General Type 4 Question: Power Assist Brakes

ClassicCamper · Samba Member Joined: December 17, 2002 Posts: 679

I was combing around the forum and found some references to power/power assist brakes. Was this ever offered as an option (or standard equipment for all I know) any of the T4's in the US?

raygreenwood · Posted: Sun Jun 07, 2015 8:42 am Post subject:

It was an option from the factory.....and I have never seen one in my lifetime....and I have seen more type 4s than most.

Its most probably due to the fact that outside of using a wagkn/variant fully loaded all the time say...like for business.....its pretty much not necessary. The brakes worked very well on these cars with little effort.

The only optikopoptions that really make sense are self adjusting rear drums....also an option....but I have never seen it here either.

As I start to finish out the brakes in the fall on mine....I will be installing a 21mm bus MC....in the trunk. To do this, I will be drilling out the stamping in the trunk where the power assist MC was designed to go through. The stamping is there in all type 4 cars.

It means adding a steel flange for the MC to bolt to that will bolt into the firewall. But thats pretty easy. It will also mean making the fulcrum pivot from scratch that the factory added. You can see all of the power brake unit parts and locations in the Haynes manual.

This will also mean that I will have to install a brake biasing adjuster valve as the brake bias is different from master cylinder to master cylindef from different vehicles. Since I will be replacing the factory stock rear brake pressure regulator with something more easily, adjustable and replaceable (rear brake bias and rear pressure limiting are not the same thing).....it wont be a big deal. I am also installing rear discs.

The larger volume master cylinder along with stainless teflon hoses should give quite a bit more pressure faster. Ray

Lars S · Posted: Sun Jun 07, 2015 10:03 pm Post subject:

In my country most (maybe all) Typ4's were equipped with both power brakes and self adjusting rear brakes as soon as it was available from factory (-72?).

My feel is that the brakes today feels more effective (nearly as any modern car) than back in the times, maybe because of softer pad and shoe material.

I had to skip the self adjusting thing since the shoes for it are not available anymore Sad

/Lars S
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raygreenwood · Posted: Mon Jun 08, 2015 6:32 am Post subject:

vonkr · Posted: Wed Jun 10, 2015 10:39 pm Post subject:

I had one, many years ago. Sold it to a scandinavian guy.

http://www.keversite.nl/fotoalbum/fotos/103346.jpg

hulken · Posted: Thu Jun 11, 2015 3:34 pm Post subject:

vonkr · Posted: Sat Jun 27, 2015 12:07 am Post subject:

Kharon8 · Posted: Mon Jun 29, 2015 12:17 pm Post subject:

And here's one in the car:
http://kharon.suomiforum.com/www/412/IMG_3507.jpg

Originally Swedish car, explains the booster.

I was browsing through the parts pile in Sunday and found the cover plate for the booster too, nice. Not installed yet but I have one.
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Kharon -- '62 typ1, '63 typ14, '61 typ21, '65 typ34, '74 412, '75 typ26
FVWA.fi support group.

titan3c · Posted: Fri Jul 03, 2015 4:41 am Post subject:

titan3c · Posted: Fri Jul 03, 2015 4:46 am Post subject:

Please let me know when you decide what pressure regulator, or proportionate valve you use. What are some of the problems with a faulty pressure regulator? Bob

raygreenwood · Posted: Fri Jul 03, 2015 5:33 am Post subject:

I will look around this weekend and see what may work. The things go remember is that the type 4 regulator has one inlet and two outlets. You could do it that way or even get one that has a single inlet and outlet and go to a "T".

The factory setting starting limiting brake pressure at 525 lbs. Ray

hulken · Posted: Sat Jul 04, 2015 1:42 am Post subject:

titan3c · Posted: Sat Jul 04, 2015 4:08 am Post subject: pressure regulator

Thanks Ray, I'll wait and see which one you decide to use. I didn't know there was so many different models of these, and that I could use them on a 411.

raygreenwood · Posted: Sat Jul 04, 2015 5:53 am Post subject:

Pretty much brakes are brakes and pressure is pressure. You need to find one that has infinite adjustment by a screw....and not one that just goes in notches. Also.....preferable to find one close to the same size...maybe even close to same port spacing.....and be sure you are looking at a brake limiting valve not a brake bias valve they are different items. Ray

titan3c · Posted: Sun Jul 05, 2015 5:30 am Post subject:

What size are the connections?

raygreenwood · Posted: Sun Jul 05, 2015 6:54 am Post subject:


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