Air cleaner

Air cleaner assembly	removal and refitting
Removal
	Slacken and remove the three screws securing the air cleaner assembly to the throttle body (see illustration).
	Lift up the assembly, then disconnect the wiring connector from the air temperature sensor, and the inlet manifold vacuum pipe from the thermac valve (see iliustrations).
	Remove the air cleaner assembly, and recover its sealing ring from the throttle body flange.
Refitting
	Refitting is the reverse sequence to removal, ensuring that the sealing ring is correctly located on the throttle body flange.
Air cleaner air temperature control system - informaion, testing and component renewal
General information
	The system is controlled by a thermac valve/switch mounted in the air cleaner assembly; when the engine is started from cold, the switch is closed, to allow inlet manifold depression to act on the air temperature control valve in the inlet duct. This raises a vacuum diaphragm in the valve assembly, and draws a flap valve across the cold air inlet, thus allowing only (warmed) air from the exhaust manifold to enter the air cleaner.
	As the temperature of the exhaust-wamed air in the air cleaner rises, a bi-metallic strip in the thermac switch deforms, opening the switch to shut off the depression in the air temperature control valve assembly. The flap is lowered gradually across the hot air inlet until, when the engine is fully warmed-up to normal operating temperature, only cold air from the front of the inlet duct is entering the air cleaner.
Testing
	To check the system, allow the engine to cool down completely, then unclip the inlet duct from the air cleaner body; the flap valve in the duct should be securely seated across the hot air inlet. Staff the engine; the flap should immediately rise to close off the cold air inlet, and should then lower steadily as the engine warms up, until it is eventually seated across the hot air inlet again.
	To check the thermac switch, disconnect the vacuum pipe from the control valve when the engine is running, and place a finger over the pipe, and when the engine is cold, full inlet manifold vacuum should be present in the pipe, and when the engine is at normal operating temperature, there should be no vacuum in the pipe.
	To check the air temperature control valve, unclip the inlet duct from the air cleaner body; the flap valve should be securely seated across the hot air inlet. Disconnect the vacuum pipe, and suck hard at the control valve stub; the flap should rise to shut off the cold air inlet.
	If either component is faulty, it must be renewed as described below.
Component renewal
Thermac switch
	Remove the air cleaner assembly as described in Section 2.
	Release the lid retaining clips, then remove the lid and withdraw the air cleaner filter element.
	Disconnect the vacuum pipe (see illustration), then bend up the tags on the switch clip. Remove the clip, then withdraw the switch and its seal,
	Refitting is the reverse sequence to removal, ensuring that the switch mating surfaces are clean, and that the switch and seal are correctly located before fastening the clip
Air temperature control valve
	Disconnect the vacuum pipe from the valve, then unclip the inlet duct from the air cleaner and remove it from the engine compartment.
	The air temperature control valve can be renewed only with the complete inlet duct assembly. If a new inlet duct assembly is being fitted, undo the three screws securing the hot air inlet adapter plate to the bottom of the duct, and transfer the adapter plate to the new duct (see illustration).
	Clip the duct into position in the air cleaner, and reconnect the vacuum pipe.