Vacuum leak around master brake cylinder

freakystyly · 09-22-2020, 11:52 AM

https://www.realoem.com/bmw/enUS/sho...diagId=34_1481

So I've been experiencing a hard brake pedal to the point it has become hard all the time even with the car running. There is a noticeable hissing coming from the master cylinder area.

I will try replacing the check valve and gasket before other things. (#11, #4 in the diagram) But the sound seems to be coming from inside the cylinder, is that possible? I'm not knowledgeable to the workings of the cylinder.

Thanks

freakystyly · 09-24-2020, 08:30 PM

Man, what a pain in the butt this job is with a LHD car. The DIY was for a RHD and made it sound very doable..

Does anyone have any advice for replacing the gasket?... preferably without dropping it into the void? I've already dropped an extension down there and had to fish it out with a magnet for what seemed like 4 hours.

I tried the fish hook wire method to line things up but am still having a hard time prying the gasket into its lip. There simply is no room for tools besides a flat head from above.

Loosening the DSC unit only allows about 1/4" play because everything in there is hard lined on this thing. Is it OK to remove the lines on the DSC unit and remove it or would that cause further problems?

09-22-2020, 11:52 AM	#1
freakystyly Lieutenant Colonel 2978 Rep 1,794 Posts Drives: F22 B58 6MT Join Date: May 2016 Location: Ontario iTrader: (0)	Vacuum leak around master brake cylinder https://www.realoem.com/bmw/enUS/sho...diagId=34_1481 So I've been experiencing a hard brake pedal to the point it has become hard all the time even with the car running. There is a noticeable hissing coming from the master cylinder area. I will try replacing the check valve and gasket before other things. (#11, #4 in the diagram) But the sound seems to be coming from inside the cylinder, is that possible? I'm not knowledgeable to the workings of the cylinder. Thanks
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09-24-2020, 08:30 PM	#2
freakystyly Lieutenant Colonel 2978 Rep 1,794 Posts Drives: F22 B58 6MT Join Date: May 2016 Location: Ontario iTrader: (0)	Man, what a pain in the butt this job is with a LHD car. The DIY was for a RHD and made it sound very doable.. Does anyone have any advice for replacing the gasket?... preferably without dropping it into the void? I've already dropped an extension down there and had to fish it out with a magnet for what seemed like 4 hours. I tried the fish hook wire method to line things up but am still having a hard time prying the gasket into its lip. There simply is no room for tools besides a flat head from above. Loosening the DSC unit only allows about 1/4" play because everything in there is hard lined on this thing. Is it OK to remove the lines on the DSC unit and remove it or would that cause further problems?
	Appreciate 0 Quote