Check changeover of radiator for exhaust gas recirculation

Special tools and workshop equipment required

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Hand vacuum pump, e.g. -VAS 6213-

Work procedure

The vacuum setting element for change-over flap is accessible from below.

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Remove the sound dampening system → Body Work; Rep. gr.50.

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Unbolt heat shield for right drive shaft.

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Detach vacuum hose from vacuum setting element.

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Connect hand vacuum pump to vacuum setting element.

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Actuate the hand vacuum pump in order to generate negative pressure.

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The vacuum setting element must open the change-over flap up to the stop at maximum 0.08 MPa (0.8 bar) negative pressure and in case of ventilation close it up to the stop -arrows-.

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For this test the opening of the change-over flap can be performed in jolts. In driving mode the change-over flap opens suddenly due to the large negative pressure volume.

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The closing of the change-over flap must be carried out suddenly when ventilating (e.g. detach vacuum hose).

If the vacuum setting element does not open or close the change-over flap up to the stop:

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Replace radiator for exhaust gas recirculation with vacuum setting element → Chapter.