Brake master cylinder confusion...

[Ryan Stewart]

OK, the new MC has only two outlets but currently I have three. It seems one power the rear and then the fronts are independent. Now I looked at a buddies 325ix and it looks like he has only two. Did they change the front system later? Is it just a check valve system?

[AdamF 88iS]

You don't have ABS. The front channel splits after the ABS unit on cars so equipped.

[Ryan Stewart]

crap, so I guess that means I cant use an uprated mater cylinder with the dual chamber booster?

I wonder if there is a way to split mine with a check valve like the rear?

[AdamF 88iS]

I wonder if there is a way to split mine with a check valve like the rear?

I suppose you could, but I have no idea what that would do to the front/rear bias.

[Ryan Stewart]

well the way my system appears there is a port on the back of the MC for the rear and those go back to a bias controller and then on the front where you have one port there is another just below it. There cant be anything inside there that would do anythign special I can see, it just looks like there are two spots for fluid to run.

I would just replace those two ports with one and run a d-block to the fronts and the rear would stay on that back port. I guess if I am stuck I could just use the 325i MC with the 320i booster but I would much rather be running the larger MC.

[kco325]

I've recently been looking at this (25mm MC on an eta) and I've found that the rear bias (if it exists) is somewhere else in the car, whereas the front one is quite visible in the engine bay, under the MC. I don't see why you can't put in the 25mm and just run the single line into your old front bias. Mind you, you'll have to modify some brake lines, but that's a piece of cake. Just be careful not to crush any lines.

[E30-323ti]

I had the same issue on my 323i (no ABS).

I just got a Tee piece & 150mm of brakeline (with flared ends and fittings).
Put the Tee between the two stock lines (to the front brakes) and the new line goes from the Tee to the MC, piece of cake.

The brakeline and Tee are avaliable from any brake shop.

[trent]

I had the same issue on my 323i (no ABS).

I just got a Tee piece & 150mm of brakeline (with flared ends and fittings).
Put the Tee between the two stock lines (to the front brakes) and the new line goes from the Tee to the MC, piece of cake.

The brakeline and Tee are avaliable from any brake shop.

Ryan,

This is correct. Just split the signal.

[Ryan Stewart]

Thanks guys. This means I can run the larger MC. :up:

Will do next weekend>