Attention: Do not start the engine without a vacuum pump.
Examination
Connect a vacuum gauge to the vacuum pump and start the engine.
The vacuum pump must generate a vacuum of at least 530 mbar.
Removal, model 524td
Remove cylinder head cover.
Rotate the crankshaft and thus the camshaft until the cam of the vacuum pump on the camshaft is in the lower position.
Attention: Do not turn the camshaft by the toothed pulley.
Unscrew 4 nuts and pull out the vacuum pump.
Installation
Install the vacuum pump so that the nozzle is at the back and the cam enters the recess of the pusher.
Insert sealing ring 4. First check its integrity, see also figure W - 1095.
Install the cylinder head cover; if necessary, replace the gasket.