders 2, 4, and 6.

Remove the timing pin from the flywheel after all adjustments have been performed. Reinstall the timing cover.

Pacbrake Compression Brake Adjustment



Illustration 2g00975814
Typical configuration for Pacbrake's engine compression brake
(1) Slave piston adjusting screw
(2) Slave piston
(3) Rocker arm

Table 2
Slave Piston Lash Setting
Pacbrake Compression Brakes 
Serial Number Prefix  Model Designation  Slave Piston Lash Setting 
5EK1-UP
6TS1-UP
1LW1-UP
5DS1-UP
2WS1-UP
1MM1-UP
6NZ1-UP
7CZ1-UP  
P39A or P39B  0.76 ± 0.08 mm (0.030 ± 0.003 inch) 
6NZ1-UP
7CZ1-UP  
P39C  Product Campaign(1) 
MBN1-UP   P39D  0.97 ± 0.08 mm (0.038 ± 0.003 inch) 
BXS1-UP   P39E  0.71 ± 0.08 mm (0.028 ± 0.003 inch) 
(1) Contact Pacbrake for information that relates to the product campaign.

Note: The slave piston lash settings are specific to the serial number of the engine. Ensure that the slave piston lash setting that is being used is correct for the serial number of your engine.

P39A Compression Brakes

  1. Loosen adjustment locknut (1) and back out the adjusting screw until the slave piston is not in contact with the exhaust valve rocker arm.

  2. Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 2 for the correct slave piston lash settings.

  3. Turn the slave piston adjusting screw in a clockwise direction. Tighten the slave piston adjusting screw beyond the point of contact with the exhaust valve rocker arm. This will allow the oil to be purged from the slave piston. Once the oil has been purged from the piston, turn the slave piston adjusting screw in a counterclockwise direction until the feeler gauge is loose between the adjusting screw and the rocker arm.

  4. Again, turn the slave piston adjusting screw in a clockwise direction until a slight drag is felt on the feeler gauge.

  5. Tighten the adjustment locknut (1) to a torque of 35 N·m (25 lb ft).

Adjust the slave piston lash settings for cylinders 3 and 5 prior to rotating the engine.

P39B, P39D, and P39E Compression Brakes

  1. Loosen adjustment locknut (1) and back out the adjusting screw until the slave piston is not in contact with the exhaust valve rocker arm.

  2. Insert the appropriate feeler gauge between the foot of the slave piston (2) and the rocker arm (3). Refer to Table 2 for the correct slave piston lash settings.

  3. Turn the slave piston adjusting screw in a clockwise direction until the slave piston tightens against the feeler gauge. Tighten the adjusting screw for one additional turn in the clockwise direction. The valve spring should start to compress. Allow the oil to be purged from the components of the compression brake for 1 minute.

  4. Slowly turn the adjusting screw counterclockwise until a slight drag is felt on the feeler gauge.

    Note: Do not overshoot the setting of the slave piston during this adjustment. If you overshoot the setting, you must repeat this procedure.

  5. While you hold the screw of the adjuster, tighten the adjustment locknut (1) to a torque of 35 N·m (25 lb ft).

    Note: Do not place excessive torque on the locknut that is on the adjusting screw. If excessive torque is placed on the adjustment screw, damage to the components of the compression brake may result.

  6. Recheck the adjustment after tightening the locknut. If a slight drag is not felt on the feeler gauge, repeat the adjustment procedure.

Adjust the slave piston lash settings for cylinders 3 and 5 prior to rotating the engine.

After you adjust cylinders 1, 3, and 5, reset the timing pin and turn the flywheel for 360 degrees in the direction of the engine's rotation. This will position the No. 6 piston at the top center on the compression stroke. Ensure that the timing pin has located the timing hole that is in the flywheel.

Continue to perform the adjustment procedure for the slave piston lash settings on cylinders 2, 4, and 6.

Remove the timing pin from the flywheel after all adjustments have been performed. Reinstall the timing cover.

Oil Pressure Test for Jake Brake Compression Brakes

Ensure that the engine oil pressure is within the correct operating range before performing any tests on the compression brake. Low engine oil pressure can cause weak braking or no braking at all. High engine oil pressure may cause the compression brake not to operate at all. Refer to the Testing and Adjusting, "Lubrication System" topic for more information.

To properly troubleshoot the compression brake, the technician must know the oil pressure reading at the compression brake housings. The oil pressure reading on the oil pressure gauge in the instrument panel does not provide the same information as the oil pressure reading at the compression brake housings.

