What's the proper way to do a leak down test?

I have an 06 450 that I need to do a leak down test on. What is the correct procedure? Do I need to disengage the auto decompress? I have done this on other engines.

Thanks

The engine is locked down at TDC/C and then they pressurize the combustion chamber with air through a fitting in the spark plug hole. This fitting has a gauge. Then they measure how long it takes for certain amount of air to leak out. Its done in a percentage of leakage. At the same time they can also tell where most of the leakage is coming from. Air from the exhaust means exhaust valves are leaking. Air from the carb. means intakes are leaking. Air from the crank case means rings/cylinder are leaking. Air from the radiator means head gasket or cracked cylinder/head.

The engine is locked down at TDC/C and then they pressurize the combustion chamber with air through a fitting in the spark plug hole. This fitting has a gauge. Then they measure how long it takes for certain amount of air to leak out. Its done in a percentage of leakage. At the same time they can also tell where most of the leakage is coming from. Air from the exhaust means exhaust valves are leaking. Air from the carb. means intakes are leaking. Air from the crank case means rings/cylinder are leaking. Air from the radiator means head gasket or cracked cylinder/head.

I'm familiar with what a leak down test is. I've done them plenty of times before. What I was looking for was more a step by step for my particular application. Like how to lock my engine at TDC? Is there any need to disengage the auto decompressor? Things like that. I do appreciate the description of what a leak down test is and how it works:thumbsup:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now