Power brake booster

kittman · Post by **kittman** » Mon Feb 11, 2002 7:43 am

Were most 411/412's sold with power brakes? My 412 doesn't have power brakes. Does anyone know if the booster can be added to a car that doesn't have power brakes? I've been spoiled by the power brakes on my bus, and I'm hoping that I can add the booster (if I can find one) to my 412.

Can anyone share some insight on this?

Thanks!
Jeff
73 412 Sedan

adam412 · Post by **adam412** » Mon Feb 11, 2002 12:28 pm

I don't know about power brakes... but a trick that works on the notoriously mushy Type 4 brakes is to pull up the emergency brake three notches on the ratchet. Not too far, but enough to increase braking power significantly.

It worked for me: I thought I needed to replace my brakes when I bought my '74 412 wagon, but that little trick made my brakes feel fine. Hope it helps you.

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Il y a des fleurs partout pour eux qui veulent bien les voirs. - Henri Matisse

kittman · Post by **kittman** » Mon Feb 11, 2002 1:30 pm

Cool, thanks for the tip! I've noticed that the brakes are much more firm after the parking brake has been engaged. Do you have any problems with the brakes dragging?

Thanks,
Jeff

LM · Post by LM » Mon Feb 11, 2002 7:39 pm

My Dad had a 412 years ago, and I clearly remember that rear brake adjustment, (at the wheels), was a regular feature of life if the brakes were to perform well. Self-adjusting brakes were available as an option. It might be worth seeking these bits first as it has to be easier than fitting the servo components.

Good luck.

adam412 · Post by **adam412** » Mon Feb 11, 2002 10:15 pm

No, I haven't had any problems with dragging, the brakes work and disengage just fine... I just drove north of San Francisco to Bolinas, on the extremely twisty and hilly Route 1, and my brakes did great down the hills, and the car did fine going up.

I don't think the emergency brake trick has any serious repercussions, but I defer to anyone more knowledgeable on the topic..

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Il y a des fleurs partout pour eux qui veulent bien les voirs. - Henri Matisse

Chris Percival · Post by **Chris Percival** » Tue Feb 12, 2002 7:48 am

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by adam412:
I don't know about power brakes... but a trick that works on the notoriously mushy Type 4 brakes is to pull up the emergency brake three notches on the ratchet. Not too far, but enough to increase braking power significantly.<HR></BLOCKQUOTE>

Isn't that just to take up slack in the rears which should have been adjusted up anyway?

ray greenwood · Post by **ray greenwood** » Tue Feb 12, 2002 8:02 am

Brake adjustment on a regularly driven 411/412 is a once a month thing...believe me...or pedal travel will get excessive. What also really helps, is teflon stainless braided brake lines. They are also cheaper now than stock brake lines. I believe from what I remember, that the rear brake lines from one of the last years of swingaxle bug are the part #'s to use that will get you stainless part #'s. Just pull the part # off of your stock brake line and take it in for matchup. The same brake line fits all four corners. I have never seen the power brake option on this continent in person. It is essentially the same master-cylinder and power unit as the bus. If you look in your car, the indention is there in the sheet metal for where the hole is made at the factory, to install the booster, which goes in the trunk. What will be hard...if not impossible to find...are the pivot, pivot bracket and rod that activates the cylinder. They are similar in appearance to what is install in Vanagon...but not quite the same pivot ration. With front ventilated rotors, high quality pads...and mintex rear shoes (soon to be discs) and braided brake lines...I have found no reason to pursue power brakes anymore. My 412 stops on a dime. By the way,I have found that when working on the type 4's, that you will need to bleed the brakes at least twice, in about a 4 day period with driving in between to properly get all of the air our. This even happens with power bleeding. There are too many concolutions to the tubing. At the sharper, higher bends, the tubing is just large enough in diameter to allow slow moving fluid to pass air bubbles caught in high spots. Ray

nick sparrow · Post by **nick sparrow** » Tue Feb 12, 2002 4:50 pm

Hello there Ray ,
You said that you have vented front rotors, and about to fit up discs to the rear, what rotors and callipers are you using?.... as I was just about to start looking into upgrading the brakes on my 74’ 412LS ...any help would be wonderful.

nick sparrow

ray greenwood · Post by **ray greenwood** » Thu Feb 14, 2002 7:12 pm

Vented is probably not the correct word. They are cross drilled and chamfered. That made a heck of a difference. The rear stubs on a type 4, though having a really different bearing configuration than the type 3, use the same rear hubs. With just a little bit of shaving...very little....around the outside rim of the 411/412 stub, you can use the CB performance rear disc brake system. It uses 914 rear rotors, a GM caliper (or you can buy the cast brakets seperate and use something else...for about $100 ). The front calipers form some of the Audi 4000/5000 and VW quantum will bolt up nicely and have e-brake hook-up. The rear bearing cover is essentially the same as the type 1 on the 412. You might have to take about .020 off of the caliper brackets from CB, as the backing plate on the 411/412 is thinner...but thats easy. I will probably buy 914 rotors here locally...cause I can get them reasonably, cross drill them, use a pair of rebuilt Audi calipers I already own, and have the stub turned a little. I will get away for about $250 bucks. Ray