Hard brake pedal

heffergm · 06-02-2010, 04:46 AM

I've noticed lately that in the morning when starting the car the brake pedal is sometimes hard as a rock, like I'd pumped the pedal with the car off first. Of course I haven't, so I'm curious as to what the deal is.

Anyone else come across this?

annsue · 06-02-2010, 05:39 AM

Yes, the same exact thing has happened to me. Seems like it started happening right after my HPFP was replaced (they put in the 943, luckily!) Did you just have your fuel pump replaced? Just curious.

heffergm · 06-02-2010, 05:43 AM

No, no new pump.

annsue · 06-02-2010, 12:42 PM

Hmmmm, I wonder what's causing this and if it's normal?

BrokenVert · 06-02-2010, 01:05 PM

Its because your brakes loose boost pressure when the engine is off...

heffergm · 06-02-2010, 01:31 PM

Quote:

Originally Posted by BrokenVert

Its because your brakes loose boost pressure when the engine is off...

Which would mean it would be the same in any of the other dozen cars with power brakes I've owned, which isn't the case. So I'm not buying that explanation.

BrokenVert · 06-02-2010, 01:43 PM

Quote:

Originally Posted by heffergm

Which would mean it would be the same in any of the other dozen cars with power brakes I've owned, which isn't the case. So I'm not buying that explanation.

Didn't mean to offend. But somebody asked this same question not to long ago and that turned out to be the answer. Sorry, but with what you wrote that's the only obvious answer.

Take the car to the dealer

:

GaryS · 06-02-2010, 01:52 PM

If I understand the OP, every car I've owned has done that once in a while.

ronster · 06-02-2010, 02:02 PM

Mine is MT. Sometimes I rolled my car out of my garage (slightly incline) without turning on the engine and I find the brake pedal is really hard after I pressed the pedal 2nd time. Both my 135i and previous Cooper did this... so BrokenVert was right... it was due to the loss of boost pressure... don't worry about it... i think this is normal..

Simsims · 06-02-2010, 02:55 PM

Quote:

Originally Posted by ronster

Mine is MT. Sometimes I rolled my car out of my garage (slightly incline) without turning on the engine and I find the brake pedal is really hard after I pressed the pedal 2nd time. Both my 135i and previous Cooper did this... so BrokenVert was right... it was due to the loss of boost pressure... don't worry about it... i think this is normal..

if there's no engine vacuum then the pedal always goes hard after one or two press.

Considering your pedal works fine during driving, probably some minor leak in the brake booster.

MikesBMW · 10-06-2010, 10:09 PM

mine just started doing this like every morning, even sometimes after the car is only parked for an hour, might go to the dealer

Gort · 10-07-2010, 12:20 PM

Quote:

Originally Posted by MB135i

mine just started doing this like every morning, even sometimes after the car is only parked for an hour, might go to the dealer

Mine was doing this so I took it to the dealer. They said they couldn't find anything wrong. Ironically it hasn't happened since then for two months. Car apparently just wanted to visit the shop.

06-02-2010, 04:46 AM	#1
heffergm Private 4 Rep 66 Posts Drives: '10 135ic Join Date: Apr 2010 Location: MA iTrader: (0)	Hard brake pedal I've noticed lately that in the morning when starting the car the brake pedal is sometimes hard as a rock, like I'd pumped the pedal with the car off first. Of course I haven't, so I'm curious as to what the deal is. Anyone else come across this?
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06-02-2010, 05:39 AM	#2
annsue Private 0 Rep 68 Posts Drives: 2008 135i convertible Join Date: Jun 2009 Location: Leesburg, VA iTrader: (0)	Yes, the same exact thing has happened to me. Seems like it started happening right after my HPFP was replaced (they put in the 943, luckily!) Did you just have your fuel pump replaced? Just curious.
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06-02-2010, 05:43 AM	#3
heffergm Private 4 Rep 66 Posts Drives: '10 135ic Join Date: Apr 2010 Location: MA iTrader: (0)	No, no new pump.
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06-02-2010, 12:42 PM	#4
annsue Private 0 Rep 68 Posts Drives: 2008 135i convertible Join Date: Jun 2009 Location: Leesburg, VA iTrader: (0)	Hmmmm, I wonder what's causing this and if it's normal?
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06-02-2010, 01:05 PM	#5
BrokenVert Resident Kerbalnaut 477 Rep 10,703 Posts Drives: Topless Brute/Hybrid Boogaloo Join Date: Apr 2009 Location: Fahrvergnügen/NY iTrader: (0)	Its because your brakes loose boost pressure when the engine is off... __________________
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06-02-2010, 01:52 PM	#8
GaryS Colonel 37 Rep 2,084 Posts Drives: 2009 135i 6MT Join Date: Feb 2010 Location: Maryland iTrader: (0) Garage List 2009 135i [6.50]	If I understand the OP, every car I've owned has done that once in a while.
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06-02-2010, 02:02 PM	#9
ronster Lieutenant 16 Rep 421 Posts Drives: 2011 1M VO Join Date: Mar 2009 Location: Toronto iTrader: (0)	Mine is MT. Sometimes I rolled my car out of my garage (slightly incline) without turning on the engine and I find the brake pedal is really hard after I pressed the pedal 2nd time. Both my 135i and previous Cooper did this... so BrokenVert was right... it was due to the loss of boost pressure... don't worry about it... i think this is normal.. __________________ 2011 1M VO stripper 2009 AW 135i M-sp (sold) 2002 SG MINI Cooper (sold)
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10-06-2010, 10:09 PM	#11
MikesBMW Banned 318 Rep 1,410 Posts Drives: X3 M40i Join Date: Jul 2010 Location: Ohio iTrader: (1) Garage List 2019 BMW X3 M40i [0.00] 2017 BMW X1 [0.00]	mine just started doing this like every morning, even sometimes after the car is only parked for an hour, might go to the dealer
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