Thermostat Housing Leaking

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Alan J Odze

Alan J Odze

AJ
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Location
Middletown NY
I have a 70 340 with the Eldebrock Performer RPM INTAKE.

I replaced a chrome thermostat housing that had a slow leak. I replaced the gasket with a new one and switched it around from back to front. So it leaked in the same spot.

I went out and bought a Billet Housing with the O ring. Put it all together and low and behold this housing was worse than the other. Out of curiosity I removed the hosing again and left the thermostat out and didn’t use silicone. Low and behold there were no leaks. So I removed the Billet housing and put in the thermostat and when I did this it leaked again. It seems that the thermostat raises the housing to allow air/water to escape and not seal.

I am at my wits end and lost my patience with this. Do I have to use a specific Eldebrock housing with this intake manifold?

Thanks in advance for any help.
 
Realgasket.com
Read and follow the directons.
Not a drop in 3 years using oem repo t stat housing and 54 year old manifold
 
if the thermostat doesn’t fit in the recess in the housing it will never seal correctly.
As stated above check the diameter of the T stat.
 
I had a chrome one that wouldnt seal. I took a block with sand paper and trued the bottom of it and sanded the chrome off the bottome in the process. Never leaked again. Im convinced the a/m chrome plating makes the bottom not so flat.
 
cudascott said:
if the thermostat doesn’t fit in the recess in the housing it will never seal correctly.
As stated above check the diameter of the T stat.
Click to expand...
The thermostat fits perfectly in the housing. But I called Summit and got a really nice person on the phone. Just as I was about to hang up he said he found a caption about Eldebrock said to use only early model housings on the intake manifold. $ 11.00 part. Nobody told me this before. And I ordered the Billet through them. But nobody looked at the caption from Eldebrock about early model housings only. None work after 1992. Thanks for your post.
 
Alan J Odze said:
Thank you. I will order that gasket forthwith
Click to expand...
Remember... FOLLOW THEIR INSTRUCTIONS, no matter how much you just cant bring yourself to not crank down on the bolts. Also be sure your bolts are not too long or there is crud packed in the bolt hole cavity.

you will need an inch pound torque wrench. DON'T tighten it by the "that's about right" method:)
 
Dana67Dart said:
Remember... FOLLOW THEIR INSTRUCTIONS, no matter how much you just cant bring yourself to not crank down on the bolts. Also be sure your bolts are not too long or there is crud packed in the bolt hole cavity.

you will need an inch pound torque wrench. DON'T tighten it by the "that's about right" method:)
Click to expand...
Thank you
 
Alan J Odze said:
I have a 70 340 with the Eldebrock Performer RPM INTAKE.

I replaced a chrome thermostat housing that had a slow leak. I replaced the gasket with a new one and switched it around from back to front. So it leaked in the same spot.

I went out and bought a Billet Housing with the O ring. Put it all together and low and behold this housing was worse than the other. Out of curiosity I removed the hosing again and left the thermostat out and didn’t use silicone. Low and behold there were no leaks. So I removed the Billet housing and put in the thermostat and when I did this it leaked again. It seems that the thermostat raises the housing to allow air/water to escape and not seal.

I am at my wits end and lost my patience with this. Do I have to use a specific Eldebrock housing with this intake manifold?

Thanks in advance for any help.
Click to expand...

take a hard look , and a file to the mounting surface , probly been overtightened and warped ----
 
I tried making the surface flat too. I think that it laughed at me. Get the Real Gasket and torque it to 15 in lbs, think that's what it is, just follow their directions. Quality product.
 
I’ve found that it’s very easy to get the thermostat a little off centre and thereby lift the housing and cause a leak. I reach through the top of my billet housing while I snug down the bolts and make sure that I can still turn the thermostat, this makes sure that it is centred properly.
 
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FYI

SUMMIT RACING RESEARCHED THIS PROBLEM FOR ME. THE SALESMAN FOUND A CAPTION FROM ELDEBROCK THAT SAID ONLY 1992 AND OLDER OEM THERMOSTAT HOUSINGS WORK ON THIS MANIFOLD.
I BOUGHT AN OEM HOUSING AND THERMOSTAT AND THIS SOLVED THE PROBLEM.
STAY AWAY FROM AFTERMARKET CHROME.
COST $ 9.99 for housing and 9.99 for thermostat.
No leaks.
Thank you to everyone responding back.
Al
 
Cal Tonsley said:
I’ve found that it’s very easy to get the thermostat a little off centre and thereby lift the housing and cause a leak. I reach through the top of my billet housing while I snug down the bolts and make sure that I can still turn the thermostat, this makes sure that it is centred properly.
Click to expand...
Thanks
 
Glad that worked for you, it did not for me.
Tried the different housing thing, no go.
The Real Gasket performed as advertised.
Guess ya gotta do what ya gotta do.
 
CRUZE 418 said:
Glad that worked for you, it did not for me.
Tried the different housing thing, no go.
The Real Gasket performed as advertised.
Guess ya gotta do what ya gotta do.
Click to expand...
Do you have the Eldebrock Performer RPM?
Summit said OEM has to be before 1992.
I was going to go the Real Gasket if this failed. I called up East Coast Speed who are down the road from me and they knew crap.
Chrome housing are not comparable with this particular Eldebrock.
Thank you for your response.
Al
 
Cal Tonsley said:
I’ve found that it’s very easy to get the thermostat a little off centre and thereby lift the housing and cause a leak. I reach through the top of my billet housing while I snug down the bolts and make sure that I can still turn the thermostat, this makes sure that it is centred properly.
Click to expand...
I tried that as well. Before I torqued the bolts. But I think East Coast Speed sold me the wrong thermostat. The one from Summit was different. And they guy from Summit checked the part number from ECS and said the thermostat was wrong. I just gave up on the Billet after Summit said Eldebrock calls for the OEM housing. Lesson learned.
 
I have a '70 Six-pack manifold, stock thermostat housing. It has the large thermostat and housing, got the thermostat from Flowkooler (Robert/Shaw). There is no room for the o-ring housing, the thermostat and bolt holes are right next to each other. So there must be manifolds out there that are using a smaller thermostat and housing that would allow a machined groove and o-ring.
 
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CRUZE 418 said:
I have a '70 Six-pack manifold, stock thermostat housing. It has the large thermostat and housing, got the thermostat from Flowkooler (Robert/Shaw). There is no room for the o-ring housing, the thermostat and bolt holes are right next to each other. So there must be manifolds out there that are using a smaller thermostat and housing that would allow a machined groove and o-ring.
Click to expand...
Stock manifold? Or Eldebrock?
 
Stock manifold is an Edelbrock, off of a T/A or AAR 340.
 
I ordered the billet housing from Billet Specialties. I had been fighting a leak for a year after MULTIPLE attempts. I think I paid $40 or $50 for it, but it WORKED!!! I can't imagine a billet housing for $11 that would be worth a crap, but let us know.
 
Dana67Dart said:
Realgasket.com
Read and follow the directons.
Not a drop in 3 years using oem repo t stat housing and 54 year old manifold
Click to expand...

THIS solved my problem with a difficult to seal manifold and now it's all I use.... and yes FOLLOW THE DIRECTIONS!!!
 
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