• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

thermostat/goose neck leaking- help!

Bundy

Bronco Guru
Joined
Jan 10, 2009
Messages
2,045
on the 302, i am trying to put a new t-stat in but everytime i finally get it in it leaks. it's a Coolflex radiator hose that connects to the manifold and when i took it off intially there was just this o-ring.

the o-ring doesn't appear to be in bad condition, is there something i am missing? i tried running it with the regular 302 paper gasket and the o-ring, but that leaked too.

any ideas? also any tricks to getting that damned t-stat lined up/in the right position or just alot of swearing etc?
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,312
Get rid of the o-ringed water neck and get one that uses a real gasket.
 

1970mule

Bronco Guru
Joined
Dec 20, 2007
Messages
1,515
also i had that problem not to long ago, do u have a aluminum intake manifold? if so maybe one of the screw holes are stripped? and it is not tightening all the way down.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,821
Chrome thermostat housing with O-ring?
If so get rid of it and get a normal thermostat with a paper gasket. Those O-ringed chrome jobs always leak. I can't think of how many of those I have seen with massive amounts of silicone around them trying to seal them up. Sounds good on paper. I never reearched it but I think the housings warp and can't maintain the pressure needed to seal the O-ring. But a large flat paper gasket weals just fine with a normal housing.
 

charvey9

New Member
Joined
May 27, 2008
Messages
49
Loc.
Beaverton, OR
I had this problem recently too, and found out that the thermostat was slipping out of position each time I tried bolt the water neck back on and caused the rubber seal to leak.

The last time i put it together I used high temp instant gasket sealer on the T-stat to hold it in place and it has worked fine ever since.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Get an origonal equipment gasket style housing. Check the housing gasket surface with a straight edge. They get warped when overtightened. You can flatten the surface satisfactorily with a fine flat file then finish with emery cloth on a flat surface. Make sure the bolts aren't too long and bottoming out preventing the housing from pulling up tight. A bit of gaskasinch on the gasket to hold the gasket and thermostat in the housing while youre assembling it and you're set.
 

SteveL

Huge chevy guy
Joined
Jun 24, 2001
Messages
11,602
Loc.
Hawthorne ca
those chrome aftermarket housings suck. Like stated above, get an original replacement and you'll be fine.
 

fordguy

Contributor
Bronco Guru
Joined
Jan 23, 2005
Messages
5,493
exactly those o ring jobs are worthless ask me how i know. i threw the one i had away.
 

toddz69

Sponsor/Vendor
Bronco Guru
Joined
Nov 28, 2001
Messages
10,063
any ideas? also any tricks to getting that damned t-stat lined up/in the right position or just alot of swearing etc?

One trick I learned recently for holding the t-stat in place is to loop a piece of dental floss through the t-stat and hold it tight while you're installing the housing and tightening the bolts. Once they're sufficiently torqued, just pull the dental floss through and you're good to go.

I had a leaking t-stat housing about a year and a half ago that no paper gasket seemed to fix. I ended up using the Permatex product for sealing it up and it held for about a year before it started leaking again.

I ended up spending the big bux on a nicely machined aluminum neck (Billet Specialties) with the o-ring and so far (3-4 months) it's holding just fine. If it starts leaking again, I'm going to replace my manifold :-[ .

Todd Z.
 
OP
OP
Bundy

Bundy

Bronco Guru
Joined
Jan 10, 2009
Messages
2,045
haha, i love the fact that i can come on here and post something lame the PO did and have at least 5 people with the same story.

funny, the guy at Orange Engine also snickered when i asked him for the o-ring and he mentioned what a POS the chrome housings were- he also suggested the standard housing.

for now i just used a thin bead of rtv sealant and it's holding for now. for sure replacing the housing before any big trips.
 

Jeff10

Contributor
Bronco Guru
Joined
Feb 20, 2011
Messages
2,137
Loc.
Indianapolis
Hey blubuckaroo,

Get an origonal equipment gasket style housing. Check the housing gasket surface with a straight edge. They get warped when overtightened. You can flatten the surface satisfactorily with a fine flat file then finish with emery cloth on a flat surface. Make sure the bolts aren't too long and bottoming out preventing the housing from pulling up tight. A bit of gaskasinch on the gasket to hold the gasket and thermostat in the housing while youre assembling it and you're set.

I'm fighting with a leaking thermostat housing. I have tried a little RTV on both sides of a paper gasket initially, and it leaked. I tried nothing but the paper gasket and it leaked.

I read your post about the Gasgacinch, and looked online at the product description. Are you still a fan?

I suspect that the thermostat is moving slightly. (Using the RTV was the poorest result. I searched this last night in other boards... opinions ranged from no RTV to RTV only to RTV and paper.)

I'll look for some Gasgacinch tomorrow.

Thanks

Jeff
 

savage

Contributor
Bronco Nut
Joined
Apr 18, 2007
Messages
2,482
Loc.
Renton
Mine was leaking on my 302 and it ended up being the bypass connection on the thermastat housing,the steel part thats pressend was leajking so I bought a new 3/8 connection and put sealer on it and pressed it in where the old one was,no leaks so far.
 

Jeff10

Contributor
Bronco Guru
Joined
Feb 20, 2011
Messages
2,137
Loc.
Indianapolis
Hi,

I purchased High Tack Gasket Sealant by Permatex. I used the sealant on the gooseneck side of the gasket. That held long enough for me to install the gooseneck without the thermostat moving. The gooseneck isn't leaking at the mating surface, although a couple of the new hoses are weeping a little and need to be tightened.

The High Tack seemed to work pretty well.

Jeff
 

savage

Contributor
Bronco Nut
Joined
Apr 18, 2007
Messages
2,482
Loc.
Renton
Ive been having trouble with the housing on my rebuilt 302.Ive tried different houseing from murrey brand,to Mr Gasket and have had no luck they all have leaked.Im thinking of retrying my old one,Ive read they make a sealent just for this issue but I cant find it.Has any one hurd of this sealent?Im stuck on how to fix it.I have a new EdleBrock manifold and the face is flat so you would think it should have a good seal.
 

ransil

Bronco Guru
Joined
Sep 6, 2003
Messages
8,122
For holding gaskets I use yellow weather strip adheasive ( aka monkey snot)
 

baddad457

Sr. Member
Joined
Aug 24, 2011
Messages
560
haha, i love the fact that i can come on here and post something lame the PO did and have at least 5 people with the same story.

funny, the guy at Orange Engine also snickered when i asked him for the o-ring and he mentioned what a POS the chrome housings were- he also suggested the standard housing.

for now i just used a thin bead of rtv sealant and it's holding for now. for sure replacing the housing before any big trips.

Nest time you take it off, take a piece of rough sand paper and rough up the chrome finish on the gasket surface, then use a gasket, place the T-Stat in it's recess, smear a thin coat of RTV over it, then place the gasket over the RTV. Then bolt it back in place. It's not the housing that's the problem, but the chrome. It's too slick to get a good seal with anything. If it's an O ring housing, fill the O ring groove with RTV when you apply it, then enough RTV to make the gasket stick to the housing
 
Top