'67 GT-500 HELP on Vacuum connections

Picture of choke tube and fresh air filter below. Brake booster vacuum taken from short metal tube screwed into the fitting on the back of the intake just under the back of the rear carb. The modulator valve vac is taken off of a small vacuum nipple protruding from that same fitting . If you can't find one PM me I can set you up with that and the rare fresh air filter too. Bob

 

Hello Bob, Thanks for the help in the past! Not to steel this thread but what size is the brake booster line going from the back of the intake? I currently have a 5/16" line on there, is that too small? I'm having a lot of booster issues on another thread! Thanks for the help, Matt.

 

If you don't use hose rated for vacuum, it has the possiblity to suck closed. Could be part of the booster problem. This hose has thicker walls.

 

Thanks roddster! I will look into that as well. My booster has two ports on the vacuum tree, a small and a large? Would connecting to the larger one hurt? The motor stumbles right now when I really jump on the brakes so I do think the booster is working but not enough! Thanks again, Matt

 

Sometimes a symptom of engine stumbling or dying is a sign of a faulty brake booster. A ruptured internal diaphragm allows outside air to be sucked into the engine . The amount of the tear or rupture to the rubber diaphragm would determine how bad it is . I have seen some that have such a big tear that you hear a bad hiss when the brakes are applied and others that it even kills the engine when the brakes are applied other ones have been to lesser degrees when the brakes are applied as you discribed in your situation. I think the metal line is 3/8. I will not be able to take any pictures and post them until at least Monday night.Bob

 

A thought occurred to me that you may not have rebuilt the choke furnace on the exhaust manifold before installing the engine in the car. If it has never been done there is a 99.995% probability that it is clogged up. If clogged and the engine is installed in the car the choke will not function and you will have to adjust it at the carb to fully open all the time. No chance of fixing it on the car IMHO. It wouldn't work but will look the part. Bob

 

Hey Bob sent you an e-mail. Thanks!! Matt