Stiff Brake Pedal at Startup

bpwj76 · 05-25-2023, 02:41 PM

I have a 2016 SDrive28i with 110k miles. Recently, I'd say within the past two weeks or so, when going to start the vehicle it has a very stiff brake pedal and I get a message in the instrument cluster that I need to press the brake pedal first to start the car. Then after pressing the pedal even harder I feel a slight click in the pedal and the car starts. Normal feeling brake pedal returns once the car starts.

Any ideas as to what could be causing this behavior?

bpwj76 · 05-26-2023, 08:00 AM

I think I may have a vacuum leak.

slowblackx3f25 · 05-26-2023, 11:00 AM

it would throw a code.

whens the last time you did a brake fluid flush and refill as well as bleed the brake lines?
this must be done every two years...

rcsup1 · 05-26-2023, 02:37 PM

I have had the same issue for a while now. I definitely think its a vacuum leak from the brake booster. Have really looked into it. Could be the booster or possibly a one-way check valve that leads to the booster.

HighlandPete · 05-26-2023, 04:53 PM

Quote:

Originally Posted by bpwj76

I think I may have a vacuum leak.

Yes, sign of a vacuum leak. Not uncommon to have a firmer brake pedal at the first start, if a vehicle is not used for several days. If it is frequent, definitely get it sorted.

05-25-2023, 02:41 PM	#1
bpwj76 Private First Class 94 Rep 184 Posts Drives: 2021 530i; 2016 X3 Sdrive28i Join Date: Oct 2018 Location: Louisiana iTrader: (0)	Stiff Brake Pedal at Startup I have a 2016 SDrive28i with 110k miles. Recently, I'd say within the past two weeks or so, when going to start the vehicle it has a very stiff brake pedal and I get a message in the instrument cluster that I need to press the brake pedal first to start the car. Then after pressing the pedal even harder I feel a slight click in the pedal and the car starts. Normal feeling brake pedal returns once the car starts. Any ideas as to what could be causing this behavior?
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05-26-2023, 08:00 AM	#2
bpwj76 Private First Class 94 Rep 184 Posts Drives: 2021 530i; 2016 X3 Sdrive28i Join Date: Oct 2018 Location: Louisiana iTrader: (0)	I think I may have a vacuum leak.
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05-26-2023, 11:00 AM	#3
slowblackx3f25 xdriv33 69 Rep 218 Posts Drives: 17' BMW x3 F25 xDrive28i xLine Join Date: Aug 2019 Location: Toronto, Ontario, Canada iTrader: (0) Garage List 2017 BMW x3 [0.00]	it would throw a code. whens the last time you did a brake fluid flush and refill as well as bleed the brake lines? this must be done every two years...
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05-26-2023, 02:37 PM	#4
rcsup1 Second Lieutenant 154 Rep 221 Posts Drives: x3 35i Join Date: Jun 2015 Location: West Miramar/South Florida iTrader: (0)	I have had the same issue for a while now. I definitely think its a vacuum leak from the brake booster. Have really looked into it. Could be the booster or possibly a one-way check valve that leads to the booster. __________________ 2011 F25 X3 35i \|M-Sport Front Bumper Conversion\|Largus Full Adjustable Coilovers\|FTP Charge Pipes\|Gutted Catalytic Downpipe\|RB Oil Cooler Thermostat Delete\|25 Row Oil Cooler\|Custom Built Cold Air Intake\|9"AEM Cone Filter Behind Kidney Grills With Outerwear\|Precision Raceworks Coils\|BM3 Stage 2 E30 Tune\| BM3 Upgraded 8-speed TCU Flash\|395mm X5M Front Brakes
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