Checking for vacuum leaks refresher
Mountain Pass
Joined: Apr 2000
Posts: 102
Likes: 0
From: Arkansas
Checking for vacuum leaks refresher
When trying to pin point a vacuum or air intake leak I believe I remember hearing or reading about spraying something that will cause the idle to increase when the substance is sucked in by the problem area. Any suggestions or ideas? Thanks!!
Senior User
Joined: Feb 2002
Posts: 470
Likes: 1
From: Mount Prospect, IL
Checking for vacuum leaks refresher
I use WD-40 to test for vacuum leaks. I start slowly, and doing as you say, I spray it on one hose/fitting at a time. If there is a vacuum leak then when the WD-40 hits it, it does cause a slight increase in idle. If I find a leak, I fix it, and continue to check for leaks. (often times I find there is more than one, so I dont stop until I have finished the entire job)
The other good thing is that as I wipe up the excess WD-40, it gives me a chance to clean the areas I sprayed.
good luck
Drew
The other good thing is that as I wipe up the excess WD-40, it gives me a chance to clean the areas I sprayed.
good luck
Drew
Elder User
Joined: Feb 2000
Posts: 601
Likes: 1
From: South Sioux City, NE USA
Checking for vacuum leaks refresher
I've heard of using a spray bottle of water to look for leaks also. Instead of the engine revving up, it will bog down.
I think I would feel safer spraying water instead of something
flammable. IMHO
Roger Lane
I think I would feel safer spraying water instead of something
flammable. IMHO
Roger Lane
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Senior User
Joined: Feb 2002
Posts: 470
Likes: 1
From: Mount Prospect, IL
Checking for vacuum leaks refresher
I would be sceptical of water in checking for a vacuum leak. I think that trace amounts of moisture would be undetectable, and as a result you would probably miss a small leak.
Thats just my $0.02.
Drew
Thats just my $0.02.
Drew
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Lead Driver
Joined: Nov 2000
Posts: 6,624
Likes: 342
From: Albuquerque
Checking for vacuum leaks refresher
A small hose hooked to a propane source works really well. To get the engine to speed up you have to feed it something combustible but keep it away from the air cleaner or you'll get a false reading.
