Cooling system gaskets..use sealant?

[CMB]

I just replaced timing belt, front main and camshaft seals, and water pump and thermostat. Started filling the radiator up with coolant and noticed a steady drip leak from the thermostat housing mounts to the back of the water pump, although I can't rule out that it is coming from the heater return pipe junction. I used toyota paper gaskets on all junctions when doing this job. I cleaned all mating surfaces of old gasket material. I did not use any permatex or any other gasket sealer. So that is my question...should I use sealant along with paper gaskets? Is there any particular junction involved here that is prone to leaks? BTW, I also replaced the two o-rings on the bypass pipe with new o-rings. I hate that I am going to have to disassemble this now.

[xirdneh]

i have found sometimes that replacing the "O" rings is not enough
they leak for some reason
so i have had to take it apart and put it back together with sealant added
this has happened several times so now i goop 'em up everytime

[4wdchico]

I always make sure that a thermostat housing mating surface is flat by surfacing it gently on sandpaper on a flat surface. If you are highly skilled, a mill file can be used also. Usually the housing will be bowed at the mounting holes, making the the area between them slightly concave. I usually use Permatex High Tack sealer mainly to keep a gasket from moving around during assembly. My heavy artillery gasket sealer is Permatex #2 non-hardening sealer. I have never had it leak, amazing stuff. As with any sealer, don't overdo it.

[xirdneh]

. My heavy artillery gasket sealer is Permatex #2 non-hardening sealer. I have never had it leak, amazing stuff. As with any sealer, don't overdo it.

thats the stuff i use

[CMB]

Finally got it back together with gasket sealer. No leaks! I followed 4wdchico advice on sanding thermostat housing flat. It was clearly warped after I got it on a flat surface. decided 120 grit is the way to go with a quick follow up of 200. I used gasket sealer on the thermostat housing, the bypass tube o-rings, and the sensor housing bypass thing to head.

Thanks for the help!

[dlb]

what's next on your tercel to-do list, carson? i imagine you must be close to having it all buttoned up.

[CMB]

Yup. I am getting getting there...but now, I am now dealing with a little shudder when accelerating up hill, about 25 mph to 35 mph.