How to: Install power brakes into 1968-1970 Bus (Pic heavy)

[aeromech]

The 1971 bus manifold should look like this

_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[qball]

Gotcha. So I need to find another manifold. What used to connect to this little port? A different carb? Or one of the ports on the carb that has been plugged? Thanks for the info

[aeromech]

I not sure about your question but the port you can see under the carburetor flange is the 12mm vacuum port that Busdaddy was talking about. The power brakes in most cars, including our buses, runs off vacuum which is accessed from the engine induction system. A vacuum hose runs forward from that port to the brake booster (servo) which lives right under the driver on the front beam.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[qball]

Got it and thanks. Busdaddy had pointed out that the image I presented of my left manifold terminus shows a nipple not for the servo's line to connect but for some other (vacuum?) connection. I can research that and find out why it's there. The center of the manifold which you show is different from mine, so perhaps when the engine was swapped the original connection on the manifold was lost so the owner just did without the power assist. The rotten remnant of the line, with what I take to be the check valve, was laying to the side in the engine compartment.
I have a pretty good grip on the system now that I read your post here where you did the conversions. I was initially intimidated by the servo and the other components and didn't want to refurbish it all. Plus, as busdaddy and kreemowheat and desertbusman might recall, I failed to just get the brakes working at all on this bus (I replaced the calipers, cylinders, lines, MC, shoes, adjusted, and bled bled bled to no avail. No pressure, no stop. This was two years ago. Then I wondered if it was absolutely necessary to put the power assist back into play in order to push the brake pedal and pressurize the lines and push the pads against the discs and the shoes against the drums and make the vehicle stop. I don't think that question was ever answered. I just didn't want to replace the assumed-nonworking servo, and the other parts (and now I know I need the manifold) involved only to find I still couldn't bleed the damn system. But I'm now determined to give it a try after reading and seeing what you did on the early Buses.

[qball]

While we are on the subject, can you comment on your setup re:isn't there a pressure regulator mounted behind the MC on the wall? I don't know if that's its proper name. It's adjustable, per manual, and was just another foreign object to me that made me hesitate to hook up the power assist on my 71. It seems that you can do without it in your setup for the early models, no?

[qball]

And I forgot another thing, if kreemowheat is tuning in (or if anyone else knows). Way back when WW started offering new servos and the initial review was terrible. Have they succeeded with a better product since then? Or is rebuild the only way to go?

[aeromech]

That nipple on the intake end piece originally went to the altitude compensator I believe. Most of those have long since been disconnected. The brakes will work without the booster but not very well. You should still be able to bleed them and get good pressure. You might be able to install a fitting into your current manifold like I did here.

_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[aeromech]

[kreemoweet]

[qball]

Hey kreemoweet, thanks a lot. BTW, I didn't mean to hijack aeromech's nice presentation of his upfitting the non-booster to booster Buses; I just saw it and had some issues pertinent to the content.
I appreciate your info, and I addressed you particularly because I thought it was you who presented a review of a Wolfsburg West booster a few years back, wherein you ended up putting your old one back on since initially there were fit issues, and then in application you found the brakes to be unacceptably 'touchy'. Maybe it wasn't you.
Thanks for clarifying the mistake about what I called a pressure regulator; as you say, the manual clearly explains its function relative to a disc-front/drum-rear Bus.
As I told you some time ago, if I do indeed reach an end in my attempt to make this Bus brake properly, I will post it, including whether I buy a booster or have it rebuilt, etc.
And you're right: I haven't established whether my booster is bad since I haven't hooked it up. I just assume so since this Bus has been sitting for several years. Who knows? I'll start with the manifold and the lines and take it from there.

[qball]

[aeromech]

Expensive compared to what?

Having a core rebuilt
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[aeromech]

Did you thread the fitting directly into the mani, or place an insert into an oversized hole?

I drilled and tapped the manifold for the fitting and I can't remember the NPT size off hand. Maybe 3/8"?

I suppose doing this to the end piece would work if the fitting size you use is not too small. The fitting I used above is normally used in hydraulic systems and is a 37 degree flare AN male on one side and NPT on the other. I'm sure you could find a 90 degree fitting with NPT on the one side and a barbed end on the other. Be sure to use the correct power brake vacuum hose which is available at many FLAPS. Gates 27231 15/32" ID
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[qball]

Great. Thanks.

[TomWesty]

[Hikelite]

I'm aware I'm reviving an old thread, but it seems the appropriate place to ask my question. I've searched and searched, and have not found anyone mentioning their solution to a problem related to this conversion.

I have a 68 that I've upgraded to use the front discs from a 71, including the booster, MC, vacuum lines, etc.

Brake system is done, but then....

The stock 14" wheels do not clear the calipers.

Since several people here have done this conversion, what was your solution?

I'd like to maintain the stock appearance with my original hubcaps, but I'm willing to get over that in order to solve this.

We had an idea to get the hoops from a late bay wheel swapped onto my 5x205 centers since they have a different inside profile that was designed to clear the caliper. Problem is, they are just a little bigger then the early bay hoops, so the wheel guy said it won't work.

I'd like all 4(5) wheels to be the same. I'm not interested in having different front and back wheels. I want to be able to rotate the tires, and I'm not carrying 2 spares.

I've been looking at LOTS of wheel threads. If I can't keep my original look, then it seems going with 5x112 wheels (and redrill rear drums) will be the path of least resistance. Is that what the rest of you did?

I also have an idea to get some aftermarket wheels that would facilitate having both bolt patterns drilled in the wheel. For example, I like the look of 'Empi 5-spoke' on buses, so if I get this http://www2.cip1.com/ProductDetails.asp?ProductCode=C32-E251B
It has the same shape they use for the 5x205 version, so I thought I could get the 2nd bolt pattern drilled in the wheels.

I'm sort of at a loss as to what my best option is.

This is one of the last details to get the bus back on the road. Thanks in advance for your suggestions.
_________________
~Kevin

My 1968 Campmobile

[aeromech]

Firstly,
I started this thread. My intention was to show how to make your stock front drum brakes work better by adding a booster. The reason I stayed with drums was to maintain the original front wheels.

You should have done the research needed to avoid your problem now.

I don't have an easy answer for you but know that my friend, Tom Powell, installed discs on his 1969 but he had to use type 1 wide fives on the front which wasn't the best.

Seems to me that the easiest thing for you to do would be to go back to drums in front and keep the booster. They work great and I've done this to several buses and haven't gotten any complaints. Drums do need more maintenance than disc brakes, no doubt. Chasing your problem sounds expensive if you need to go buying new wheels, etc.
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Hikelite]

[aeromech]

I think my reply came off wrong. I'm fine with you posting here. What bugs me is that you went to all that trouble before knowing what wheels you could use and that's a major blunder. I have no idea what you plan to do with your wheels but I can't believe that it's a good thing to have custom wheels that only fit your car. What happens down the road?
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Hikelite]