Results 1 to 7 of 7

Thread: What's the real deal with E32 master cylinders?

  1. #1
    Join Date
    Mar 2012
    Location
    Hopewell Junction, NY
    Posts
    2,639
    My Cars
    1987 325iS...edan

    What's the real deal with E32 master cylinders?

    Alright.


    I've read various things about this and can't come to any clear understanding whether or not doing this is worth it.

    4/87 325i.

    I have a stock braking system and a spongy pedal.


    I've bled everything more than once, and I've changed soft hose, pads, etc.


    Solid rotors, ATE pads.


    Pedal does not sink with the car on or off, though it does get stiffer after one pump in both situations.


    I'm aware the 25mm cylinder is not internally biased, and will increase rear bias. I'm not aware if that makes any real difference under normal street driving.


    I have ABS, so I'm not worried about the number of ports. I believe the pipes/hoses on the car will pop right in, but please let me know if that's not the case.


    My goal would be to get rid of some of the sponginess and pedal travel. It would make heel-toe a little nicer and would increase my comfort using the brakes a bit.


    1) Does this make a noticeable difference re: pedal travel and feel?
    2) Is the increase in pedal pressure annoying for regular driving?
    3) Anything else I'm not aware of?


    Thanks!
    Last edited by ELVA164; 04-19-2018 at 11:47 AM.
    Interested in vintage cars? Ever thought about racing one?
    Info, photos, videos, and more can be found at www.michaelsvintageracing.com!


    Elva Courier build thread here!

  2. #2
    Join Date
    Mar 2012
    Location
    Hopewell Junction, NY
    Posts
    2,639
    My Cars
    1987 325iS...edan
    Brake master cylinder update:

    The master cylinder size in my car is 20.64mm front and rear with an external proportioning valve. A late-model cylinder is
    22.20/17.64mm, obviously internally proportioned.
    If I go to a late-model cylinder, I'll move the bias more to the rear.

    If I go to an E32 cylinder the bias stays correct but the change in size is considerable. I'm wondering if it would be too much.

    Do I:

    A) Use a late-model cylinder; or

    B) Use the E32 cylinder?
    Last edited by ELVA164; 04-22-2018 at 11:53 PM.
    Interested in vintage cars? Ever thought about racing one?
    Info, photos, videos, and more can be found at www.michaelsvintageracing.com!


    Elva Courier build thread here!

  3. #3
    Join Date
    Mar 2012
    Location
    Hopewell Junction, NY
    Posts
    2,639
    My Cars
    1987 325iS...edan
    Any thoughts?
    Interested in vintage cars? Ever thought about racing one?
    Info, photos, videos, and more can be found at www.michaelsvintageracing.com!


    Elva Courier build thread here!

  4. #4
    Join Date
    Nov 2009
    Location
    Realville
    Posts
    1,216
    My Cars
    93 525iT,91 318i
    If I remember basic hydraulics correctly, a 25mm master will require 46% more pedal force than 20.6mm? Don't know how much of that would be moderated by the booster, so you might also consider the need to replace your booster with a larger unit as well.

  5. #5
    Join Date
    Mar 2012
    Location
    Hopewell Junction, NY
    Posts
    2,639
    My Cars
    1987 325iS...edan
    Quote Originally Posted by locknload View Post
    If I remember basic hydraulics correctly, a 25mm master will require 46% more pedal force than 20.6mm? Don't know how much of that would be moderated by the booster, so you might also consider the need to replace your booster with a larger unit as well.
    It appears to me a swap with a later E30 master may be the way to go. I was hoping for some experiences, but maybe this particular job isn't done very often.
    Interested in vintage cars? Ever thought about racing one?
    Info, photos, videos, and more can be found at www.michaelsvintageracing.com!


    Elva Courier build thread here!

  6. #6
    Join Date
    Mar 2012
    Location
    Hopewell Junction, NY
    Posts
    2,639
    My Cars
    1987 325iS...edan
    UPDATE


    I got the late stock E30 master installed and the pedal feels much better. If you have a pre- 5/87 build date car and don't like your pedal, but you're keeping stock brakes, just use the late stock master.
    Interested in vintage cars? Ever thought about racing one?
    Info, photos, videos, and more can be found at www.michaelsvintageracing.com!


    Elva Courier build thread here!

  7. #7
    Join Date
    Dec 2005
    Location
    corpus christi, texas
    Posts
    6,738
    My Cars
    No e30s, again :(
    good to know.
    No e30s again.

Similar Threads

  1. What is the real deal on running E36 M3 springs on an E30?
    By phenryiv1 in forum 1983 - 1991 (E30)
    Replies: 33
    Last Post: 09-17-2009, 03:10 PM
  2. What is the big deal with driving in snow?
    By Quailane in forum 1991 - 1999 (E36)
    Replies: 42
    Last Post: 12-21-2007, 12:10 AM
  3. The Real Deal With Water Pump???
    By sloppyjoe86 in forum 1991 - 1999 (E36)
    Replies: 7
    Last Post: 09-23-2007, 09:26 PM
  4. What's the Real deal with SHARK Injector?
    By bimmersinner in forum 1992 - 1999 M3 (E36)
    Replies: 13
    Last Post: 10-02-2006, 08:16 PM
  5. So what's the install deal with Rieger body kits?
    By BS05ZHP in forum BMW Rides & Events
    Replies: 63
    Last Post: 02-22-2004, 09:03 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •