Soft and spongy brakes - faulty master cylinder?

Thanks folks...certainly feeling like a sense of inevitability about it needing done now.

Is there anyone on this forum who lives in the North East UK in the Tyne and Wear area (I'm in Durham) that has the laptop/cable/software to help me do this? If so, please DM me.

I don't own a personal laptop as I just use my work laptop for everything, and I cannot install anything on it or even use the USB ports.

Hence, getting set up with INPA myself would not only mean buying a cable (which would be fine) but would involve the expense of a laptop too.
 
FWIW, INPA will work on fairly ancient hardware and Windows XP so almost any laptop that you can beg or borrow will run it.
 
Well worth finding yourself an old working laptop with either Windows7 or XP on it and then getting a BMW INPA package off ebay which will include the interface, cable and software. You should get yourself set up for well under £100 and be able to do fault code scans and clear codes as well as running maintenance tasks like the ABS bleeding. Just getting codes read at Garages can be expensive here in the UK and having the ability to do it yourself will save you money. Its also worth noting that INPA software can be downloaded for free on the Bimmergeeks website but you would have to source the cable and interface from ebay. I used a seller called BCables on ebay years ago who supplied a full package.
 
Hi guys,
Quick update as it has been a while, and nothing worse than an unresolved thread :)

Since my very first post, I have done the following:
i) Changed master cylinder
ii) 2 new front flexis
iii) Bled new fluid through, using manual method and pressure-bleed
iv) Fitted new Brembo front pads
v) Installed INPA onto one of the kids' laptops and ran the DSC bleed routine

Weirdly, doing the INPA routine initially made the brakes worse, the pedal feel went completely actually, but persistence and pressure bleeding brought it back again. I can only assume therefore that it was a case of air being displaced in the system as the NSF line had loads of air bubbles coming out of it afterwards.

Anyway, the Z4 went in for MOT on Friday and passed with no advisories, so I guess this means the fault is resolved. :driving:

I still do think however that there is still a better pedal feel to be had with some further persistence, so I'm going to do one final pressure-bleed using the Easibleed as I need to change the NSR nipple anyway for a new one (garage had rounded the old one off when it was 'seized'), and will see how things are after that.

If it isn't any better after one more pressure bleed, then i think it'll be a case of living with it an enjoying the summer.

Interestingly, Mat Armstrong on YouTube has had similar fun and games trying to bleed a BMW M5 too - a manual bleed and a ISTA bleed didn't work...but the Easibleed did!
 
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