Radiator drain plug

[wishihadacamaro]

I flushed out my radiator, and now my coolant is actually green! No more brown stuff. But, I had great difficulty gettting the radiator drain plug screwed back in properly. I pushed it in as far as it would go, but it still was sticking out. Then I turned it clockwise. But when I started putting coolant in, it started leaking out. So I pressed it in a little more and turned it clockwise a little more. It seems to be holding, but I don't like the idea of it sticking out a little.

Second problem, the new o-ring that came with my thermostat is too large. So I re-used the old o-ring. But when I was pouring coolant in, it appeared to leak a very small amount. But when I started the car, and drove around for 20min nothing seemed to leak. I left the cap off the reservoir overnight, to let air out, and the coolant level did drop. Hopefully that was due to air escaping, and not the two possible leaks that I have.

[TomM96]

Regarding the radiator plug ... {info from my '97} ...
With time/heat/oxidation/accumulated-dirt, valves tend to become sticky , regardless of material composition. Whenever a valve is opened it is good practice to manipulate it (open/shut) until it moves freely. I manipulated mine while draining the flushing fluid and it gradually freed/eased up , and began to move more predictably/freely.

There is a spiral groove which receives a button/guidepin [so the plug needs move in/out WHILE it rotates]. Mine was very difficult to move/rotate over-center- there is a point where the rotation pressure peaks -- where the detent divides between ON/OFF . It is possible that you may need to use a pliers to move the plug into its' securely "closed" position (this is felt as the plug pops past the point of high resistance , into a parked location). Of course , you need avoid breaking (twisting off) the plug/tab !
*
When installing orings , it is good practice to coat/smear/submerge them in whatever fluid they are to seal (here antifreeze) before assembly ... it lubricates things. Lube/grease can be also used to hold the oring in place.
The old thermo oring will probably do fine after it was warmed up -- but the mfgr always suggests renewing them , as they typically become misshapen with use (and/or swollen), so you should keep an eye on it. A spare thermo oring is a handy maintenance item.

[wishihadacamaro]

So I guess it might be a pain to get the radiator plug back in correctly then. It hasn't leaked at all yet, so it should be fine. As for the old o-ring which I am still using, it's pretty much perfectly round. None of it was brittle at all, so it's not too horrible. I will keep an eye on my coolant level just in case. I may buy a new o-ring. Then since I would have to empty the radiator again, I could try to get the drain plug loosened up. But so long as the o-ring doesn't leak I'm not going to bother replacing it.

I have about 3 1/2 quarts of distilled water, 1 quart or so of coolant, and about 2 1/2 quarts of 50/50 premix in my trunk just in case I leak any coolant from anywhere.

[BobbyP]

I removed the lower radiator hose to drain the system quickly... Messing with the drain plug is akin to "opening pandoras box"

[OldNuc]

+1^^ I agree. That drain valve has several problems, hard to reach, hard to turn if its the one with the little handle, easy to break, can only be manipulated from underneath so you get to wear the antifreeze.

Take the hose off, it works.

[wishihadacamaro]

Originally Posted by OldNuc

+1^^ I agree. That drain valve has several problems, hard to reach, hard to turn if its the one with the little handle, easy to break, can only be manipulated from underneath so you get to wear the antifreeze.

Take the hose off, it works.

I opened the drain valve from above. It seemed to work fine while I was flushing it, but it just didn't close back up properly.

[OldNuc]

Thats why you take the hose off and back flush the system. If you get it open, it will not close.

Garden hose into the bottom radiator fitting and flush water comes out the open hose. Take the thermostat housing off and you can really flush it out.