Leak Down Testing - Build and Perform

[steves]

Found these videos today, very well made.

http://en.wikipedia.org/wiki/Leak-down_tester

[ame="http://www.youtube.com/watch?v=7UcOn8OEt0Y"]Cylinder Leak Down Tester,How To Build - YouTube[/ame]


[ame="http://www.youtube.com/watch?v=GvG22YMOzUI"]Automotive Cylinder Leak Down Test - YouTube[/ame]

[ygolohcysp]

I like the videos. Posting here so I can find this again! Thank you.

Dan

[steves]

On the Kat, you'll want to perform the test on each of the 4 cylinders, and each of the 4 hit TDC at different points on the crank.

Once you've found TDC on Cylinder #1, you should be half a turn on the crank for each cylinder moving down the line.

[steves]

Why is a leak down test important?
A leak down test will help you identify problems with a motor quickly and easily, and narrow down what's causing it. You can charge the system with shop air after testing, and listen in the intake, exhaust, and oil to determine where a leak is coming from.

But I already did a compression test....
A compression test only tests one thing, whether or not the piston rings are sealing properly. In my experience with these motors, the rings are almost NEVER the problem.

[boomer_95]

on my bike the rings were the problem..... but thenm it did sit for a LONG time without running.. but yes a leak down tester is a very good tool to have.

i made one for myself but didnt bother putting in the restriction like he shows. most of the time when you have to use a LDT its bad enough you dont need the gauge. you just listen to were the air is coming from. but a gauge is good if you are doing either a maintenece (people who are anal about there engines) or if your doing a performance engine

[ygolohcysp]

In my case in particular, if you're buying an engine of unknown condition.