thermostat housing leaks

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red cuda

red cuda

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i cant seem to get a good seal on my 318. i have a chrome water neck housing, with a 180 degree thermostat.mounting to an edelbrock intake. i have tried hi temp, silicone, used up all my spare gaskets. am i missing something here? all surfaces seem to be flat.
 
Take a square sheet of 120 or so sand paper lay it on a flat surface like a glass table. Then while holding the housing from the top use light down presure and make figure 8's on the paper, this will sand off the chrome and insure a flat bottom. May take a full 5 to tem min to get all chrome off and flat. Them make sure all surfaces are dry and cleaned off wit carb cleaner, new gasket with something like permatex #2 or gaskacinch (sp)?? I don't like silicone at the t-stat base. Make sure where the head of the bolts touch are flat and use flat washers there if posible.
 
EL5DEMON340 said:
Take a square sheet of 120 or so sand paper lay it on a flat surface like a glass table. Then while holding the housing from the top use light down presure and make figure 8's on the paper, this will sand off the chrome and insure a flat bottom. May take a full 5 to tem min to get all chrome off and flat. Them make sure all surfaces are dry and cleaned off wit carb cleaner, new gasket with something like permatex #2 or gaskacinch (sp)?? I don't like silicone at the t-stat base. Make sure where the head of the bolts touch are flat and use flat washers there if posible.
Click to expand...

^^^^^^ Sand it flat,,
 
If you only put the RTV 50/50 around the edge of thermastat itself and the lip of the intake where it sits and use about a 3/16 bead and put it on wet it won't leak.
A lot of people make the mistake of putting the RTV all over the entire contact surface and not where it really matters.
I do all mine this way and NEVER have so much as a damp spot.
It also won't even matter if it's perfectly flat.
 
buff the bottom of the housing and use primseal type 3
i have never had a problem
 
I have used the gasket dry, with nothing at all on them even with the chrome housing after sanding the bottom.
 
red cuda said:
i cant seem to get a good seal on my 318. i have a chrome water neck housing, with a 180 degree thermostat.mounting to an edelbrock intake. i have tried hi temp, silicone, used up all my spare gaskets. am i missing something here? all surfaces seem to be flat.
Click to expand...
I had the exact same issue. Chrome Mopar water neck and Eddy intake. After the second try, I ditched the chrome and got a water neck from autozone. I used a gasket and a thin layer of RTV. When I first fired it up (after sitting for 48 hours), it started to leak ever so slightly.
The leak seemed to go away after it warmed up. I'm going to keep an eye on it and replace if needed. Anyone know how the water necks are with the O rings? any better?
 
red cuda said:
i cant seem to get a good seal on my 318. i have a chrome water neck housing, with a 180 degree thermostat.mounting to an edelbrock intake. i have tried hi temp, silicone, used up all my spare gaskets. am i missing something here? all surfaces seem to be flat.
Click to expand...

trash that chrome crap.. get a stock style or a billet one and be done with it.
 
equium said:
I had the exact same issue. Chrome Mopar water neck and Eddy intake. After the second try, I ditched the chrome and got a water neck from autozone. I used a gasket and a thin layer of RTV. When I first fired it up (after sitting for 48 hours), it started to leak ever so slightly.
The leak seemed to go away after it warmed up. I'm going to keep an eye on it and replace if needed. Anyone know how the water necks are with the O rings? any better?
Click to expand...

The one on the Barracuda is an o-ringed housing from Terry's Auto Lab. I got tired of the leaky cast iron housing, so I spent the $100 for the good one. I'll put one on my Valiant if it shows any signs of leaking.
 
lilcuda said:
The one on the Barracuda is an o-ringed housing from Terry's Auto Lab. I got tired of the leaky cast iron housing, so I spent the $100 for the good one. I'll put one on my Valiant if it shows any signs of leaking.
Click to expand...
OK. Enough beer for me. It took me a few minutes to realize it was you, Lee. lol
I was thinking, "Hey, his user name is my license plate". lol.
Yeah, I'm finally wrapping things up on my son's valiant. It still needs a few things (Oil Pan and Transmission gaskets, and more fine tuning), but he can finally drive it to school. I'm going to check out Terry's auto lab. thanks for the info.
 
Fel-pro gasket and Indian head and that is all you need.:thumleft
 
I have the exact same problem. Lol just alittle trickle of antifreeze from the water neck. Chrome neck and a edelbrock airgap intake.
 
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