Low oil pressure in the compression brake housings may cause weak braking or no braking at all. If the oil pressure in the compression brake housings is too high, the compression brake may not operate at all. High oil pressure may also prevent the compression brake from shutting off.

Oil Pressure Test at Control Valve

------ WARNING! ------

Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.


Table 3
Tools Needed 
Part Number  Part Name  Quantity 
149-6111  Oil Pressure Test Kit 


Illustration 3g00527135

  1. Assemble pressure gauge (1), control valve body (4), and control valve adapter (5). Hand tighten the adapter assembly.

  2. While the engine is not running, remove the control valve. Refer to Disassembly and Assembly for more information.


    Illustration 4g00521294

  3. Insert the adapter assembly into bore (7) for the control valve. Hold the assembly approximately 3.175 mm (0.1250 inch) above the bottom of the bore in order to allow the oil to enter the adapter.

  4. Start the engine. Ensure that the compression brake switch is in the OFF position.


    Illustration 5g00521295

  5. Hold the adapter assembly in place and depress solenoid armature (8). Record the oil pressure reading.

    Note: Hold the solenoid on only long enough to obtain the oil pressure reading. The oil pressure may be too low at idle in order to operate the compression brake. This condition is normal.

  6. Increase the engine speed by 400 rpm.

  7. Repeat Steps 5 and 6 up to the rated engine rpm.

  8. Stop the engine. Install the control valve. Refer to Disassembly and Assembly for more information.

    The oil pressure readings above 1000 rpm should be 380 ± 205 kPa (55 ± 30 psi).

    If the oil pressure readings are too low, proceed to "Oil Pressure Test at Solenoid Valve".

    If the oil pressure readings are too high in the compression brake housings, the engine oil pressure is too high. Refer to the Testing and Adjusting, "Lubrication System" topic for more information.

Oil Pressure Test at Solenoid Valve

------ WARNING! ------

Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.


Table 4
Tools Needed 
Part Number  Part Name  Quantity 
149-6111  Oil Pressure Test Kit 


Illustration 6g00527135

  1. Attach pressure gauge (1) to solenoid valve adapter (6).

  2. Remove the solenoid valve and the three seals from the compression brake housing. Refer to Disassembly and Assembly for more information.

  3. Install three new seals (2). Place the smallest seal in the bottom of the bore for the solenoid. Install the other two seals on solenoid valve adapter (6).


    Illustration 7g00521296

  4. Lubricate the seals with clean engine oil and install the adapter assembly in bore (7) for the solenoid valve. Hand tighten the adapter assembly and then tighten the adapter assembly for an additional 1/4 turn.

  5. Start the engine. Ensure that the compression brake switch is in the OFF position.

  6. Record the oil pressure reading.

  7. Increase the engine speed by 400 rpm.

  8. Repeat Steps 6 and 7 up to the rated engine rpm.

  9. Stop the engine. Install the solenoid valve. Refer to Disassembly and Assembly for more information.

    Compare the oil pressure readings from the solenoid valve to the oil pressure readings from "Oil Pressure Test at Control Valve". If the oil pressure at the solenoid valve is higher than the oil pressure at the control valve, continue with Steps 10 through 15.

  10. Start the engine.

  11. Disconnect the wires from each solenoid valve except for the solenoid valve that is being tested in order to check each solenoid valve individually.


    Illustration 8g00521295

  12. Turn the compression brake switch to the ON position. Observe the movement of solenoid armature (8). The solenoid armature should snap down fully. Push down on the solenoid armature in order to verify that the solenoid is fully actuated.

    If the solenoid valve fully actuates, proceed to Step 14. Otherwise, continue to Step 13.

  13. Check the voltage at the terminals on the solenoid valve. There should be at least ten volts at the terminals.

    Insufficient voltage at the terminals indicates that there is either poor connections in the circuit or that the battery voltage is low. Verify proper battery voltage. Check the condition of the connections and clean the connections.

    Replace the solenoid valve if both of the following conditions exist:

    • The solenoid valve is receiving the correct voltage.

    • The solenoid valve does not actuate fully.

  14. Look for excessive oil leakage from the bottom of the compression brake housing opposite the solenoid valve. While the solenoid valve is electrically actuated, leakage should be no more than two drops per second. Replace the solenoid valve if there is excessive leakage.

    Note: When the solenoid valve is deactivated, oil will dump from the solenoid valve. This is a normal condition that should not be confused with oil leakage while the solenoid valve is electrically actuated.

  15. Repeat Steps 11 through 14 for each solenoid valve.
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