Audi Workshop Service and Repair Manuals > A4 Mk3 > Power unit | 6-cylinder direct petrol injection engine (3.2 ltr. 4-valve), mechanics | Exhaust system | Secondary air system - country-specific version 1 | Checking combination valves for secondary air system for correct operation and leakage

Checking combination valves for secondary air system for correct operation and leakage

Procedure

l	No leaks in hose connections.

–	Remove plenum chamber partition panel → Rep. Gr.50.

Combination valve for secondary air system (right-side):

–	Move fuel line -1- and line -2- (leading to activated charcoal filter) clear at air pipe.

–	Disconnect vacuum hose -3- from connection on air pipe.

–	Remove air pipe. To do so, release hose clip -4- and clamps -arrows-.

Continuation for both sides:

–	Remove bolts -2- and press secondary air hoses to side.

Note

Disregard -item 1-.

–	Connect suitable hose -arrow- to combination valve for secondary air, as shown in illustration.

–	Blow lightly into test hose with your mouth (do not use compressed air).

l	The combination valve for secondary air system should be closed; it should not be possible to blow through the hose.

–	Blow more firmly (i.e. with greater pressure) into test hose with your mouth (do not use compressed air).

l	The combination valve for secondary air system should open; it should now be possible to blow through the hose.

–	Renew combination valve for secondary air system if you cannot determine the switching point: (left-side) → Chapter, (right-side) → Chapter

Assembling

Installation is carried out in the reverse order; note the following:

Note

t	Hose connections and air pipes and hoses must be free of oil and grease before assembly.

t	Secure all hose connections with the correct type of hose clips (same as original equipment) → Electronic parts catalogue.

t	To ensure that the air hoses can be properly secured at their connections, spray rust remover onto the worm thread of used hose clips before installing.

–	Install plenum chamber partition panel → Rep. Gr.50.

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