Brake Booster - 71 Bus

antmantbone · Post by **antmantbone** » Fri Apr 25, 2008 7:05 pm

Hey, I'm a new guy and have looked at a few posts about the subject, but still need some help.

I have a new 1776 engine that I'm putting in my 71 bus. It doesn't have the taps for the power brake vacuum line. It has dual Webers. Can someone link me to the type of fittings I will need to put in. From what I read on here, I can just put it on the 1-3 intake, is this correct? Someone mentioned something about a check valve - what is this needed for, and can someone link me to an example of this?

Thanks in advance.

chitwnvw · Post by **chitwnvw** » Fri Apr 25, 2008 8:33 pm

You need a check valve somewhere in the brake booster line.

You can get this

191-611-933 Vacuum Check Valve, Bus/Pickup/Vanagon 71-91 $14.30

From these guys:

http://www.bus-boys.com/

But you may be able to find something from a local shop. A check valve is a fairly common device, just needs to be able to fit snuggly in the vacuum hose.

I put my vacuum port in one cylinder (iirc number 3) but a lot of guys do it to 1 and 3. My seems to work fine. You can decide.

As far as fittings go, you just need to find something that will fit snuggly with your booster hose. Drill the manifolds, and JB Weld it in.

Pics courtesy of adventurewagen:

vdubyah73 · Post by **vdubyah73** » Sat Apr 26, 2008 3:39 am

Instead of JB Weld, which is a great product, choose your fittings and buy a tap for the threads on those fittings. Then drill, tap, and loctite the new fittings in place. How many heat and cool cycles will JB Weld go through with out failing? Threads and loctite would be easy to repair, in a pinch, compared to trying to epoxy something back together 50 miles from nowhere.

antmantbone · Post by **antmantbone** » Sat Apr 26, 2008 1:59 pm

You guys rock, thanks for the help.

Post by **Amskeptic** » Sun Apr 27, 2008 7:54 am

antmantbone wrote:You guys rock, thanks for the help.

I am chiming in late. . . . hello? where is everybody? Tap both #1 and #3. You do not want to have the radical intake vacuum pulses from just one cylinder yanking at the brake diaphragm and annoying the control valve inside the booster, nor do you want a minor vacuum leak turning the exhaust valve on that one hapless cylinder into a puddle of melting metal. VW went through the expense and aggravation of plumbing both sides of the engine for a reason.
Colin

antmantbone · Post by **antmantbone** » Sun Apr 27, 2008 10:54 am

Thanks Colin.

So if I tap the manifold where 1 and 3 are combined, it should be fine? Would there be any need to "tee" the two manifolds together?

Post by **Amskeptic** » Sun Apr 27, 2008 1:29 pm

antmantbone wrote:Thanks Colin.

So if I tap the manifold where 1 and 3 are combined, it should be fine? Would there be any need to "tee" the two manifolds together?

Where one and three are combined?

Tap the right front manifold and the left front manifold. Run the brake booster vacuum supply off the common pipe that connects the two together.
Colin

antmantbone · Post by **antmantbone** » Sun Apr 27, 2008 1:41 pm

Duh....I had a brain fart for a second. This makes sense. Thanks for the help.

Forgive my cerebral flatulence - I'm new but trying to do this the right way, with my own two hands and a lot of help from people who know better than I.

Post by **Amskeptic** » Sun Apr 27, 2008 1:46 pm

antmantbone wrote:Duh....I had a brain fart for a second. This makes sense. Thanks for the help.

Forgive my cerebral flatulence - I'm new but trying to do this the right way, with my own two hands and a lot of help from people who know better than I.

We

in the Itinerant Air-Cooled Kingdom do not condone self-flagellation and scraping deference in any of our subjects. It is Our Experience that We All screw up and get confused somewhere. For example, I melt into crying jags with the Schedule C Form 4562 Depreciation and Amortization.
Colin