looking for a brake master cylinder for my 91 850i e31

[anovaso]

Looking for a brake master cylinder for my 91 850i.
I just bought this beauty for a hell of a deal. My dream car finally! But with a catch of course.
I bought this from a distressed wife who knew nothing about this amazing white sharknosed beast, just that she wanted it gone.
Before the husband disappeared from the scene the car was running fine according to the wife, but for some reason he decided there was a problem with the abs unit /braking system?...and basically removed the abs control unit and brake master cylinder for repair/replacement? Car was left like this for 7-8 months in the garage , then put up for sale recently and thus how I came to acquire it. Car has 136k on clock and v12 is healthy and starts right up perfectly, all cylinders have great compression, just no brakes, not even the handbrake works!! I just took possession of this car last week and all I got from the wife was the replacement "used"abs unit bought and shipped from Germany, plus I have the old ABS control unit. Car has brand new drilled rotors and new pads all around. Master cylinder and reservoir/expansion tank and cap are no where to be found. That is all I need to get this baby drivable again. Before I lay down $525 for just the master cylinder ( on ebay with no expansion tank or cap) I want to see if anyone has a deal on a good used one with the reservoir and cap. Also I am wondering what the real difference is on the master cylinder from the 750il or 840ci besides parts numbers? When I look up the master cylinder for a 91-93ish 750il sedan I obviously get a different part number but the master cylinder picture looks identical to the 850i one. I know sometimes on the internet they use just a stock photo of a master cylinder but I really wonder how different the bore and travel really are on these master cylinders. I have a buddy whom works at a local Oreilly's and the site shows that they carry the master cylinder but he is having to email his corporate office because his store computer does not let him order it. Way better priced at oreilly's , $99.94 with a 1.062 bore, 750il sedan part shows 1.0 bore a .062 difference. I'm guessing German Engineers made it a slightly different bore for a reason right? I know some parts for these beasts are expensive and I have no problem with that just trying to see if I could save a few dollars before I go the "new " route and I would have never guessed that the brake master cylinder for this car was this unique. Contacting this lady's husband and asking where he left this part is not an option, lets say he is "legally troubled", ... for a long, long time. I am going to contact a a local bmw specialist who did work on this car before I got it. ( I found an invoice from this shop in all the paper work and service records I received with the car.) Any and all info welcomed. I did just also contact a fellow bimmerforum member who is parting out an e31. Waiting to see his response. All I want to do is drive this beautiful car! With thanks.
Anovaso

[ross1]

That is a pricey little devil and doesn't interchange with other cars from what I can tell.
Check in with these guys, they ought to have a good alternative;http://www.bimmerforums.com/forum/fo...8-Series-(E31)
A master cylinder isn't difficult to re-build if you can find the correct seals, hopefully the brain trust in the 8 forum will help.
Nice car, good luck

[anovaso]

Thanks ross1 , yes the car is beautiful, thank you. Looks like the car was featured on another post last month, another guy went to look at it before I did and hesitated to buy it but I ended up with it after just seeing it once! Car looks amazing just standing still! But still it's time to get it back together and drive it.
I am not a newbie by any means to wrenching and have worked on still work on all my bmws, e24, e30, e21, e23, e34 and now my e31 is a whole new but beautiful beast.
This is where I am at now and I need some help or direction as there is a lot of different information on this forum about these early e31's.
1. I have the replacement used ABS hydraulic unit and the old unit that came with the car, both out of the car. Do I use Pentosin 7.1 or Pentosin 11s to refill this system and install new used ABS hydraulic unit, where do I fill and bleed this system from and is there a certain process or anything else to look for when doing this? The reason I mention different Pentonsin versions is that when I look up info on this abs system, some say that both power steering and ABS use pentosin but do they share the fluids? Online the power steering shows it uses pentosin 11s? Or are these two system separate from each other,and the brake power booster and abs connected?

2. I just ordered the Brake master cylinder from Oreilly's, my buddy's friend is a manager at a local oreilly's and is ordering the master cylinder shown on their
system and at an awesome price of $94.99. Do I just use regular but good quality Brake fluid? I do have some Prestone Synthetic Brake fluid, is that ok?
Clutch master cylinder is untouched and clutch seems to work fine when i start the car and go through the gears. I am ordering the used brake fluid reservoir/expansion tank and cap from another used part source online as i write this.

3. My car shows it has ASC and DSC and is a 6 speed, so some forum post and info on the internet say that the 6 speeds indeed have ASC +T for traction control. How do i know for sure that it does or not? And the biggest questions about the ASC and DSC, info I find on these systems say they are electronically controlled systems. So does that mean they do not have any direct hydraulic relationship to my abs or power steering Pentosin systems? Or are they electronically controlled hydraulic systems?
There is just so much info out there and I want to be sure I have everything correct when putting everything back together.I am not penny pinching at this point. This car deserves to be put back together correctly and I am going to that and I know this car cost money to maintain correctly as well, not a problem.
Thanks for any info or direction. Tony