tii booster swap

bimmerboy73

bimmerboy73

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Greetings all...

wanted to know if anyone could give a new guy some advice on what all is involved in swapping out the e9 brake booster for the tii. I'm in the process of completing a triple weber swap and have come to the conclusion that i'd rather free up the engine bay and provide some extra space for the weber's than try to shoe horn them in. Its EXTREMELY tight ... even had to shave down the studs to get the 2nd one in. With everything buttoned i probably have maybe 2" clear between the carb and the booster.

Questions...

Is there a specific year that works or is it all tii's?

what in addition to the booster will i need to pick up?

will the e9 MC work or do i need that from the tii as well.

ANd finally... is this a reasonable DIY? I'm hoping it is as i'm 90% through the weber install and would like to go ahead and knock this out if possible.

Thanks in advance.

Richard
 
I've never done the swap in an e9, but have in 2002s and it is rasonably the same, if I understand correctly.

First, all tii brake boosters are the same.

The hardest parts of the conversion are (1) putting back on the pesky circlip that connects the booster to the rod coming (indirectly) form the pedal and (2) bending the brake lines to fit on the tii booster. The tii booster is longer and narrower, so the lines need to be forward by a few inches. On 2002s, usually, but not always, there is enough extra line, that you can bend them forward a few inches to achieve this. But, sometimes there isn't and you need a new line. Can't speak to the e9 on this.

The brake master should fit on the tii booster fine (all BMW masters of that vintage are about the same -- at least length wise).

You shouldn't need anything other than the booster -- unless the brake lines are not long enough....

Good luck.
 
Yep, the lines were a pain. Don't forget the O-ring that goes between the cylinder and the booster, otherwise you will have a nastly brake fluid leak exactly where you can't easily get to it.
 
Yes

It's reasonable for a person of moderate mechanical ability to do this.

You really want flare nut wrenches for those brake lines, they make it a LOT less likely to strip the nuts. A set is not expensive, in coupe terms, though you will get very limited use from them. If you could find individual flare nut wrenches this is one time where the price of one or two wrenches might be preferable to buying a set.

You didn't mention the other possibility, to fit the hydraulic brake booster system. And since you didn't mention it I won't go into it. BUT, if you don't have a tii booster (and I don't know what they are going for used) you might be better in some way with the hydraulic booster. More parts, but they can be made to fit, and could be more obtainable than the tii booster which came on only one model produced for only on 72, 73, 74 years for USA.
 
Re: Yes

Honolulu said:
You really want flare nut wrenches for those brake lines, they make it a LOT less likely to strip the nuts.
Click to expand...

Oh, yeah. He's right on that one. Had one so long I forgot. In fact, I dare say don't try it without one.
 
And before you use your flare wrench, spray every pipe connection with a good penetrating fluid, like Kroil or PB Blaster (not WD40).

Regarding tii boosters; I hate to admit this, but 2000CSs use the same booster as do 2002tii s.

Some trivia: If you are outside the US, the twin carb 1600ti/2002ti also used the same booster. By my count, there were about 70,000 BMWs sold world-wide that used the booster.

Unfortunately, I think only about 10,000 were sold in the US. Still, they aren't exactly rare.
 
Urgent help needed-

Thanks for all of the input. Picked up the recommended supplies and got going on the swap this afternoon. Brake lines came free without a problem. Even managed to get by with only removing 3 of the 4. The MC and booster are free save for the rod that connects the booster to the brake pedal. What's the trick to freeing up the rod and getting to the circlip? I already disconnected the pedal in the cabin but cant seem to figure out the rest.

Also - anyone have any experience using synthetic brake fluid (DOT3). Picked some up this afternoon but figured i'd ask before i used it.

Richard
 
more problems

so. got the booster out this morning (not going to say why i was having problems... a little too embarrassing). but now i have a new dilemma. the tii booster i purchased has a stem (opposite side of the MC) that is much shooter than the stem that connected to the brake pedal on the 3.0 booster. I'm assuming there's some sort of modification that needs to be done to extend the stem / rod far enough to reach the pedal? In desperate need of help here. And please forgive the newby ignorance...

Any assistance would be greatly appreciated.

Thanks!
 
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