CONTROL GP-ENGINE ELECTRONIC 1546713 - Caterpillar

Illustration 1 g00501265
Compression brake (1) Control valve (2) Lead wire (3) Bolt assembly (4) Slave piston (5) Solenoid valve (6) Master piston (7) Stud and nutThe compression brake consists of three identical housing assemblies. A housing assembly is installed in each of the valve mechanism compartments above the rocker arms and above the rocker arm shaft. Each housing assembly is positioned over two cylinders. The housing assembly is mounted to the supports for the rocker arm shaft with studs and nuts (7). The housing assemblies are supported on the cylinder head with bolt assembly (3). The exhaust bridge assembly is used to transfer force from slave piston (4) to the exhaust valve. The brake logic signal for the compression brake is carried to solenoid valve (5) by lead wire (2). This is done in order to activate the compression brake on the two cylinders of the engine.A spacer is used on the top of the valve cover base in order to provide space for the installation of the compression brake and of the valve cover. When the compression brake is installed, the height increases approximately 63.5 mm (2.50 inch).The control circuit for the compression brake permits the operation of either one, two, or all three of the compression brake housing assemblies. This provides progressive braking capabilities with the retarding effect of two cylinders, of four cylinders, or of all six cylinders in the engine.Performance of the Compression Brake
Illustration 2 g00427859
Performance of the compression brakeThe performance of the compression brake, which is shown in the graph, represents an engine with the three housing assemblies that are activated in order to stop the vehicle. The compression brake should not be activated when the engine rpm is above 2300. The maximum engine power rating is 2100 rpm. At this level, the amount of braking that is produced by the compression brake is approximately 315 to 325 horsepower.Operation of the Compression Brake
Illustration 3 g00501985
Schematic for master-slave circuit (1) Rocker arm shaft oil passage (2) Solenoid valve (3) Lead wire (4) Spring (5) Control valve (6) High pressure oil passage (7) Slave piston adjustment screw (8) Master piston (9) Engine oil pump (10) Spring (11) Engine oil pan (12) Fuel injector rocker arm (13) Fuel injector pushrod (14) Slave piston (15) Oil drain passage (16) Low pressure oil passage (17) Ball check valve (18) Exhaust valve rocker arm (19) Exhaust valve (20) Exhaust bridge assemblyThe compression brake is operated by engine oil that is distributed around the studs. This oil is supplied through the supports for the rocker arm shaft. Solenoid valve (2) controls the oil flow in the compression brake housing.When the solenoid is activated by a signal from the logic for the compression brake, solenoid valve (2) moves downward. This causes oil drain passage (15) to engine oil pan (11) to be closed. At the same time, low pressure oil passage (16) to control valve (5) is opened. As low pressure oil passage (16) is filled with engine oil, the control valve is pushed