89 750iL intermittent air pumping sound under hood around PS reservior

[sinc750]

Hello I'm new to the forum and very thankful for the information I've already found out about my 1989 750iL. I recently acquired the car after being stored a long time. Now it has a few bugs that need to be worked out from sitting. The car has low miles, 52K miles and is mostly stock except for wheels and stereo. Currently I'd please like some help with a pumping/air leak noise coming from under the hood right around the PS / load leveling reservoir. You can hear it inside the car as well. Makes a similar sound to intermittent wipers going on and off. I've uploaded a video to YouTube with the sound and showing the one hose/pipe moving. It's very consistent. Any suggestions are appreciated. I've checked the reservoir level and it's about 3/4 full. Here is the link to the video:

https://youtu.be/_uBRlwPnjAQ

Thanks for your time.
Sinc

[shogun]

That kind of silicone hose seen there moves when the noise comes. Where is that coming from and going to? Not original, my car does not have that.

[sinc750]

Thanks. I will take a closer look at the hose and also compare it to my 1992 car and update the thread. BTW I used your magic reset on my 1992 and it's been running perfectly for over a month now! Much appreciated.

[shogun]

1992 might have ASC+T and your 1989 probably not, the system looks different then https://www.realoem.com/bmw/enUS/par...MW-750iL&mg=32
but in the youtube it looks like an open non hydraulic hose and on my car there is no such hose in that area.