[tylertyler]

Hello,

I changed the front brake pads of my f30 320i. I noticed some brake fluid leak under my car on driver's side.

I did not remove/open this Brake fluid container at any time and I figured that when I used a clamp to push the calliper pistons in, that pressure must have pushed the brake fluid out of the brake fluid container.

I tried to drive a couple of miles, seems the brake is working fine but feels softer than before.

I am worried that the pressure of pushing the callipers broke some seals/hoses. any thoughts, please?

thanks

[Djphonics]

I would suggest doing an inspection of the seals on the calipers. Last thing you want is brake fluid dripping on your rotor whilst loosing pressure in the system.

[tylertyler]

i see, thanks!

[Shirazkhan]

If the brake fluid came from the reservoir then that was when you pushed the piston back and thats normal.

[tylertyler]

Originally Posted by Shirazkhan

If the brake fluid came from the reservoir then that was when you pushed the piston back and thats normal.

ok, so it that how brake fluid reservoir design like this, to leak overfilled fluid? i do see there were leak around reservoir, it seems like from seal of reservoir. but no more new leak found, and car brake is working fine. thanks again

[Shirazkhan]

Yeah just throw water around that area were the brake fluid leaked.Or it might remove the paint from the brake booster.

[Shirazkhan]

Its not from the seal of the reservoir,if it is then its not normal.It came out the top where the cap fits,which is fine.You can always mark and note the level of the fluid.

[tylertyler]

Originally Posted by Shirazkhan

Its not from the seal of the reservoir,if it is then its not normal.It came out the top where the cap fits,which is fine.You can always mark and note the level of the fluid.

got it, thank you!

[casualDIYer]

Originally Posted by Shirazkhan

Yeah just throw water around that area were the brake fluid leaked.Or it might remove the paint from the brake booster.

Definitely follow this guy's advice. Brake fluid will dissolve paint. Clean up spills with water ASAP.

[casualDIYer]

Originally Posted by tylertyler

ok, so it that how brake fluid reservoir design like this, to leak overfilled fluid? i do see there were leak around reservoir, it seems like from seal of reservoir. but no more new leak found, and car brake is working fine. thanks again

The reservoir is pretty much the flimsiest part of the brake system as you can take the cap off with a turn of a cap. Any other place in the brake system,including the caliper, lines, ABS pump, or master cylinder, is significantly more difficult as you need tools. You can replace the reservoir cap if the seal is faulty. That would be part 34336851090 - BMW Brake Fluid Reservoir Tank Cover Filler Cap. Inside the cap is a gasket that, like all gaskets, wears over time. The big surprise here is the price. It's $13, from the dealer.

If you can operate a pop bottle, you're qualified for this repair.