K so I have been working on this 96 blazer with the 4.3 engine since the morning, going on 6 hours now. I managed to figure out how to change the thermostat which I havent done yet cause I gotta empty the rad.
My question is how the hell do I turn that little white peice that is the stopper for the drain? I have fiddled with it for 3 hours almost and I went and bought the repair manual but it tells you crap. Someone please help me out ASAP cause its gonna get dark in a few hours and I was hoping to get this done cause tomorow its gonna rain lol. Thanks.

 

It has a 1/4" square recess in it. Use a 1/4" extension on a 1/4" ratchet. If I remember correctly, it's only a 1/4 turn fitting. Turn it too much and it'll come right out.

 

I figured it out 5 mins after I posted this thread lol. New question, what happens if I pull it right out? Does it lose its seal when I put it back in?

 

Just reverse what you did to take it out, nothing else has to be done.

 

Well I got the system back together and now its dark so I guess tomorow if its not raining I will fill the system back up with fluids in the rad and so on.
Question I have though is the burping part. I was told that the rad needs to be burped but I dont know how to do that.
Can someone fill me in on what to do on the burping or anything else that needs done before I take it on the road.
Thanks.

 

It's not the safest method, but as long as your careful you should be safe. I have not had an issue yet with air staying trapped by doing it this way

I fill the system as much as I can and wait a few minutes for it to burp itself.
Then I get in, turned on the heat to full and started the engine. With the radiator cap off I let it run and just watch the water/antifreeze level.
As it drops, just keep adding and giving it some throttle. Don't be stingy because as much pressure and circulation you can get from the pump the better. As temperature starts rising, water will start pouring out at you(if you keep and eye on it, you should be able to cap it before any is lost) and that is when you can cap it.
I run the throttle from the engine bay so I can keep an eye on the level and time when I need to get the cap on.
As you let it continue up to operating temperature, the overflow tank should start filling(make sure there is a bit in there to begin with) and any air in the line should be pushed out and you're all done as soon as it comes up to operating temp.

 

I never drain mine when I replace the thermostat. I just take the housing loose and let what's in there run out, only lose a very small amount and very little air gets trapped in there.

I read a good tip on here someplace. If you DO drain it you should fill it back up til it's right at the opening where the thermostat goes, before you put the thermostat in, that way most of the air will be pushed out the opening.

 

Ok last question, I put the thermostat in and so on but on the thermostat it has a black rubber gasket that just sits inside the housing attached to the thermostat. Now the housing itself is just a metal to metal contact when I bolt it on.

Question is should I be spooging a bead of Permatex Thermostat housing RTV gasket goop on the metal of the housing or can I get away with the way it is now?

I hope I dont have to use the RTV cause then I would have to take it apart again, even though its a 10 minute fix but its raining outside.

Thanks everyone for your help to a NOOB.

 

The gasket has a groove all the way around the inside of it, the thermostat fits in that groove. Don't use sealer on it.

 

Wouldnt the sealer make a better seal just incase the housing doesnt sit flush together?