Brake Leak around Rear Diff. Causes?

IanMan · 06-08-2017, 08:11 AM

Hey all. I've been steadily losing brake fluid and finally found the location but am not able to get my car on a lift any time soon. The brake fluid is leaking around my rear diff and I am not sure if this is a common occurrence or what I should first expect to be wrong once I get under the car. Has anyone had this problem before, and what did it end up being? Thanks!

msan · 06-08-2017, 08:45 AM

There are two short brake lines with connectors in the mid. Here's a post showing where they are and how to change them out. You might be leaking there.

http://www.e90post.com/forums/showpo...1&postcount=17

Redd · 06-08-2017, 10:28 AM

I had a brake fluid leak at the two short hoses near the rear diff. They were steel braided hoses. Suspect the rear subframe movement was pulling on the short hoses and damaged them. Problem was fixed by putting in slightly longer hoses.

roastbeef · 06-11-2017, 08:36 PM

Quote:

Originally Posted by msan

There are two short brake lines with connectors in the mid. Here's a post showing where they are and how to change them out. You might be leaking there.

http://www.e90post.com/forums/showpo...1&postcount=17

this is what i was thinking.

IanMan · 06-21-2017, 09:50 AM

Yep! you guys are right. It's gotta be back there. Thanks a lot for the posts!

IanMan · 11-27-2019, 08:11 AM

Hey guys. I ordered the new brake lines. I cannot seem to find where these are located on the M3. Maybe I didn't lift the car high enough to see where they are, but I am not seeing it. Does anyone know the exact location on the M3? Thanks!

DRLane · 11-27-2019, 09:11 AM

Quote:

Originally Posted by IanMan

Hey guys. I ordered the new brake lines. I cannot seem to find where these are located on the M3. Maybe I didn't lift the car high enough to see where they are, but I am not seeing it. Does anyone know the exact location on the M3? Thanks!

See attached

IanMan · 11-27-2019, 09:17 AM

Quote:

Originally Posted by DRLane

See attached

DUDE! THANK YOU!

On a side note, can I reach those without removing the rear diff? Thanks again!

Ian

DRLane · 11-27-2019, 09:20 AM

Quote:

Originally Posted by IanMan

Quote:

Originally Posted by DRLane

See attached

DUDE! THANK YOU!

On a side note, can I reach those without removing the rear diff? Thanks again!

Ian

Yes, without issue. Jack up the rear of the car 20". Easily accessible. Note you'll want stubbie wrenches as it's a tight fit. Good luck!

pbonsalb · 11-27-2019, 12:05 PM

I found changing those lines to braided to be a lot of work. 1/4 turn often seemed like great progress. My diff and axles were in place.

06-08-2017, 08:45 AM	#2
msan Major 403 Rep 1,171 Posts Drives: 2011 E90 M3 / 2012 X5 35i M Sp Join Date: May 2015 Location: Los Angeles, CA iTrader: (16)	There are two short brake lines with connectors in the mid. Here's a post showing where they are and how to change them out. You might be leaking there. http://www.e90post.com/forums/showpo...1&postcount=17
	Appreciate 0 Quote

06-08-2017, 10:28 AM	#3
Redd Brigadier General 3898 Rep 4,163 Posts Drives: 2010 BMW E92 M3 Dakar Edition Join Date: Jul 2015 Location: Malaysia iTrader: (0)	I had a brake fluid leak at the two short hoses near the rear diff. They were steel braided hoses. Suspect the rear subframe movement was pulling on the short hoses and damaged them. Problem was fixed by putting in slightly longer hoses.
	Appreciate 0 Quote

11-27-2019, 12:05 PM	#10
pbonsalb Lieutenant General 5231 Rep 10,614 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	I found changing those lines to braided to be a lot of work. 1/4 turn often seemed like great progress. My diff and axles were in place.
	Appreciate 1 IanMan384.00 Quote