IDENTIFICATION The air compressor, with a power-steering pump attached, is driven by a gear on the camshaft. Exhaust Brake/Constant-Throttle Valves The engine is cooled by a closed system using recirculated coolant; temperature is regulated automatically by a thermostat. To increase braking performance, the engine is equipped with an exhaust brake on the turbocharger in conjunction with constant-throttle valves on the cylinder head. See Figure 7. There are two main drive belts, each with its own automatic belt tensioner. The alternator and coolant pump (and any other accessories) and the refrigerant compressor are driven by a main drive belt. The fan is driven by its own drive belt NOTE:
On EGR engines, the constant-throttle valves are activated by engine oil pressure. Electrical equipment includes a starter and an alternator. The exhaust back pressure is used by the exhaust brake to increase braking performance. Figure 7 Constant-Throttle Activation (shown with EGR system removed) 16 All information subject to change without notice. (Rev. 04/08) DDC-SVC-MAN-0056 04/08 Copyright © 2008 DETROIT DIESEL CORPORATION