E90Post
 


VIBE Motorsports
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > Technical question about abs bleeding and closed systems



Reply
 
Thread Tools Search this Thread
      02-17-2013, 09:08 AM   #1
ashmostro
Lieutenant Colonel
ashmostro's Avatar
United_States
20
Rep
1,758
Posts

 
Drives: '13 335is DCT
Join Date: Jan 2013
Location: Vienna, VA

iTrader: (9)

Technical question about abs bleeding and closed systems

I was thinking about this recently when I bled my abs module using the poor man's method (no INPA here). My question is, if you necessarily need a method to "open" the abs module in order to bleed out trapped air, why then would trapped air in the module even contribute to a soft pedal under normal use? Succinctly, if the fluid and any air in the module is hermetically isolated from the rest of the system until activated, shouldn't a system's pedal feel not be influenced at all by the module under normal braking?
Appreciate 0
      02-17-2013, 02:27 PM   #2
HP Autosport
BimmerPost Supporting Vendor
United_States
418
Rep
11,443
Posts


 
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, Brembo, GIAC, Koni, Ohlins, Performance Friction, Quaife, Stoptech, Vorshlag

iTrader: (29)

Quote:
Originally Posted by ashmostro View Post
I was thinking about this recently when I bled my abs module using the poor man's method (no INPA here). My question is, if you necessarily need a method to "open" the abs module in order to bleed out trapped air, why then would trapped air in the module even contribute to a soft pedal under normal use? Succinctly, if the fluid and any air in the module is hermetically isolated from the rest of the system until activated, shouldn't a system's pedal feel not be influenced at all by the module under normal braking?
How did you introduce air into your ABS unit? The only way to bleed the ABS unit properly is using activation of the motors and pumps. The poor man's method can only bleed air out of the lines, hoses and calipers.
Appreciate 0
      02-17-2013, 03:19 PM   #3
ashmostro
Lieutenant Colonel
ashmostro's Avatar
United_States
20
Rep
1,758
Posts

 
Drives: '13 335is DCT
Join Date: Jan 2013
Location: Vienna, VA

iTrader: (9)

Slippery road, brake hard, engage abs. Return to base, bleed. Big bubbles come out about forty seconds into the bleed (freshly bleed before already).

Not a glamorous as using INPA, but it worked.
Appreciate 0
      02-19-2013, 06:14 AM   #4
ashmostro
Lieutenant Colonel
ashmostro's Avatar
United_States
20
Rep
1,758
Posts

 
Drives: '13 335is DCT
Join Date: Jan 2013
Location: Vienna, VA

iTrader: (9)

No answers to the core question at hand here though? Anyone want to opine?

cheers!
Appreciate 0
      02-22-2013, 01:54 PM   #5
ashmostro
Lieutenant Colonel
ashmostro's Avatar
United_States
20
Rep
1,758
Posts

 
Drives: '13 335is DCT
Join Date: Jan 2013
Location: Vienna, VA

iTrader: (9)

Oh well, guess not. Darn.
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:56 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST