brakes Tii Booster Swap - New Brake Lines Or Massage?

[bruno615]

Gents,

 

Having recently installed a motor with dual Weber DCOE 45 sidedrafts, I am having a clearance issue on cylinder 3.  There's only about 1-2mm when resting, but they collide under starting and acceleration in reverse.  It seems I'm stuck at a point of needing angled airhorns or changing the booster (or both =).  With spring approaching quickly, I'm setting up a game plan.

 

I realize that I'm not the only guy to have these issues.  My question is, how hard is it to do the Booster Swap?  (I figure I will also install the Tii Master Cylinder at the same time).  How does the difficulty compare of massaging the existing fittings with bending all new lines?  I'd prefer to do what's easier, unless it will look horrible.

 

Mike

 

Bonus Question:  Is there any way I can test a Booster/MC before installing one?

 

 

[nbcbird]

FWIW, the tii booster/master cylinder repositions the brake lines about 30mm forward (compared to the non-tii version).

[tjones02]

The Tii booster can be installed without changing the brake pipes. We do it both ways depending on the owner's request and if the car is expected to win trophies.

 

If your brake pipes don't look too rusty (if they look like they'll bend without breaking then go ahead and do it with the existing pipes.

 

If when bending them one gets kinked in any way, you need to replace the pipe.

 

The pipes can be bent/stretched by hand.

 

Leave the M/C loose on the studs until you have ALL the fittings threaded in. They don't have to be in all the way, but far enough that you're sure they're not cross threaded. If the fittings can't be threaded in by hand the pipes aren't bent into the right place yet, align them better before you cross any threads.

 

Keep in mind that you're a DIYer and you have more time to get things just right...

 

Be ready with a length of proper brake booster hose to route it to the very different location of the Tii booster. It's also a good time to replace the hoses from the brake reservoir; proper brake fluid hose is advised. Sometimes the reservoir and the nipples st the M/C break when changing the hoses. I use brake fluid to lube the fittings and hose rather than any other type of lube.

 

While I'm at it and looking at that picture of your engine bay...

 

Please install a correct sized Group 47 battery with a correct '02 or 320i hold down (BMW superseded the hold down to one that does not work).

 

That positive cable is mightily close to the alternator fan and I'd hate to hear of it being shredded. The original '02 battery hold down helps to keep the positive wire away from the alternator; the wire tucks in between the holder rod and battery. The battery that's in there now could tip over and push the positive cable into that alternator fan...

 

Those additional red power wires are best routed along the body wire harness, away from the negative battery terminal.

 

Bonus answer: it's easier to test a brake booster in the car than out.

 

Cheers and HTH,

Edited February 21, 2014 by tjones02

[M3M3M3]

excellent summary by Tom!

 

only option i would add is to ditch the big wet acid battery and put a much smaller AGM battery under the back seat instead.

[bnam]

The BMW parts list shows a cable clip that's attached to the alternator (#18) -- is that originally for the positive cable?

Anyone repro that part?

 

[tjones02]

As far as I recall that clip is for early cars (68-69) where the alternator harness comes from the radiator support, not for the positive battery cable.

[Kidasters]

 

Tom has answered your questions.  When I did the Tii booster swap, I couldn't get the lines to work right.

 

The one that gave me a problem was one of the lines to the left front wheel.  No matter how I bent it, I couldn't get it to fit.  I measured and bought a slightly longer one from Blunt - hand bent it and in place.

 

Other than that - the only other tough part is the clip you need to hold the pin between the booster and the pedal.  Do a search, but instead of the stock clip there is a clip from an E21 that works better.

 

hope that helps.

 

Ken

Edited February 21, 2014 by Kidasters

[DUDONLY]

Or what wasn't mentioned is: IE makes an intake for your carbs that will give you the needed room for the horns without changing the brake booster.

[eurotrash]

^  That's totally where my mind was going.  the Alpina, Korman, IE manifolds all are shorter.  And waaaaay easier to swap to.

 

Here is my IE manifold with Dellortos.  I have 3/4" air horns under the air cleaners.

 

 

Edited February 21, 2014 by eurotrash

[bruno615]

Thanks for the detailed reply Tom!

 

The motor was done to Korman's stage 3 level, I believe it has the Korman manifold.  Could be wrong though.  Given the headache of redoing the linkage and retuning the carbs, and the fact that I have bigger brakes, I'm going to go the Tii Booster route.  Sure, I'd love to find a set of angled 45 stacks (Paging AceAndrew), but they're pretty rare.

 

Battery is currently unsecured and wires are a mess because I'm in the process of rewrapping the harness   Besides, I forgot and left the battery outside all winter, so chances are it's toast...  I'm currently deciding between under the seat and in the rear TEP strut brace.  Not looking forward to routing the wire though.  (And what do people do for a battery terminal, seems there's only 1 guy that's mentioned the issue?)

[eurotrash]

Booster won't help the braking, only Tii/5series master cyl. will.  FWIW, I have volvo fronts and rear disk, on a carb'd 2002 master cylinder.  I added an adjustable proportioning valve for the rear and gutted the one on the master..

 

I went the route of the TEP rear kit, because it came with the car, uninstalled.  I got a block from a 90's 5 series (IIRC) and hung it up front so I could bolt on the harness without molesting the wires.

 

Edited February 21, 2014 by eurotrash

[bruno615]

Oh yeah, I'm going to do the Tii MC too.  What do I need to mod on the MC to install a proportioning valve?

 

That Terminal Block looks better than most, but I want something a bit more covered.  I've still got some more research to do.

 

Booster won't help the braking, only Tii/5series master cyl. will.  FWIW, I have volvo fronts and rear disk, on a carb'd 2002 master cylinder.  I added an adjustable proportioning valve for the rear and gutted the one on the master..

 

I went the route of the TEP rear kit, because it came with the car, uninstalled.  I got a block from a 90's 5 series (IIRC) and hung it up front so I could bolt on the harness without molesting the wires.

 

 

[Scattergun4015]

 

 

The motor was done to Korman's stage 3 level, I believe it has the Korman manifold.

 

If it is a Korman intake manifold it should have Korman cast into the manifold between cylinder's 2 and 3

Edited February 22, 2014 by Scattergun4015

[tjones02]

Here's one option. Usually I mount the valve on the fender-well with rubber bushings, but this one had the convenient remnants of battery tray. That IS the rear brake pipe that you need though. A brake pipe double bubble flare tool and bender is required though. Many think that they're gonna' be adjusting the brake bias all the time, but reality is that you usually set it and forget it. Maybe, just maybe for autocrossing one might want to dial in more rear bias to get the car to rotate, but that's about the only situation that I can think of where you'd wanna' change it from the "street" setting. I can easily take another pic if needed.

 

You want the fronts to lock JUST before the rears. It's up to you where you test them to set it up. We usually set it for the customer and tell them to never touch it.

 

When I was younger, in my own car I imagined plumbing the pipes up through the shifter hole and mounting the valve under the driver seat near the trans tunnel so I could reach it while driving... In reality it just doesn't need to be reachable from the cockpit unless it really is a race car.

[jgerock]

As far as I recall that clip is for early cars (68-69) where the alternator harness comes from the radiator support, not for the positive battery cable.

Picture of my 69 engine with the securing clip