Bubble Test – Used In Conjunction With A Cylinder Leak Down Test

Bubble Test - Used In Conjunction With A Cylinder Leak Down
Bubble Test - Used In Conjunction With A Cylinder Leak Down

So, To determine the health of a head gasket between two cylinders try doing a bubble test.

If you believe you have a leak, but just cannot find it, Doing a bubble test may be the answer.

There are occasions when either a compression or leakdown test will not show a very minor leak. Especially, When the leak is hidden between the cylinder sealing surfaces.

When you do a leak down or compression test there is always some leakage. It may be from ring or valve, So doing the bubble test may be the answer.

Bubbles In Water
Bubbles In Water

It is done in conjunction with a cylinder leak down test.

Bubble Test With Cylinder Leak Down Test
Bubble Test With Cylinder Leak Down Test

Bubble Test – How To Do It ( Seven Easy Steps )

Step-1

The first thing you have to do is remove all the spark plugs.

Step-2

Use a cylinder leak down tester and hook it up to one of the cylinders.

Step-3

Apply 100 psi of air pressure to that cylinder.

Step-4

Use another hose from a compression tester and hook it up to the adjacent cylinder.

Step-5

Place that second hose in a container of water and look for bubbles in the water.

Step-6

If there are any sealing issues, bubbles will be seen in the water.

Step-7

So, This must be done in all cylinders. Since, There may be an occasion where the gasket leaks only in one direction.


Though this condition is rare, it must to be understood that the purpose is to diagnose a problem. Consequently, No assumptions or short cuts can be taken.

Look For Bubbles In Water
Look For Bubbles In Water

So, There is no pressure reading with the bubble test, only a visual confirmation of bubbles in the water.


Helps Find Very Small Leaks In Many Places

  • Sometimes there is a very small leak in a cylinder wall. ( From cracks or perossidy in cylinder )
  • Incorrect cylinder sleeve installation. ( Possibly too much crush causing a cylinder to distort and leak )
  • Blown Gasket or leak between cylinder ( Gasket, cylinder damage or cylinder head damage )
  • Even a (MLS) gasket leaking internally. ( Because of multiple layers of material )
  • Damage to a cylinder from hydrolocking ( Water injected to a cylinder from flooding )
MLS Head Gasket With Layers
MLS Head Gasket With Layers

Conclusion

So, If you really believe that there is a leak between cylinders on your engine, Try doing a bubble test. The primary use of the bubble test is when all other tests fail. Finally, Easy to do and you most likely already have the necessary tools.

Please Share DannysEnginePortal News