vacuum system

[arkusvt]

The pump on #3018 has a steel pipe running from the manifold T to the right hand port, looking at pump from front of engine, that has an integral 1/4" pipe, connected with a short rubber tube. the other port, just to the left, is a hole, with a loose fitting 1/4" pipe just inserted into hole with no resistance to keep it there. It proceeds down and under engine to connect to T and leads to frame tube. Curious as to what held tube in place 68 years ago. I'll epoxy mine. I'm guessing this 2nd port is a booster for vacuum under load but would it negatively affect any of the other dependent systems in line except for wiper speed if it was eliminated? I'm 3 months in on this fascinating/frustrating project and try to learn and understand something every day. The forum posts are a true gift! thank you.

[Barry Wolk]

The pump on #3018 has a steel pipe running from the manifold T to the right hand port, looking at pump from front of engine, that has an integral 1/4" pipe, connected with a short rubber tube. the other port, just to the left, is a hole, with a loose fitting 1/4" pipe just inserted into hole with no resistance to keep it there. It proceeds down and under engine to connect to T and leads to frame tube. Curious as to what held tube in place 68 years ago. I'll epoxy mine. I'm guessing this 2nd port is a booster for vacuum under load but would it negatively affect any of the other dependent systems in line except for wiper speed if it was eliminated? I'm 3 months in on this fascinating/frustrating project and try to learn and understand something every day. The forum posts are a true gift! thank you.

I wouldn't epoxy anything. The pipe is held in place by vacuum. If you're concerned you can use a sealant. However, there is an excellent vacuum-tester, the engine. This is my preferred test. Using a flammable carb cleaner simply spray the joints of that connection, or any other. If the engine is warmed up spray a cleaner at the gaskets between the carb and manifold and the manifold to head. The combustable fluid will have an effect on rpm if it's sucked in. If you plug the hose that leads to the washer bottle that will isolate the majority of vacuum operated devices. Using vice grips crush the larger diameter hose running to the brake booster.

By isolating the motor you need to shoot for maximum vacuum at the lowest rpm to first prove your engine's capability to sustain 19-21 inches of vacuum. You'll not be able to tune your car or get anything to work with any less.

Working by process of elimination you can isolate problems. For doing dash work buy a $25 hand vacuum pump to test the rest of the components. The switch for the antenna is often plugged into the vacuum
lines wrong as all 3 are the same size. The "spider valve" well hidden under the LH heater core is another problematic valve. The wiper switch has lines that can be installed backwards causing a vacuum leak by turning the switch on. That one you can hear. If you don't have a service manual you need one as it's the most complex system aside from from the window wiring.

Just out of curiosity both ports on the pump have to be threaded for a Continental pump and slip fit for the Lincoln pump. I've never seen one of each leading me to think the push in one is loose because a
threaded hole is not a tight enough fit to seal it with a push in fitting. Does the push in fitting have a stop on it? If not it may not be an original tube.

[arkusvt]

having zero experience with this, what I appear to see is a swedged in tube on the right, not threaded, with a rubber connection, coming from the manifold. the left one is a non-threaded hole with the under the engine pipe just stuffed into it. haven't tested further. no stop on the pushed in fitting.