Leak Down Testing Poll
- Thread starter rich1
- Start date
One would assume pressure. Other than the smoke trick, I'm not sure how one would detect a vaccum leak. Nor, the benefits of doing so. Since your engine "sucks" air, I feel the pressure test to be the best option, as it more accurately recreates the engines natural asperation. There's a nice thread on building a pressure tester if you don't already own one. I built mine from randomness around the shop and a trip to Home Depot. I vote pressure only. But hey, I've been wrong beofre.
I vote both! As the engine experience both positive and negative pressures during its cycle... in general, a pressure test is easiest to use, and finding the leak is easier too.
The vacuum test is actually pretty important, as that is where you lean condition will come from(air getting pulled into the cranc case)
Seals could possibly fail in one direction only too (not too common but does occasionally happen)
If possible, do both, otherwise use the pressure test.
The vacuum test is actually pretty important, as that is where you lean condition will come from(air getting pulled into the cranc case)
Seals could possibly fail in one direction only too (not too common but does occasionally happen)
If possible, do both, otherwise use the pressure test.
Either or. I use pressure because it much easier than figuring a vacuum leak tester. Plus with a vacuum you would need smoke to pinpoint a leak as you cant see bubbles inside the engine.. Although the engine works like a small compressor sucking air in and creating a vacuum of its own a vacuum test would be more inline of what the motor is actually doing. However its much easier and more practical to use pressure..
Pressure test. I agree that a vaccum test may be better, but the leak will be harder to detect. The worst thing that can possibly happen is the pressure will create a leak. At that point the seal would be close to failing anyway. That's my .02
Seals could possibly fail in one direction only too (not too common but does occasionally happen)
I have seen this before. The seal and or gasket was working like a reed. It would open up when there was suction and close when the pressure reversed. They can also be temperature sensitive. Talk about a head scratcher ..
I have seen this before. The seal and or gasket was working like a reed. It would open up when there was suction and close when the pressure reversed. They can also be temperature sensitive. Talk about a head scratcher ..
Seals could possibly fail in one direction only too (not too common but does occasionally happen)
I have seen this before. The seal and or gasket was working like a reed. It would open up when there was suction and close when the pressure reversed. They can also be temperature sensitive. Talk about a head scratcher ..
Exactly , most of the time either one can work . Its the head scratchers that are a pain .
