View Full Version : Help with removing the Master Cylinder

11-16-2008, 08:31 AM
Hello Everyone,

My clutch pedal recently went straight to the floor. After troubleshooting, I noticed it was leaking around the slave cylinder. I have replaced the slave cylinder, and I wanted to go ahead and change the master cylinder.

E34, 525I, 1990,

I have run into a problem!:dunno: I was able to remove the two bolts and the eccentric screw, very easiley (should have been my first clue), however, I am not able to losen the line that terminates in the back of the master cylinder.:mad:

It is the same line which ultimately feeds into the slave cylinder.

Can anyone please provide any tips/suggestions/recommendation on how to disconnect the master cylinder from this bolt? I have tried flare nut wrench, WD-40, regular open wrench. As anyone who might have done this job knows, it is very tight under the dash. You are working blindley.
It has gotten so bad now, I am questioning the orientation removal; meaning if you are facing the line, do you turn the wrench counter clock-wise to clockwise.

Thanks in advance for any help you can provide.

attack eagle
11-16-2008, 04:00 PM
you have two choices. undo it from the engine bay, or unmount the master and Bend the line enough to access it from inside the car.

I spent 8 hours trying to get that line on when I converted to 5 speed. Good luck. keep at it.

11-16-2008, 06:08 PM
I was affraid of that. :cry:
This is not going to be fun. It's cold outside, and I can't move the car to the garage to work on it.

I appreciate the suggestion. I guess I will try that next weekend. What kind of tool did you use if you don't mind telling me?


11-16-2008, 07:10 PM
There is an access hole in the inner fender, it's covered by a rectangular plug.

attack eagle
11-16-2008, 07:45 PM
cool I didn't see that when i did mine.

I used an open end wrench m62b.

11-22-2008, 04:28 PM
Well, the weather was nice today, so I decided to go ahead and see if there is an access door in the inner fender. I didn't see it. You can see where the brake line is going to the front brakes, but there was no door.

To make things even worse, as I attempted to once again to remove the bolt from the master cylinder, I guess moving the line caused it to get weak, and end up breaking it off (not by choice). :mad: :mad: :mad:

So, now I have to figure out how to run a new line to the master cycliner.

Anyone out there by any chance replaced the line going to the master cylinder?

Thanks for all that have replied.

attack eagle
11-24-2008, 01:31 AM
yes I did since mine didn't have one to begin with.

my suggestion if you can find a shop that builds hoses, have them make you up a new softline from the master to the rear hard line.

Otherwise a VW brakeline supposedly works an cna be easily bent after the line is attached to the master.

11-24-2008, 08:54 PM
As much as I like working on my vehicles, I think I may have to have this one done professionaly.

I guess I will have it towed to my Mech. and see what he can do.

I will look into to the VW line. Hopefully I can find it.


11-30-2008, 06:42 AM
I too am struggling with the replacement of the master cylinder outside in November. I disconnected the hardline which at the flexible line coupling which is affixed to the underside of the car. Difficult but not a huge problem. Unbolting the master cylinder was made difficult by the fact that wiring which is twenty years old is not very flexible anymore and it is definitely in the way, but I got it loose and was able to disconnect the pedal linkage. Then came the difficult part. Pulling the master out of the firewall from under the console. What I finally figured out was the stop, when I yanked so hard it came out, was the fluid feeder line, which I had not pulled out of the MC body. The hardline came through the firewall just fine, without being bent, which alleviated the issue of how to get to the MC/hardline junction while it was in place, which is visible from the underside of the car, but virtually impossible to get to with a wrench and any leverage while laying on your back.

My remaining problem, besides the fact that one of the MC mounting bolts fell down behind something (Carpet maybe) and I will now have to get a replacement, is how do you get the feeder line back into the Master Cylinder? I realize it's a pressure fitting, meaning you are supposed to shove the sucker in to the body, but how, praytell, do you do that? Do you do it when it's installed? I see no way to get a hand or pliers, or anything over this to deliver enough force to put it back into the MC body?

Help and suggestions appreciated.

12-01-2008, 07:13 AM

this little part seems to be the device to solve my problems. Would have been nice to know that it could be installed on the master cylinder prior to installing it. The fact that I lost one of the two screws does mean removal will be a bit easier...