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Vaccume line trouble shooting

how do you perform the baby powder test to check for vaccume leak? what do you look for?

Never heard of it. Sounds a little messy.


I’ve not heard of the baby powder thing either, but there’s a lot I’ve never heard of.

I have always used a stethoscope - listening for hiss - and/or an unlit propane torch, feeding propane around all of the vacuum lines/fittings.

I’ve heard of this one years ago but it’s pretty vague. Never seen it done nor have I tried it.

The best method in my opinion is to connect a vacuum gauge to the intake manifold and verify that there really is a leak as a first step.

If a leak is shown then start pinching off vacuum lines (or plugging them on hard plastic) one at a time until the leak disappears. That puts you on the right vacuum circuit.
I use an old pair of surgical forceps for hose pinching. Needle nose pliers will work but may be more prone to ruining an older hose.

Just get a couple of cans of carb. cleaner and start spraying at likely spots,when the idle goes up you have found it,what out for those secondary ignition leaks.

Baby powder is for coolant leaks or oil leaks. On an old bomb, you can find many vacuum leaks by looking for hoses that are cracked at the ends. Hardened hoses will be the most likely ones to have cracked ends.

OK you have all the vacuum leak tests,what is the problem with the car? what year Dodge caravan? any codes? why do you suspect vacuum leaks?

“vacuume/vacuume leak” is what always came up. 2002 dodge caravan sport. the check engine light pops on & when we have it read "vacuume/vacuume leak is what the reader thing says. we have replaced the gas cap as instructed but no luck yet…

What is the actual code that comes up - the “P” number? Such as P0123.

You are referring to a vacuum leak detected in the EVAP system by the engine computer. It was assumed that you were referring to vacuum leaks on the engine. They are completely different systems.
You can tell us the exact trouble codes, can’t you? We have our own decoder rings; so, just the letters and numbers, is fine----such as: P0320, etc.

We all got burned by another post with too little info.