testing vanos oil pressure accumulator

[foler]

How to test working condition vanos oil pressure accumulator? His function is to buffer and supply oil under high pressure to vanos system.

Part number 9 for m3 e36 here:
http://bmwfans.info/parts/catalog/E36/Coupe/Europe...

or on e46 model m3 part number 4:
http://bmwfans.info/parts/catalog/E46/Coupe/Europe...