Author [ES] [CA] [PL] [PT] [IT] [DE] [FR] [NL] [DK] [NO] [GR] [TR] Topic: Front Master Brake Cylinder Fill Line  (Read 634 times)

0 Members and 1 Guest are viewing this topic.

Offline VanishPoint

  • XR Junior
  • *
  • Posts: 11
  • Country: us
  • Bike: S1000XR
Front Master Brake Cylinder Fill Line
« on: September 19, 2018, 05:45:00 PM »
Hi -  I just flushed my brake system for first time  (using GS911 and performing ABS pump)  and having a fluid level issue.  When I removed the front master cylinder cap (first time) I took note of where the fluid level was.  When finished flushing system, I refilled the the master cylinder back to that level (about 1/8" from top of reservoir) where it was when I started. I then tightened the 3 top screws snug but did not to over tighten them.  When done, I noticed weeping of brake fluid though the top cover. Tightening screws a bit further did not help.  I then removed a small amount of brake fluid from the reservoir (down to about top of sight glass).  This helped but had to do it twice before weeping stopped.  There is no Maximum fluid line I can see on the front Master Brake Cylinder reservoir like there is on the rear one.  Does anyone know if a maximum  fill level line exists on the front Master brake cylinder?  I know, the there is a minimum fill line.  Thanks
« Last Edit: September 19, 2018, 05:47:39 PM by VanishPoint »

Online SimonUK

  • XR Pro
  • ***
  • Posts: 298
  • Country: us
  • Bike: S1000XR,S1000R
  • Town: Upstate, SC
Re: Front Master Brake Cylinder Fill Line
« Reply #1 on: September 19, 2018, 06:10:56 PM »
not sure if these help



Offline VanishPoint

  • XR Junior
  • *
  • Posts: 11
  • Country: us
  • Bike: S1000XR
Re: Front Master Brake Cylinder Fill Line
« Reply #2 on: September 19, 2018, 11:00:57 PM »
Very helpful, thanks.  I will say this mark is very difficult to see, even when you know what you are looking for.  The light has to hit it just right. Was this information sourced from the BMW Service Manual?  I have a MAC so can't use it.  Thanks again!

Online SimonUK

  • XR Pro
  • ***
  • Posts: 298
  • Country: us
  • Bike: S1000XR,S1000R
  • Town: Upstate, SC
Re: Front Master Brake Cylinder Fill Line
« Reply #3 on: September 20, 2018, 12:15:51 AM »
Yep, came from the BMW service DVD.

There is a Haynes manual out there as well and this says to fill 'almost' to the top of the sight glass, but do not overfill!

Online Bree

  • XR God
  • *****
  • Posts: 1731
  • Country: gb
  • Bike: S1000XR
Re: Front Master Brake Cylinder Fill Line
« Reply #4 on: March 14, 2019, 05:56:16 PM »
Even if you had over filled the reservoir, I would be very concerned if you had brake fluid leaking. As it should be a completely sealed unit.
Did you replace the diaphragm, as it is also the seal between the master cylinder and the cap. The master cylinder and cap also needs to be extremely clean before replacing and tightening.
« Last Edit: March 14, 2019, 06:01:23 PM by Bree »
Everything  Will Be Alright In The End, If Not Then Its Not The End.