Bmw N52 stiff brake pedal and no vaccum???

alamara967 · 11-11-2020, 03:30 PM

Hello everyone this is my first time posting on a forum so if i’m doing something incorrect im very sorry but i have a 2007 bmw 328i with the N52 motor. one day i was driving and my brake pedal went very stiff and i could barely stop. a few moments later it went back to normal. later that day the brake pedal went stiff again and did not go back to normal. i went under the hood and located my vaccum line from the vaccum pump going to the brake booster. i started the engine and took off the vaccum line only to realize there is no vaccum what so ever even with the engine started. there is a very slight vaccum but it is very slight. i took apart the vaccum line and made sure it had no cracks or leaks. Could this be my vaccum pump located under the intake headers? i have no idea where to start or what tests i can do. there is very little to none vaccum going to the brake booster. please help!!!

relative4 · 11-11-2020, 05:43 PM

If there is little or no vacuum at the pump with the pipe completely removed, then the pump diaphragm is probably shot. Is there oil in the pipe?

alamara967 · 11-11-2020, 05:58 PM

Quote:

Originally Posted by relative4

If there is little or no vacuum at the pump with the pipe completely removed, then the pump diaphragm is probably shot. Is there oil in the pipe?

There is alittle bit of oil in the pipe near the vaccum pump but it’s not a lot. Where should i go on from here? Do i replace the vaccum pump itself? a shop near me quoted me $1100 and i don’t think it’s worth it. i might DIY it but i don’t see any videos or threads explaining how to replace it myself. the vaccum pump is connected to the timing chain so i don’t think it’s going to be easy. my only issue is i don’t know if it is truly the vaccum pump or the brake booster?

relative4 · 11-11-2020, 09:46 PM

Have you removed the entire pipe and tested vacuum at the pump?

alamara967 · 11-15-2020, 04:50 PM

Quote:

Originally Posted by relative4

Have you removed the entire pipe and tested vacuum at the pump?

Yes i have, very little vaccum at the pump

relative4 · 11-16-2020, 07:32 AM

Well then, sounds like you need a new vacuum pump.
$1100 is very reasonable. If you want to DIY it, you can save some money, but it is not a job for beginners.

11-11-2020, 03:30 PM	#1
alamara967 New Member 0 Rep 6 Posts Drives: bmw 328i Join Date: Nov 2020 Location: michigan iTrader: (0)	Bmw N52 stiff brake pedal and no vaccum??? Hello everyone this is my first time posting on a forum so if i’m doing something incorrect im very sorry but i have a 2007 bmw 328i with the N52 motor. one day i was driving and my brake pedal went very stiff and i could barely stop. a few moments later it went back to normal. later that day the brake pedal went stiff again and did not go back to normal. i went under the hood and located my vaccum line from the vaccum pump going to the brake booster. i started the engine and took off the vaccum line only to realize there is no vaccum what so ever even with the engine started. there is a very slight vaccum but it is very slight. i took apart the vaccum line and made sure it had no cracks or leaks. Could this be my vaccum pump located under the intake headers? i have no idea where to start or what tests i can do. there is very little to none vaccum going to the brake booster. please help!!!
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11-11-2020, 05:43 PM	#2
relative4 Major 611 Rep 1,272 Posts Drives: '08 335xi E90 MT stage 1+ Join Date: Feb 2019 Location: Denver, CO iTrader: (0)	If there is little or no vacuum at the pump with the pipe completely removed, then the pump diaphragm is probably shot. Is there oil in the pipe?
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11-11-2020, 09:46 PM	#4
relative4 Major 611 Rep 1,272 Posts Drives: '08 335xi E90 MT stage 1+ Join Date: Feb 2019 Location: Denver, CO iTrader: (0)	Have you removed the entire pipe and tested vacuum at the pump?
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11-16-2020, 07:32 AM	#6
relative4 Major 611 Rep 1,272 Posts Drives: '08 335xi E90 MT stage 1+ Join Date: Feb 2019 Location: Denver, CO iTrader: (0)	Well then, sounds like you need a new vacuum pump. $1100 is very reasonable. If you want to DIY it, you can save some money, but it is not a job for beginners.
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