It leaks slightly when the water gets hot the paste seems to go softer and sticky. I am thinking next time I will use Permatex RTV Ultra Grey Rigid high torque silicone gasket maker instead. It can be used as a gasket dressing or in place of a gasket. Any suggestions on if is best to use it as a gasket replacement or as a gasket dressing would be appreciated ?. Also I noticed that the gasket looks slightly different on each side. Does it have to go on a certain way ?.

 

I don't know about whether the gasket you are using is supposed to go in a certain way - can you tell by how it fits or mates up to either the thermostat elbow or the housing?

The Permatex Ultra Grey should work with or without a gasket, as long as you give it time to cure. Twenty-four hours would be best. And as always, the surfaces of the thermostat elbow and housing must be clean and dry before you apply the sealant. I would suggest drying both parts, then spraying them with brake cleaner to remove any residual grease or coolant. Allowing them to dry completely before applying the sealant and reinstalling the thermostat.

Hope to hear good news in your next post!

Cheers,

Don

 

I done it again with hylomar red 100 gasket sealant and no leaks at all. Then when the paste got hot it started leaking out again. It seems when the paste gets hot it goes soft and water manages to leak out from wherever it can. I have ordered Permatex ultra grey rigid high torque rtv silicone gasket maker. When it arrives I will do the job again. I am just not 100% sure if to use a gasket and use it as a gasket dressing or just use no gasket. I was thinking to do it without a gasket as it is a gasket maker.

The instructions are below but I was not sure how long to leave it until I tighten the bolts properly as it does not say. Any suggestions would be helpful ?.

For best results, clean and dry all surfaces with a residue-free solvent such as Permatex® Brake & Parts Cleaner.
Cut nozzle to desired bead size. Gaskets are best formed using a 1/16" to 1/4" (2 to 6 mm) bead.
Apply a continuous, even bead of silicone to one surface, surrounding all bolt holes. Assemble parts immediately while silicone is still wet. Finger tighten until material begins to squeeze out around flange. Allow to dry for one hour then retighten 1/4 to 1/2 turn.


For best results, clean and dry all surfaces with a residue-free solvent such as Permatex® Brake & Parts Cleaner.
Cut nozzle to desired bead size. Gaskets are best formed using a 1/16" to 1/4" (2 to 6 mm) bead.
Apply a continuous, even bead of silicone to one surface, surrounding all bolt holes. Assemble parts immediately while silicone is still wet. Finger tighten until material begins to squeeze out around flange. Allow to dry for one hour then retighten 1/4 to 1/2 turn.
Permatex® Ultra Grey® Rigid High-Torque RTV Silicone Gasket Maker

 

Hi Mat,

I would suggest trying the procedure exactly as given by Permatex. Install the thermostat and cover while the Permatex Ultra Grey is still wet, and tighten the screws by hand (using a socket with your fingers would be fine to improve your grip on the heads of the screws, but don't use a ratchet or breaker bar on the socket). Allow the sealant to dry for one hour, then retighten the screws 1/4 to 1/2 turn (whichever seems to feel right). Because the Ultra Grey cures to a very rigid state, the actual final torque of the screws is somewhat less important, but you don't want to overtighten the screws and squeeze out too much sealant.

I don't believe you need the gasket with Ultra Grey, but do allow it to dry overnight before adding coolant and starting the engine. 24 hours would be even better.

Please let us know how it goes.

Cheers,

Don

 

Thanks Don for your advice. Do you have any suggestions on how to keep the thermostat in the thermostat elbow ?. Sometimes it falls out while putting it all back together. I sometimes wish the thermostat housing was up right instead of sideways.

 

A few tips I can think of that may be helpful:

1. Reinstalling the thermostat elbow and thermostat is easier if the radiator hose is not connected to the elbow and is tucked out of the way. You can reinstall the hose after the thermostat is installed.

2. One way of assembling the parts is to apply sealant to the elbow mating surfaces and lay the elbow somewhere convenient within reach (with the sealant facing up, of course). Install the thermostat in the thermostat housing on the engine, and if necessary hold it in place with a long, thin flat-bladed screwdriver. Now bring the elbow up into alignment with the housing and just before the sealant on the elbow comes into contact with the housing, withdraw the screwdriver as you push the elbow home.

3. If the above fails, clean and dry the housing and elbow again. Install the thermostat in the housing and apply a strip of tape to hold it in place. Now put a few small dots of sealant around the perimeter of the thermostat flange and wipe off any sealant that extends outward beyond the mating surface of the housing. Do not apply the sealant to any of the moving parts of the thermostat. Allow the sealant to cure for an hour or two, then carefully remove the tape to ensure the thermostat remains in place. Apply sealant to the elbow and install.

Cheers,

Don

 

I put water in the car and no leaks so far so it looks like the rtv silicon gasket paste saved the day. Thanks for everyone's advice and support with this issue I had.