thermostat housing leak

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lil red

lil red

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what does everyone use on their housings?

I switched over to a chrome housing and can't get the f%&king thing to seal against my LD340 intake - the old aluminum housing sealed perfect.

I've machined the surface of the intake to remove a little pitting

I've machined the backside of the housing to remove the chrome plating - though maybe that was an issue

I've used gaskets (factory ones), gasket adhesive, sealant and even stuff from work called chesterton 860 with a spray activator at 500 bucks a kit.

.......still leaks.....even when the damn trucks cold sits all winter

I'm thinking of taking the housing to work and machining an o-ring groove in it.....opinions?

thanks guys
 
I've had a couple Mr. Gasket chrome ones that always sealed well with the O ring on them but took them off during tear downs and couldn't find new O rings again.
 
a lot of sealing issues with the chrome ones.i was lucky and got one that sealed.put your old one back on or buy something else besides the chrome one.i like your idea of the o ring.i wish i was that skilled.
 
Those intakes have 2 sets of bolt holes and all 4 holes go into water. I think that is where the problem comes from. Plug the unused holes and use sealant on the bolt threads.
Many will overtighten the bolts which squeezes out all the sealant and compresses the gasket and doesn't give it a chance to swell and seal. Even with stock intake and water neck I will evenly tighten the bolts to something like 15 foot pounds ( guess ) and I have had a small seepage for a few days. It does stop leaking completely though.
 
I had the same leak on my LD340 when I bought my Dart last year. When I took it apart over the winter I assumed it was because of the old thermostat housing so I bought a new chrome one too. Likely the same one you have.
I'm just in the process of reassembling the engine and now I'm wondering if I'll still have the same problem that you're having.
I like you're o ring idea. I just might look into doing that now while it's still apart.

Ted
 
redfish....I think mine only has one set of holes, and I thought they were blind and not through holes, but I'm gonna take it off this afternoon and check that, thanks

thanks everybody....good responses as always
 
pauly said:
I've had a couple Mr. Gasket chrome ones that always sealed well with the O ring on them but took them off during tear downs and couldn't find new O rings again.
Click to expand...

Go out and buy a longer o-ring the same diameter as your old one, with a razor blade cut it to the size you need and use a dab of krazy glue on the end.

Kenny
 
.....................maybe ur intake is porous.........I use aviation form a gasket along with the gasket ............kim......
 
i put mine in the lathe and cut an o ring in it and that fixed it.
 
Those chrome thermostat housings always seem to leak, including mine, so I removed it and placed a straight edge across the sealing surface, and quickly realized these things are not very flat. I chucked mine up in a milling machine, and removed about .015 just to get it flat, and now it seals fine. I'm sure these are cheap china junk, but can be made to seal ok.
 
lil red said:
I switched over to a chrome housing and can't get the f%&king thing to seal against my LD340 intake - the old aluminum housing sealed perfect.
Click to expand...


Everything you need to know can be found right there.


Aluminum against aluminum looks great. Media blast your stock one and put it back on.
 
I switched over to a chrome housing and can't get the f%&king thing to seal against my LD340 intake - the old aluminum housing sealed perfect.
Click to expand...


theres your problem.. the chrome one always leak.
 
fanofpetty said:
Those chrome thermostat housings always seem to leak, including mine, so I removed it and placed a straight edge across the sealing surface, and quickly realized these things are not very flat. I chucked mine up in a milling machine, and removed about .015 just to get it flat, and now it seals fine. I'm sure these are cheap china junk, but can be made to seal ok.
Click to expand...

check my original post
 
I am not the seller...I bought the last two they had listed...lol

another guy got them listed but for a "few dollars more"....
 
RedFish said:
Those intakes have 2 sets of bolt holes and all 4 holes go into water. I think that is where the problem comes from. Plug the unused holes and use sealant on the bolt threads..
Click to expand...

THIS is where the trouble lay with mine. I found a CAST IRON outlet at the local O'Really store.
 
I threw away my gasket and used the burnt orange Permatex and mine is leak free.
 
Use a stock aluminum mopar one.
I have had alot of problems with stock cast iron ones.
When you put it on use a Fel-pro gasket greased with permetx on both sides.
Let it set for 24 hrs before adding coolent. You have to let it set 24 hrs.
It will not leak.
 
I know that this is an old thread but here's an update. I used the aftermarket one pictured below and it leaked badly. The first thing that I did was take it to work and true up the gasket surface on the lathe. WOW this thing was way out!
I reinstalled it and it leaked again but just a trickle. So I took it off again and re-machined it. This time I did what we've been doing on Harley Davidson cylinders for years. I turned a small step (.005" high) onto the gasket surface. You can see the red line in the photo. That's the step. I reassembled it with Permatex and let it sit overnight. It is now perfect.
I hope this helps.


Ted
 

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