77 trans vacuum
Team Owner
Joined: Jan 2006
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From: Crossville TN
Assuming that you have a transmission with a vacuum modulator, you simply connect it directly to a manifold vacuum source (ie, fitting on the intake manifold would be best). But, you must remember that any significant length of rubber vacuum line (over 8" or so), has the potential to collapse under full manifold vacuum. So, a short piece of rubber line from the intake manifold fitting and a short piece from the vacuum modulator, with a metal tube (3/16" or 1/4") running between them would work just fine.
P.S. Do NOT connect it to the line feeding the power brake diaphragm or to the line going to the base of the carb from the PCV and/or the fuel vapor canister.
P.S. Do NOT connect it to the line feeding the power brake diaphragm or to the line going to the base of the carb from the PCV and/or the fuel vapor canister.
Last edited by 7T1vette; Oct 27, 2016 at 11:48 PM.
Team Owner
Joined: Jun 2000
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From: Southbound
Cruise-In II Veteran
For AT, most C3s use the same manifold vacuum port as the headlights. A short piece of hose on the port connects to a metal line down to the modulator where a second short piece of hose connects to the modulator.
Last edited by Easy Mike; Oct 28, 2016 at 07:19 AM.
Safety Car
Joined: Oct 2007
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From: Seattle Area Washington
The assembly manual for the 1977 model is a great investment.
