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  #1  
Old 07-22-2018, 12:38 PM
Rombbb Rombbb is offline
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bleeding steering fluid is endless

- Disconnected bottom end of reservoir-pump hose
- Drained the system as much as possible by turning steering wheel, also with wheel on the ground to create friction to turn the torsion bar thingy in the power assist apparatus (for lack of a better word :-)
- Filled it
- Started engine and turned left and right. Was a mistake, steering wheel started vibrating and not turning frictionless as it should, probably because there was mainly air in the rack cilinder. Should have turned the wheel first without the engine and pump running.
- So did that, then started engine again, turned the wheel more, all good, topped up and turned a bit more
- Drained it and repeated all steps for the genuine fill

Now came the full bleeding, first turning wheel without engine and pump, then with engine and pump. All fine, bubbles decreased, but even after literally turning the wheel for more than an hour in all manners possible (with breaks in between, slow, fast, 10x in a row etc.) they diminished to a great degree but never fully disappeared. It are only like 3 or 4 minuscule bubbles slowly floating to the surface after yanking the wheel to full lock, but still. You would think that after literally 100 wheel rotations or something that it would simply be 100% air free.

Am not planning on swapping fluid for the next 20k miles so wanted to do it good but at one point I just stopped. Turned so much I created flat spots on the tires I guess.

Does anyone have a tip ? Or are those minuscule bubbles just how it's supposed to be and am I just being OCD ? Like the fluid is super clear and you can clearly see bottom of reservoir, but you do see tiny almost like air particles slowly floating about. Like a couple of them every some wheel turns. Super annoying :-)
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  #2  
Old 07-22-2018, 02:21 PM
joelselman joelselman is offline
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Somebody may jump in who actually knows the answer, but I'm guessing you're fine as long as the steering functions properly and is not making any noises. I don't think I've ever looked that closely after p/s repairs. I would suggest that you check the fluid level often over the near future to see if the level decreases and if it stabilizes after all your tiny bubbles disappear.

Last edited by joelselman; 07-22-2018 at 02:23 PM.
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Old 07-22-2018, 04:16 PM
Rombbb Rombbb is offline
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Quote:
Originally Posted by joelselman View Post
Somebody may jump in who actually knows the answer, but I'm guessing you're fine as long as the steering functions properly and is not making any noises. I don't think I've ever looked that closely after p/s repairs. I would suggest that you check the fluid level often over the near future to see if the level decreases and if it stabilizes after all your tiny bubbles disappear.
Thanks. System itself seems tight. Steering solid, no noises, no leaks.

Thing is when putting on the cap I doubt those air particles flow to the surface as they do in open atmosphere without the cap on. So then they maybe remain where they are now in the piping until the next service.

I'm also sure I'm fine, but it's just that the service interval is so long on this fluid I'd like to do it as well as possible. Draining all air should also make steering most responsive I guess.

Of course tiny air 'droplets' are not the end of the world, but I'm just wondering were they come from and if there is some bulb of air hiding out somewhere :-)

You'd think that in such a relatively small closed circuit it'd be easy to bleed 100% in a short time, and for 90% that's true, just getting to 100% seems hardly doable.

Probably will just leave it, but maybe someone else also noticed them, shining a flashlight in the reservoir just after yanking the steering wheel.

I just don't understand why these systems aren't made easier to service. You can't even drain the system without unhooking hoses.
For example there is also conflicting info on the correct level; Pelican states that Max level should only be done with a hot engine because apparently the level rises when engine gets hot. So when cold they state you have to hit a cm below Max. I would say that the BMW engineers accounted for that assuming that majority will renew fluids with a cold engine and that Max also applies when cold.

Anyhows, these little things really make it confusing and hard to get 100% comfort of a job correctly done, without shifting to wades of forum posts trying to pinpoint the best way.

Not that I don't like browsing the forums

Last edited by Rombbb; 07-22-2018 at 04:17 PM.
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Old 07-22-2018, 06:00 PM
wifesauto wifesauto is online now
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close the hood.......you are done......find a movie on tv
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Old 07-23-2018, 08:55 AM
joelselman joelselman is offline
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Cap is vented to atmosphere.
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Old 07-23-2018, 01:26 PM
Rombbb Rombbb is offline
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Originally Posted by joelselman View Post
Cap is vented to atmosphere.
Ah ok, didn't know that.
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Old 07-25-2018, 07:28 AM
Rombbb Rombbb is offline
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Originally Posted by wifesauto View Post
close the hood.......you are done......find a movie on tv
You're right, I got carried away
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