Proper sealant for Rad hose change & intake manifold change ?

[David K.]

Gentlemen;

Planned works for my 65'-365 when it comes out of hibernation next month; are:
1. New upper and lower radiator hoses.
2. Removal of intake manifold and valve covers (aluminum) for adjustments, etc.. I will be installing new gaskets on the intake, as well as new cork gaskets on the aluminum valve covers.
3. Rebuilt GM (....326) water pump from Bill Mock.
4. Thermostat housing gasket change.
When I install the new hoses, as well as the new gaskets on the above mentioned items - I have heard of the following sealing products:
1. Permatex Ultra Copper RTV
2. Permatex number 2
3. Blue silicone

Any advice on what product(s) to use ? Is there a brand and type of sealer which I have omitted ?

Thanks in advance

[James W.]

Re: Proper sealant for Rad hose change & intake manifold change ?

David,

I use the Permatex Ultra Copper or the hi-temp Permatex red silicone sealant on my valve cover gaskets. I would recommend the Pematex Form-A-Gasket for the thermostat housing and the front ant rear intake manifold gaskets. The Permatex Ultra-Black woukld be a good choice to use on/at the joints of the intake manifold to head to block for added oil leakage control.


I'm sure there will be other that can give you some further tips.


Regards,

James West

Gentlemen;

Planned works for my 65'-365 when it comes out of hibernation next month; are:
1. New upper and lower radiator hoses.
2. Removal of intake manifold and valve covers (aluminum) for adjustments, etc.. I will be installing new gaskets on the intake, as well as new cork gaskets on the aluminum valve covers.
3. Rebuilt GM (....326) water pump from Bill Mock.
4. Thermostat housing gasket change.
When I install the new hoses, as well as the new gaskets on the above mentioned items - I have heard of the following sealing products:
1. Permatex Ultra Copper RTV
2. Permatex number 2
3. Blue silicone

Any advice on what product(s) to use ? Is there a brand and type of sealer which I have omitted ?

Thanks in advance

[Dave C.]

Re: Proper sealant for Rad hose change & intake manifold change ?

I just installed everything you are talking about, and after searching old threads and talking to everyone I know, that's in the know, I think the common opinion on the intake installation is to throw away the end gaskets and just use a bead of sealant instead , I used Permatex " the right stuff" and was very happy with the results. I also used the white Permatex thread sealant on all the intake bolts, as I know from experience that they will seep oil if you don't .

[Ara G.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Also, I use sealant on the inside of the upper and lower radiator hoses before I install them to ensure no leaks from them either. Repro clamps don't bite down like the originals. Did it with all 3 of my 67's and not a leak yet (from a hose that is....lol)

[David K.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Thank you guys. I'll buy all of them ASAP !

[Gary B.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Also, I use sealant on the inside of the upper and lower radiator hoses before I install them to ensure no leaks from them either. Repro clamps don't bite down like the originals. Did it with all 3 of my 67's and not a leak yet (from a hose that is....lol)

Ara,

What specific sealant did you use inside the hoses?

Gary

[Ara G.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Gary, I will check tonight when I get home as I can't remember off the top of my head, but I think it was permatex blue. Works fantastic. Makes sense too, why not put it on the inside of the hose ends to prevent any leaks. An "old timer" taught me the trick. Did it with my 69 Camaro BB and same result - never a leak. Will post the brand tonight. Hope all is well with you Gary...Regards. ARA

[Duke W.]

Re: Proper sealant for Rad hose change & intake manifold change ?

I think guys go overboard on sealants. Maybe with a few exceptions, I don't think they were used when GM assembled the engines.

For paper or composite gaskets I wipe down the surfaces with silicone spray lube. This will make them easier to remove if the component has to be replaced. If you want the gasket to stick to the removed component, like a water pump, just wipe down the surface that mates to the engine or use a little gasket cement on the side that mates with the removeable components.

For coolant hoses I use a VERY THIN film of silicone grease, which will help seal and prevent the hose from seizing to the nipple.

For valve cover gaskets, especially on mechanical lifter engines where they must be removed periodically for valve clearance adjustment, I use gasket cement to secure them to the valve covers and wipe down the opposite side with silicone spray lube. This way the covers should pop off with the gasket intact, and it will usually last for at least the next one or two cycles. The biggest problem with valve cover gaskets is overtorquing. This will overcrush the cork and cause leaks. The spec is 24-48 INCH-pounds. Start at the lower end of the range, and then retorque them to the mid-point after a few heat cycles.

Duke

[David K.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Hi Ara;

Waiting with great anticipation for your confirmation of the sealant used on the radiator hoses !

Thanks; David

[Ara G.]

Re: Proper sealant for Rad hose change & intake manifold change ?

Hi Ara;

Waiting with great anticipation for your confirmation of the sealant used on the radiator hoses !

Thanks; David

David, my apologies for taking so long to get back to you. My magnificent little 11 month old daughter keeps my attention. With her birthday coming up on 4-27, yes she was born on 427, we've been busy. I used Permatex Hylomar HPF gasket dressing and flange sealant. Got it at Pep Boys. Works fantastic. Hope this helps! Be well. Ara