RING-RETAINING 3W2025 - Caterpillar

Jake Brake Compression Brake Adjustment
Illustration 1 g01102453
Typical configuration for Jake Brake's engine compression brake
(1) Slave piston adjustment screw
(2) Slave piston
(3) Exhaust valve rocker arm
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
BXS1-01546
Jake Brake 340C All ratings 0.89 0.08 mm (0.035 0.003 inch)
BXS01547-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.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.
Loosen the locknut and back out slave piston adjustment screw (1) until the slave piston is not in contact with exhaust valve rocker arm (3).
Insert the appropriate feeler gauge between the foot of the slave piston (2) and the exhaust valve rocker arm. Refer to Table 1 for the correct slave piston lash setting.
Turn the slave piston adjustment screw in a clockwise direction until the slave piston tightens against the feeler gauge. Tighten the adjustment 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.
Slowly turn the slave piston adjustment 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.
Tighten the locknut to a torque of 34 5 N m (25 4 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