Inlet Throttle (ILT) Valve (Emission control - Td5)

The EGR valve is a cast and machined assembly which locates on the front end of the inlet manifold assembly. The machined faces of the EGR assembly and the inlet manifold are attached together using four screws passing through the four corners of a flange in the EGR assembly to tappings in the front face of the inlet manifold. A gasket is used to seal the interface between the EGR valve and the front face of the inlet manifold. The gasket should be changed every time the EGR valve assembly is removed from the air intake manifold.

The intake side of the EGR valve allows the passage of fresh intercooled air through to the inlet manifold via a rubber hose which is attached to the front face of the EGR valve assembly by a metal band clamp. The bottom port of the EGR valve is connected to the EGR pipe using a metal band clamp.

A vacuum port on top of the EGR valve connects to the EGR modulator through a blue, small-bore suction hose. When a vacuum is applied to the EGR valve suction port it causes a spindle with sealing disc (EGR valve) to be raised, thereby opening the port at the EGR pipe to allow the recirculated exhaust gas to pass through into the inlet manifold. When the vacuum is removed from the suction port the EGR valve returns to its rest position under the influence of a spring to tightly close the exhaust gas port. Thus controlled opening of the EGR valve determines the mass of recirculated exhaust gas allowed to flow through to the inlet manifold.

Inlet Throttle (ILT) Valve

1 EGR valve vacuum port 2 EGR valve assembly 3 Gasket – EGR valve to inlet manifold 4 ILT valve vacuum port 5 ILT valve 6 EGR pipe connection

7 Exhaust gas intake 8 ILT valve – butterfly 9 Intake air 10 EGR valve open (vacuum applied to EGR valve; ILT valve butterfly shown fully open) 11 EGR valve closed (no vacuum to EGR valve; ILT butterfly valve shown fully open)