Anybody know what that huge vacuum line going from my intake manifold to a canister near my master cylinder is? I have a 71 transporter, and if I didn't know any better I would swear it had power brakes.
And if it did have power brakes how would I keep that vacuum line hooked up with dual carbs or a proggy or something?
Lee
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One of these days ill get this stuff right!
73 Super, 2110, 120 cam, 2x 44 IDFs Hyfire CDI and some more fun stuff.
71 Transporter, soon to be a dog hauling, camping luxury wagon (or something like that)
Power Brakes?
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Marc
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Power Brakes?
Your stock `71 bus intake manifold had a large vacuum penetration below the carb (just like an AutoStick bug manifold). There's a check valve in the line near the engine. If you use a progressive (yeccchh!) you'll need to drill & tap the manifold for a brass fitting.
With duals that are designed to have an equalizer tube (Solex), insert a T-fitting into it and connect the vacuum hose there.
For duals that don't use an equalizer (Webers, etc.) I ordinarily get a second check valve and a T-fitting and put the check valves on the manifold sides of the T.
Be sure to use reinforced hose that's designed for the job - regular hose will collapse - expensive new but usually pretty cheap from a wrecking yard (waterpumpers are a good source).
With duals that are designed to have an equalizer tube (Solex), insert a T-fitting into it and connect the vacuum hose there.
For duals that don't use an equalizer (Webers, etc.) I ordinarily get a second check valve and a T-fitting and put the check valves on the manifold sides of the T.
Be sure to use reinforced hose that's designed for the job - regular hose will collapse - expensive new but usually pretty cheap from a wrecking yard (waterpumpers are a good source).
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Lees73Super
- Posts: 506
- Joined: Thu Nov 08, 2001 12:01 am
Power Brakes?
I'm pretty sure I will be staying with the single solex I took off. I was just curious. The existing vacuum line is in good shape and the check valve is still there. Before I pulled the engine the brakes seemed to be working good. I still intend on replacing all of the pads, shoes, and flexible lines, and may also rebuild the wheel cylinders and calipers.
So my 71 bay does have power brakes?
Thanks for the info.
Lee
So my 71 bay does have power brakes?
Thanks for the info.
Lee
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Jeff T
- Posts: 279
- Joined: Wed Jun 12, 2002 12:01 am
Power Brakes?
Yes,your 71 has power brakes.More like vacuum assisted brakes.If you have your foot on the brake pedal when you start it,you will feel it sink a bit. JT
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Marc
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- Joined: Thu May 23, 2002 12:01 am
Power Brakes?
I hear that the fluid tank atop the master cylinder is no longer available for the `71/`72 busses, so if the M/C needs replacement you might want to change it over to the `73 style.
Biggest issue on bus brakes is usually rotors that are too thin (the pads will bottom out in the calipers without contacting the rotors). New they're 13mm thick and you're not supposed to turn them past 12; the wear limit is 11.5mm. If you need to replace calipers, again it's worthwhile to move up to the `73 parts since `71/`72 stuff is getting rare.
Rear brakes went through changes almost annually so be sure your shoes are correct for the backing plates whatever year you use.
The maximum diameter cast into the drums is based upon being able to achieve a satisfactory radius match with standard off-the-shelf linings. It is legit to go .040" larger IF you have thicker linings custom-made.
Biggest issue on bus brakes is usually rotors that are too thin (the pads will bottom out in the calipers without contacting the rotors). New they're 13mm thick and you're not supposed to turn them past 12; the wear limit is 11.5mm. If you need to replace calipers, again it's worthwhile to move up to the `73 parts since `71/`72 stuff is getting rare.
Rear brakes went through changes almost annually so be sure your shoes are correct for the backing plates whatever year you use.
The maximum diameter cast into the drums is based upon being able to achieve a satisfactory radius match with standard off-the-shelf linings. It is legit to go .040" larger IF you have thicker linings custom-made.