Brake pedal very soft, goes to the floor

phillyg! · 09-14-2024, 12:07 PM

Apologies if there are other threads on this issue, wanted to list what I have done to my car specifically.

2011 328i E90

A few months ago, I replaced both front rotors. Yesterday, I replaced both front calipers and reinstalled the relatively new pads.
I bled all 4 calipers starting from the furthest from the master cylinder. Brake pedal was firm after the bleeding. When I start the car, the brake pedal is very soft and the brakes don’t engage until the pedal is essentially at the floor.
I replaced my calipers with new because my brake pedal was soft and I suspected bad piston, but the pedal is softer now.
Bad master cylinder? Any ideas?

Thank you

Phil

bosstones · 09-14-2024, 12:33 PM

Is the brake fluid reservoir still full (or ar least however full you left it after the bleed procedure)? Or have you checked signs of brake fluid leaks/weeps?

New calipers (vs rebuilt) from a reputable shop?

phillyg! · 09-14-2024, 12:36 PM

Brake fluid level did decrease after the bleeding, I filled it back up. No sings of leaking that I have seen. They are the higher rated new calipers from rockauto

lordnikon · 09-14-2024, 03:18 PM

Did you make sure there's no air in the lines?

09-14-2024, 12:07 PM	#1
phillyg! New Member 1 Rep 11 Posts Drives: 2011 bmw 328i Join Date: Apr 2024 Location: 85140 iTrader: (0) Garage List 2011 bmw 328i [0.00] 2011 [0.00] [0.00] 2011 [0.00]	Apologies if there are other threads on this issue, wanted to list what I have done to my car specifically. 2011 328i E90 A few months ago, I replaced both front rotors. Yesterday, I replaced both front calipers and reinstalled the relatively new pads. I bled all 4 calipers starting from the furthest from the master cylinder. Brake pedal was firm after the bleeding. When I start the car, the brake pedal is very soft and the brakes don’t engage until the pedal is essentially at the floor. I replaced my calipers with new because my brake pedal was soft and I suspected bad piston, but the pedal is softer now. Bad master cylinder? Any ideas? Thank you Phil
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09-14-2024, 12:33 PM	#2
bosstones Lieutenant Colonel 1244 Rep 1,593 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	Is the brake fluid reservoir still full (or ar least however full you left it after the bleed procedure)? Or have you checked signs of brake fluid leaks/weeps? New calipers (vs rebuilt) from a reputable shop? __________________ - Jeff bosstones' flickr
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09-14-2024, 12:36 PM	#3
phillyg! New Member 1 Rep 11 Posts Drives: 2011 bmw 328i Join Date: Apr 2024 Location: 85140 iTrader: (0) Garage List 2011 bmw 328i [0.00] 2011 [0.00] [0.00] 2011 [0.00]	Brake fluid level did decrease after the bleeding, I filled it back up. No sings of leaking that I have seen. They are the higher rated new calipers from rockauto
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09-14-2024, 03:18 PM	#4
lordnikon Captain 524 Rep 620 Posts Drives: Break My Wallet Join Date: Feb 2023 Location: Ontario iTrader: (0) Garage List 2011 BMW 328i xDrive [0.00]	Did you make sure there's no air in the lines?
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