Continue applying vaccum and filling the reservior until the fluid being extracted is clear.
[B][COLOR="Red"]DO NOT[/COLOR][/B] let the fluid get too low as this will allow air into the system and you have a lot more work ahead of you to clear it
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Continue applying vaccum and filling the reservior until the fluid being extracted is clear.
[B][COLOR="Red"]DO NOT[/COLOR][/B] let the fluid get too low as this will allow air into the system and you have a lot more work ahead of you to clear it
Clean fluid being extracted from reservior, compare fluid color difference with picture above.
At this point - secure bleed nipple and if the reservoir is low put enough fluid in to ensure there is no chance of air getting into the system.
[B]DO NOT FILL TO THE TOP [/B]- the next steps involve opening up the brake pads - this will force fluid up into the reservior - if it is full you will have a mess. As a point of interest the above pictures shows how much fluid I had when I secured the reservoir nipple.
NOTE - the tightening torque for the reservoir nipple is 2Nm - I set it hand tight.
[B]FLUID REPLACEMENT RIGHT/LEFT CALIPER[/B]
The next steps in fluid replacement for the front brakes are to replace the fluid in the calipers and lines.
To do this BMW uses some really cool tools to push back and hold the pads open to push out the fliud.
If interested the tool part numbers are 341531 and 341532 - as I have no intention of getting these tools, I subsituted by removing the calipers to push back and hold the pads in place.
To remove the calipers use a T-45 Torx.
Remove the two bolts highlighted below:
Once the screws are out you can remove the caliper by twisting the caliper so that the pads can be spread a little using the disc.
You do not have to twist too much - just enough to spread the pads to clear the disc and remove.
Now you need to pry back the pads.
I used my hi-tech 6" straight slot screwdriver - use what ever you are comfortable with.
The next step is to hold the pads back in place., starting with the Right side caliper
I was able to use a 3/8" drive extension (the socket male end) to fit in nicely without damaging the pad.
Please note that this may not work all the time depending on pad thickness due to wear - in that case you need to solve that problem.
Double check the level of fluid in the reservoir - if getting too high get rid of some because you need to do the same thing to the left side caliper
Do the same for the left side.
[B]PROCESS NOTE -[/B] please note that the ABS sensor cable is attached to the left brake line.
The is no need to remove it - just be aware it is there
Left caliper held open
Now that both calipers are held open you can begin vaccum bleeding the caliper.
The set up I used is shown below.
You will need an 8mm wrench for the caliper nipple.
FLUID REPLACEMENT PROCESS -
1 - Remove fluid from reservoir on handle bar and replace with new fluid
2 - connect vaccum device to bleed nipple
3 - open bleed nipple and start vaccum
4 - check fluid level in reservoir - do not allow to drain completely
5 - continue steps 3 and 4 until clear fluid is being extracted.
6 - close off bleed nipple
7 - top off reservoir
Repeat for other side
PROCESS NOTE 1 - as a personal preference I remove the rubber nipple covers to be able to properly access the nipple.
PROCESS NOTE 2 - the standard tubing included with the Mighty Vac - fit ok onto the nipple but not snugly enough to prevent asmall amount air leakage - when extracting the fluid there were some bubbles noted in the stream. For next fluid replacement I will get some smaller tubing for a snugger fit. The tubing ID use on the front reservior was too small for use on the caliper nipple.
The set up for the left caliper.
Repeat process again
FLUID REPLACEMENT PROCESS -
1 - connect vaccum device to bleed nipple
2 - open bleed nipple and start vaccum
3 - check fluid level in reservoir - do not allow to drain completely
4 - continue steps 3 and 4 until clear fluid is being extracted.
5 - close off bleed nipple
After mount the calipers back onto the fork tubes.
After mounting the right and left caliper torque the bolts to 30 Nm.
At this point we need to prepare for a manual bleed.
1 - with both calipers properly mounted and torqued squeeze the front brake lever repeatedly until the brake pads make contact with the disc.
[B]MAINTAIN [/B]a close eye on the fluid level in the reservoir to ensure it does not go too low.
The manual bleed set up I used is shown below
[B]Front Brake Manual Bleed[/B]
The closing portion is to do a manual bleed of the front brake at the caliper - this is to ensure no air managed to enter the system during vacuum evacuation.
[B][COLOR="Blue"]Process for [B]Right Side Manual Bleed[/B][/COLOR][/B]
1 - Pump lever a few times (3 to 4 times should be enough) until you have solid resistance.
2 - while maintaining pressure on the lever - open the bleed screw slightly - and observe color of fluid being expelled
3 - tighten the bleed screw [B][COLOR="Red"]BEFORE LETTING GO OF THE LEVER [/COLOR][/B]- I can not stress this enough as there is a potential for air injestion.
4 - Repeat steps 1-3 until clear fluid is extracted - please keep an eye on your reservior fluid level.
NOTE - It took me 3 repeats of the above steps to get clear liquid - this is not to say to do it only 3 times, but rather it did not take many repetitions to achieve the desired results.
[B][COLOR="Blue"]Process for [B]Left Side Manual Bleed[/B][/COLOR][/B]
Note - it is extremely helpful to have an assitant support you in this actiity - they can do the hand lever and watch the fluid level, while you do the bleeding at the caliper.
1 - Pump lever a few times (3 to 4 times should be enough) until you have solid resistance.
2 - while maintaining pressure on the lever - open the bleed screw slightly - and observe color of fluid being expelled
3 - tighten the bleed screw [B][COLOR="Red"]BEFORE LETTING GO OF THE LEVER [/COLOR][/B]- I can not stress this enough as there is a potential for air injestion.
4 - Repeat steps 1-3 until clear fluid is extracted - please keep an eye on your reservior fluid level.
NOTE - It took me 3 repeats of the above steps to get clear liquid - this is not to say to do it only 3 times, but rather it did not take many repetitions to achieve the desired results.
[B]Close off caliper bleed screws.[/B] - BMW stated torque is 5Nm - I did them hand tight
Bleed Nipple Cover Installion
If you did not remove the bleed nipple covers continue directly to the Final Reservoir Fill
Else see below:
The nipple cover has a small rubber ring which fits onto a groove in the bleed nipple.
Slightly over stretch the circular portion of cover and fit it over the nipple onto the groove.
Do not over stretch as it can break