What is the best way to find a vacuum leak?

 

Honestly....and this isn't what you asked for, but buy about 20 feet of rubber hose, a few vacuum t's, a few vacuum elbows/adapters and take an afternoon and follow the vacuum diagram and replace the now brittle factory vacuum hose bundle.

 

You'll spend more time and pull out more hair looking for the leak rather than just replacing all the lines, and being sure you wont have multiple leaks. Next leak i get this is definitely what i will do

 

I used starting fluid, sprayed it one the vacuum lines... it's supposed to change the idle when you hit a leak... didn't work for me, but I did hear the leak slurping it up.

some say the starting fluid approach is too dangerous because it is flammable. I guess shops can do a "smoke test" or you can use a stethoscope to listen for sucking sounds

 

I use carb cleaner... ... Starting fluid.. is pretty stout lol

 

Propane works too, like from a copper-plumbing torch or whatever. Also check around the intake manifold seals

 

Very good thoughts from all...thank you.

I do like the idea of just replacing all the lines.

 

I can look but anybody know the size off the top of youe head? 1/8" or 5/32"... Or both

 

I'll say!

 

You will need probably both size vacuum hoses. If I remember correctly, I used majority 5/32, but had to use a few vacuum adapter fittings to adapt it to the smaller 1/8 to ensure it fit tightly and securely. Also, I didn't run the new hoses around the back of the engine with the lone exception of the hose that runs to the diverter valve behind the upper intake manifold.