Pressure Testing Imco exhaust manifold
 

Anyone have a simple, cheap, yet effective method of testing manifolds for leaks?? One of my valves shows signs of water leakage and I'd like to test the manifolds this winter.

Thanks,

Kirk

Kirk, I pressure tested my Stainless Marine manifolds. They were still installed on the boat. I removed the hose that goes from the manifold to the riser/exhaust pipe, inserted an air fitting into the hose as it was still connected to the manifold and put 15 psig of air on the manifold and waited to see if there was any leak down.
Not sure what setup you have but it's a matter of sealing of the water chamber and pressurizing. Don't need to use a lot of air pressure as you could damage the manifold.
Good Luck, Russ

Testing Manifolds
 

Kirk,

I have found in the past you need to be careful regarding how much pressure you put into the manifolds.
An easy inexpensive test that I have been doing for years is:
1. Remove the manifold from the boat.
2. Look into each cylinder to see if you can spot any evidence of water contamination.
3. Put the manifold on a bench, position it so that the water will come out the exhaust tip and not flow back into the manifold.
4. Install a brass shut off valve on the end of the hose so you can control the water flow.
5. Put a HOT WATER HOSE on the line that feeds the manifold. Turn the water on and look into all the exhaust ports especially the one that you have found evidence of water in.
6. Typically the gasket between the exhaust exbow and the manifold is the problem area. Or the elbow has rotted out.
Good Luck post your findings.
Brian

Thanks
 

Both a good methods, I'll try the water method first, might be easier to notice where the leak is from.

Thanks Brian and Russ.:)

how do you test the pipes? i don't know how to close off the inside of the pipe where the water dumps into the pipe.

It would be a good idea to get them up to temp, a leak may appear when the metal is expanded. As a side note here is an excerpt of a conversation I was privy to at a boat shop;

Customer calls in wanting a reseal kit for a Bravo. Third kit he has bought this week. We inquire if he has trips, no a single. Ok whatever comes and gets the parts.
Next day calls complaining that the kit is junk. Ask why he says this. Third reseal and drive still fails pressure test. Ask him what pressure he is using. He says not as much as it is supposed to because his air compressor is not that strong. OK how many pounds of air are you using, oh about 120 psi!

Why? Well he called another shop (previously wore that mechanic out with questions) and they said to pump it up to 15 or so to pressure test. He interpreted this as 215 or so! Lucky that case was not a grenade! Be careful how you listen.
TimT.

Kirk,
I made a comment regarding using hot water to do your test of the manifolds. The reason for the hot water is to get the system as close to the operational world as possibe with out spending a lot of money.
When your test the manifolds test them assembled to the elbow or exhaust pipe.
Do not break the elbow away from the manifold, because you want to test this area to see if it is causing you the problem.
Post your findings.
Thanks Brian