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Leaking manifold gaskets

stuart

Member
"I have a 73 F31 Trojan with 3

"I have a 73 F31 Trojan with 318 Chryslers

Had water in the oil - pulled the Exhaust manifold which was full of water

Bought new gaskets - connected manifold and elbow outside the boat.

Connected a garden hose to the inlet on the manifold and turned it on. - all 3 ports on the manifold remained dry.

When I cranked up the water faucet, high, water appears in the port beside the elbow.

My question is that no matter how high I crank up the water faucet pressure should no water appear in the exhaust ports. (maybe the manifold and the elbow are not designed for this much pressure)

Thanks"
 
"It could have leaked back fro

"It could have leaked back from the riser IF you had that attached as well. If you didn't, then no way should water come out the ports.

I'd make up some block off plates (1/4 " steel) and pressure test the assembly before putting it back on. Fill the manifold with colored water--windshield fluid works great--and put about 10 pounds of air pressure on it. If that sucker's gonna leak, you'll know about it! Stuff white paper towels in the ports and check 'em for wetness.


Jeff"
 
Thanks for the reply

I did


Thanks for the reply

I did put a block off plate on. First on the manifold itself and there was no leakage.Then up at the top of the elbow( riser) There was leakage in the first port in the manifold.

I will check the gaskets again and use your suggestions

Thanks
 
Here is what I tried

I took


Here is what I tried

I took the elbow and stuffed paper towel in both the exhaust tunnel and the casting passages. Taped the entire face of both mounting surfaces. (not the holes)

I then pump water into the upper hole (garden hose) for about 5 minutes. When I took the tape off every piece of paper towel was soaked. I did the same for the other Elbow and it was dry.

I did another test by taping over these passages - stuffed paper towel into exhaust tunnel - turned the hose on and waited 10 minutes. -removed the tape and the paper towel was dry

I then got two gaskets that covered the passages. Attached the elbow to the manifold and blocking plate- turned the water on through the manifold.- the test lasted about 2 minutes as water was leaking into the first port. This only happens when I crank up the water pressure.- I dont know what PSI I am pumping into the manifold but I know that it is more than what the water pump is pumping

Conclusion - I have a bad elbow that has an internal leak.

Thanks
 
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