master cylinder and booster interchangability

[tjmonsen5]

My buddies has an 85 325e. HIs master was leaking into his booster. The brakes had basically failed. So, i found him a good master cylinder and booster from a 318is because I thought all masters and boosters were interchangeable. He gave the car and the 318is brake setup to his mechanic, and the mechanic said the setup wont fit, or wont work. I dont know why.

I thought these were supposed to work on any E30???

I was told that the mechanic ordered a new master and booster from a local parts store for a total of around 200 bucks, i guess thats a good price.

[Massive Lee]

He gave the car and the 318is brake setup to his mechanic, and the mechanic said the setup wont fit, or wont work. I dont know why.

We don't know either. You need to tell us a few more details as why the wrencher says it doesn't fit.

[tjmonsen5]

Im just relaying information that I heard from my buddy. He lives about 200 miles away from me, so im just trying to give you guys everything I know.

So you are saying that it should fit?

[Massive Lee]

If the parts are what you say they are, then they should mechanically fit.

Then again, we have too little info to be of any help. The mechanic should tell why it doesn't fit, and why it doesn't work. A scrap part from a scrap yard is just that. Scrap. Perhaps the parts you took were also in non-working condition...

[tjmonsen5]

nope, they came from my other friends running 318is, because he did an S50 swap and used a 735 booster/master. The part works just fine.

I called the mechanic and left a message, we will see if he calls me back.

[FredK]

Did early model MCs have 3 ports?

[tjmonsen5]

Just got a call back from the mechanic.

The master cylinder on my buddies 325e has 3 fittings, the 318is master has 2.
The diameter of master where it goes into the booster is over an inch bigger.

Could be because the 318is had abs, and the 325e does not.

[Massive Lee]

The early 325e had optional ABS.

[Uliv1c]

Must be a girling brake system/ or Ate....

[6gen91]

Where in illinois are you?

[tjmonsen5]

crystal lake