I am investigating a new vacuum leak on the old truck I bought a view months ago. I have read numerous threads hear and have gained quite a bit of info. Yet I am wondering if I need all of the vacuum tubing that is present. If not, what can be removed/rerouted? There are no emission requirements to meet. It has dual exhausts, so if there were cats, they have been removed. Any thoughts?

 

Most of it can be removed, just remember you need the line for the vac advance, PCV valve and the stuff for the heater control.

Welcome to the Forum and being the newest Georgia Chapter Member !!!

 

Don't forget to check all the vapor management stuff as well...charcoal canisters to fuel vapor purge line, etc. Mine had lines everywhere.

A Mityvac would be a great tool for checking for a vacuum leak - just don't go overboard on the suction so you don't damage anything.

There are all sorts of things that can leak...the environmental has blend door actuators that are all vacuum powered...

...and the automatic environmental, if you have that, is all vacuum powered, but as stated above, the very basics are distributor vacuum port (should be off of carb), brake booster, and PCV valve.

Check all vacuum lines for cracks and tightness.

 

Thanks for the info! I finally had a chance to take a look. I found the port off the carb, the port off of the intake manifold, and the port off the distributor. What do you mean by environmental and automatic environmental? There is a strong vacuum off the intake manifold, but very weak off the carb. Also, there is not a hose off the PCV. Where should that hose run?

 

PCV (from the filler cap) goes to vac port on the carby, the clean air intake from the rocker cover on the other side of the engine at the rear, goes to the air cleaner.