Thermostat housing still leaking

[87RangerXLTct]

I just got done doing a new water pump, thermostat and new radiator. Always had trouble with the oring sealing on thermostat housing. Sure enough slapped it together using permeates thermostat and water pump gasket maker on outside flange away from oring sealing surface followed instructions on package and it still leaks.
I just picked up a new oring and I’m gonna give the thermostat housing off my old engine a shot. Anyone got any tricks to get these leak free?

 

[RonD]

Put housing on a flat surface to make sure it is "flat"
Make sure o-ring slot is clean, it needs to seal on both inside and outside

DO NOT over tighten bolts, it deforms housing/o-ring and no seal, I think most I have seen on a thermostat housing is 15ft/lb which is "snug" not tight
If you have inch/pound torque wrench use it, 180in/lb, 15ft/lb is a little low for ft/lb torque wrenches to be acurate

 

[87RangerXLTct]

Ron thanks for the help! I finally got it to stop leaking, took a Roloc wheel to the intake where the oring seats and got nice and clean. Been a couple days, no leaks yet.