Early Master Cylinder

[Mike Heagney]

Hi all,
The master cylinder removed from my 64 230 SL was a version 3, and should be a version 1.
Version 1 has the first(push rod)piston operating front disc brakes,with second piston(floating)operating rear drums.All subsequent 2,3and 4th versions operated reverse to this.Also each version has check valves to regulate residual brake line pressure to disc or drums,or all discs.
A replacement version 1 is NLA so I'm told.The new part is 001 430 6304 which  apparently covers several versions.So I'm confused.
How can the new master cylinder operate two systems which are opposite each other.
Has anyone with an early 230 fitted a new 001 430 6304 with no detrimental results, or is there more and better information out there.Thanks guys.
Mike
64 230 SL in bits.

[Naj ✝︎]

http://pagoda113.com/eve/ubb.x/a/tpc/f/2076001521/m/918100513/r/918100513#918100513

[twistedtree]

I realize this is a very old thread, but I'm now facing the same problem.  My '64 230 has what I gather is called the version I master cylinder where the front part operates the rear brakes, and the rear part operates the front brakes.  It also has only two line attachments ports on the cylinder, and an external Tee fitting branches out to the left and right front brakes.  On the later version, the front section of the cylinder operates the front brakes, and the rear part operates the rear brakes - that's just the opposite of the earlier version.  Also, the newer one has three ports on the cylinder, with the front left and right lines each attaching directly to the cylinder eliminating the external Tee on the older model.

If I update to the new version, it looks like I will have to also re-do all my brake lines where they come to the master cylinder.

Is there some better trick to this?

[jacovdw]

Unfortunately the older versions of the master cylinders are NLA and that includes their associated rebuild kits.
The later version is considered an accepted upgrade.

There is a way around this and I have done so on my 230SL and requires a small modification to the brake lines (no major surgery required).
The line for the rear brake circuit can be moved and fitted to the rear port of the master cylinder.

On my car, I retained the chassis mounted tee fitting and fitted the short line to the top port of the front of the master cylinder.
Fortunately, the bottom port is not so visible and there is a screw plug and a seal ring that can be fitted (mentioned in the service manual) to plug the bottom front port.

Unfortunately I did not take any photos to illustrate the process.

[twistedtree]

That's exactly what I was envisioning.  That's for confirming.  Now I just need to find a plug.....