I try to limit myself to the "easy as changing a flat tire" type of DIY maintenance. Oil change and door seals certainly fit the bill. Today, I found that a brake flush (absent the ABS/GT1 part) does too. My sense is that these tasks are so mundane that they are ripe for sloppiness (e.g. overtightening) when left to a professional.
Timing:
Manual says once every 2yrs. I'll probably make it a routine every year at this time, when my winter wheels get swapped off for summers. I had 3 unusual complications doing this my first time. Excluding those, this job should take you 20-30mins longer than changing 4 flat tires.
Miscellany (skippable unless you enjoy a chuckle):
My complications were...
a) Not removing the lower clip on the microfilter with two hands. Murphy's Law penalized me with a drop of said clip, and a side trip to removing the lower engine shields to recover it. From above, I could not see it, to use my magnetic extractor.
b) Finding that the last person who ventured here did not remove the microfilter carefully. The rubber flap that keeps debris out of the sidewall was stripped off. A side trip with a shop vac recovered said flap from the depths.
c) Finding that the last person either semi-stripped one of my bleeder nuts (or skipped that corner after giving up). A delay, to let PB Blaster work its magic, was needed to free it. If you need to use PB, remember you are working around brake parts: guard where you spray with paper towel backing.
Needed:
Motive Power Bleeder (Euro cap, 1100), from Bimmerzone
1 container of ATE Typ200 (1L, amber), from Bimmerzone
1 magnetic catch bottle, from Bimmerzone, marked in 250mL increments with kitchen measuring cup.
small funnel
9mm crescent/box wrench, or adjustable wrench
big towel
tire changing stuff: jack, lug & torque wrench
nice to have: syringe, disposal container, nitrile gloves
Steps:
1. Disconnect hood alarm sensor, at the driver's microfilter
2. Remove driver's microfilter. Clear the 3 tabs on the left, lift the bar at the front, remove the microfilter lid, remove the lower retaining clip (use two hands!), remove microfilter housing to expose the brake fluid compartment.
3. Clean compartment, drop a towel all around this area to catch any wayward corrosive brake fluid droplets.
4. Disconnect fluid reservoir cable (level sensor).
5. Syringe out old fluid to the "min" level. I was afraid to go further (introduce air). Does anyone know how much old fluid you can safely extract?
6. Replace to "max" level with new fluid.
7. Fit Motive properly, pump to 13-15psi. Check for tight seal.
Now work from farthest wheel to closest, repeating as needed...
8. Jack and remove wheel.
9. Pop off rubber bleeder nipple cover. Be mindful of cables (driver's front, passenger's rear).
10. Seal catch can tubing completely over nipple, and position such that air is encouraged to escape upwards.
11. Loosen (counter clockwise) nipple screw to allow fluid to flow. I jostled mine a tad during flow, to loosen debris.
12. Observe level in catch can, and color quality of fluid in tubing. My fluid became clear and pretty after ~130mL.
13. Pinch off flow via screw. Repump to 15psi. Open flow for one last check and retighten. I used "finger tight plus" (less tight than the last pro who was here on my car).
14. Wipe off any drizzle/drops of brake fluid around the caliper.
15. Top fluid reservoir back to "max" anytime it's near "min".
...
Last. Top fluid level. Put humpty dumpty back together again.
My guess at total fluid used: 500mL in catch bottle + 3x60mL syringe extract + 150mL final top off = approx. 850mL
Timing:
Manual says once every 2yrs. I'll probably make it a routine every year at this time, when my winter wheels get swapped off for summers. I had 3 unusual complications doing this my first time. Excluding those, this job should take you 20-30mins longer than changing 4 flat tires.
Miscellany (skippable unless you enjoy a chuckle):
My complications were...
a) Not removing the lower clip on the microfilter with two hands. Murphy's Law penalized me with a drop of said clip, and a side trip to removing the lower engine shields to recover it. From above, I could not see it, to use my magnetic extractor.
b) Finding that the last person who ventured here did not remove the microfilter carefully. The rubber flap that keeps debris out of the sidewall was stripped off. A side trip with a shop vac recovered said flap from the depths.
c) Finding that the last person either semi-stripped one of my bleeder nuts (or skipped that corner after giving up). A delay, to let PB Blaster work its magic, was needed to free it. If you need to use PB, remember you are working around brake parts: guard where you spray with paper towel backing.
Needed:
Motive Power Bleeder (Euro cap, 1100), from Bimmerzone
1 container of ATE Typ200 (1L, amber), from Bimmerzone
1 magnetic catch bottle, from Bimmerzone, marked in 250mL increments with kitchen measuring cup.
small funnel
9mm crescent/box wrench, or adjustable wrench
big towel
tire changing stuff: jack, lug & torque wrench
nice to have: syringe, disposal container, nitrile gloves
Steps:
1. Disconnect hood alarm sensor, at the driver's microfilter
2. Remove driver's microfilter. Clear the 3 tabs on the left, lift the bar at the front, remove the microfilter lid, remove the lower retaining clip (use two hands!), remove microfilter housing to expose the brake fluid compartment.
3. Clean compartment, drop a towel all around this area to catch any wayward corrosive brake fluid droplets.
4. Disconnect fluid reservoir cable (level sensor).
5. Syringe out old fluid to the "min" level. I was afraid to go further (introduce air). Does anyone know how much old fluid you can safely extract?
6. Replace to "max" level with new fluid.
7. Fit Motive properly, pump to 13-15psi. Check for tight seal.
Now work from farthest wheel to closest, repeating as needed...
8. Jack and remove wheel.
9. Pop off rubber bleeder nipple cover. Be mindful of cables (driver's front, passenger's rear).
10. Seal catch can tubing completely over nipple, and position such that air is encouraged to escape upwards.
11. Loosen (counter clockwise) nipple screw to allow fluid to flow. I jostled mine a tad during flow, to loosen debris.
12. Observe level in catch can, and color quality of fluid in tubing. My fluid became clear and pretty after ~130mL.
13. Pinch off flow via screw. Repump to 15psi. Open flow for one last check and retighten. I used "finger tight plus" (less tight than the last pro who was here on my car).
14. Wipe off any drizzle/drops of brake fluid around the caliper.
15. Top fluid reservoir back to "max" anytime it's near "min".
...
Last. Top fluid level. Put humpty dumpty back together again.
My guess at total fluid used: 500mL in catch bottle + 3x60mL syringe extract + 150mL final top off = approx. 850mL
