tstat housing leaking...suggestions?
Thread Starter
Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
tstat housing leaking...suggestions?
I have a stock looking chrome t-stat housing/water neck on my 509 engine. Got it from Summit don't remember what brand but it has the stupid 0-ring groove. Well of course the o-ring doesn't fit the groove right and pinches last winter and leaks all over the place. So I filled the groove with silicone and put a standard water neck gasket in there. Now it leaks around the bolts that come up thru the water neck.
I put silicone on the threads and rebolted but i'm still getting the antifreeze up thru the bolts.
Any suggestions?
I wanted to get my car to the Englishtown swapmeet/car show this saturday but i won't have a new water neck by then. Hoping to pick it up at the show if i need a new one.
Any suggestions on a fix for the time being?
Also anyone know if this will fit under the L88 hood on a big block?
Any thoughts if this will fit our vette setup?
http://store.summitracing.com/partde...5&autoview=sku
U think the above water neck would cause more harm then good? I understand about our low radiators and air in the system but wouldn't the 90 degree design cause more flow turbulance in the coolant which would effect your cooling efficiency?
I put silicone on the threads and rebolted but i'm still getting the antifreeze up thru the bolts.
Any suggestions?
I wanted to get my car to the Englishtown swapmeet/car show this saturday but i won't have a new water neck by then. Hoping to pick it up at the show if i need a new one.
Any suggestions on a fix for the time being?
Also anyone know if this will fit under the L88 hood on a big block?
Any thoughts if this will fit our vette setup?
http://store.summitracing.com/partde...5&autoview=sku
U think the above water neck would cause more harm then good? I understand about our low radiators and air in the system but wouldn't the 90 degree design cause more flow turbulance in the coolant which would effect your cooling efficiency?
Last edited by 68 NJConv 454; Apr 17, 2008 at 12:25 PM.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
is the chrome pitted on the underside? If so you may not be able to get it to seal up regardless of what you do.
On both of my cars, the '65 and the '78 I have the stock cast t-stat housings. I use the GM T-stat housing gaskets that have the O-ring in them (GM part # 10105135 if I'm not mistaken), than put a bead of Permatex also as an extra precaution, and use permatex on the threads of the bolts to keep any coolant from wicking up them.
I don't get any leaks on both cars using this method.
On both of my cars, the '65 and the '78 I have the stock cast t-stat housings. I use the GM T-stat housing gaskets that have the O-ring in them (GM part # 10105135 if I'm not mistaken), than put a bead of Permatex also as an extra precaution, and use permatex on the threads of the bolts to keep any coolant from wicking up them.
I don't get any leaks on both cars using this method.
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
I know exactly what water neck you have and I know your problem all too well. It is a Mr Gasket brand, another "quality" product from Holley. The chrome on the bottom cracks and peels and nothing will make it seal. I got a stock replacement from Autozone cheap, painted it to match the block and have been trouble free ever since. God bless, Sensei
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The chrome is too slick to seal. Yep. That's right. That nice, smooooth surface will 'leak like a sieve'. Take it off the engine, then put a piece of 250-400 grit sandpaper face-up on your work bench, and go at it. Just enough to rough up the surface. Work it a couple of different directions to generate a cross-hatched pattern. Then put a gasket on it and put a light coat of Permatex gasket sealant on both sides. Bolt it down and let it set for an hour or two. Fire it up and go. Oh...forget the silicone sealant on engine water joints.
Racer
Joined: Oct 2005
Posts: 469
Likes: 0
From: West Slope of the Sierras California
I, too, had problems sealing my chrome t-stat housing. After several attempts, I put a straight edge across the bottom of it and you wouldn't believe how bad it was. Like mentioned, I 'resurfaced' it on the bench using graduating grits of emery cloth. It took awhile but got it flat and sealed.
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Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
NAPA Part # BK 6051044
The only thing I did to it was mill the tops of the bolt holes so they are parallel to the gasket mating surface. May seem ****, but it was a trick I started using back in the 60's that I still use. I never cracked a housing since I started doing it - I determined back then that it was the main cause of these things cracking and to me, I proved it to be true! I also feel it distributes the force of the bolts better.
Thread Starter
Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
I know exactly what water neck you have and I know your problem all too well. It is a Mr Gasket brand, another "quality" product from Holley. The chrome on the bottom cracks and peels and nothing will make it seal. I got a stock replacement from Autozone cheap, painted it to match the block and have been trouble free ever since. God bless, Sensei
Good advice guys.
I'll try the sanding method. If that doesn't work...of i go to napa. Or I might just pick up a gm unit from the englishtown swap meet tomorrow.
Thanks for the advice
