Best Sealant for Plastic thermostat housing on Perkins engine

[will_mck]

As above the plastic thermostat housing has failed again on a 4 cylinder Perkins engine, last one only lasted a year and a half, gonna replace this with a brand new one. I was wondering what is thee best Gasket Sealant for putting it all together. Need something with lots of flex as it must harden eventually and leak. It's a pain in the backside, you'd think Perkins would make a replacement upgraded metal thermostat instead of the plastic ones. Anyway what's the best Gasket Sealant for these thermostat housings?

 

[Stock]

https://hylomar.com/

 

[Speedstar]

Do not over tighten it

 

[ACEngineering]

As above the plastic thermostat housing has failed again on a 4 cylinder Perkins engine, last one only lasted a year and a half, gonna replace this with a brand new one. I was wondering what is thee best Gasket Sealant for putting it all together. Need something with lots of flex as it must harden eventually and leak. It's a pain in the backside, you'd think Perkins would make a replacement upgraded metal thermostat instead of the plastic ones. Anyway what's the best Gasket Sealant for these thermostat housings?

Rust is the problem!
The block rusts and distorts the plastic.

Wire brush on a die grinder and get it spotless to start with. Then the newer plastic housing with silicon seal not oring.

Decrease it and pain on some brown loctite gasket dressing. Leave it to go off almost dry. Then assemble.

Then remove bolts one at a time and apply small amount of copper slip to the shank of bolt.

It's the only way I get them to last.

 

[ACEngineering]

As above the plastic thermostat housing has failed again on a 4 cylinder Perkins engine, last one only lasted a year and a half, gonna replace this with a brand new one. I was wondering what is thee best Gasket Sealant for putting it all together. Need something with lots of flex as it must harden eventually and leak. It's a pain in the backside, you'd think Perkins would make a replacement upgraded metal thermostat instead of the plastic ones. Anyway what's the best Gasket Sealant for these thermostat housings?

You can still buy an aluminium housing to the head if you want too that uses apaper gasket! Still uses the plastic top though.