In changing my coolant this past weekend, I decided to try the drain plug on my PWR radiator, versus just pulling off the lower radiator hose like you normally would with the stock radiator. Naturally, the top of the plastic drain plug snapped off, and while it's still sealing fine, I'd rather not be driving along and have it suddenly decide to fail and dump all the coolant in the middle of nowhere. I knew I should've left it alone...

Are the threads in the drain plug "pipe threads"? Also, any ideas on removing the remains of the plug, other than just drilling it out and possibly having to use a tap to clean the threads out? Is there an aluminum type of drain plug sold anywhere, or is the corrosion factor too much of a problem for aluminum to be used for the drain plug? Thanx in advance.

 

Try going to your neigbourhood rad store and see if they have a plug. You can also ask them how to take yours out without damaging the threads.

R.K.

 

Yeah the same thing happended to me with my stock radiator's drain plug. What I ended up doing was using one of those left handed drill bits to get the remaining drain plug out of there.

 

Had the same thing happen to me about a year ago. I simply used an extractor to draw the thread stump back out. As for the replacement, I used a metal bolt with threads that matched the old threads, but I need to check on corrosion, as you brought up, because I do not know if I used a galvanized bolt or stainless. And either one may still present an issue.

 

Same thing happened to me last week. I used a small steak knife (cheap one not the good ones) and jammed the tip in there and twisted. Worked like a champ.

 

My Fluidyne radiator has one of those funky drains in it. The plug is a two piece brass unit. The center section has left handed threads. This means that you have to turn it the wrong way to loosen it. When you do this, it loosens upward, into the radiator. Of course, there are no directions to indicate how is is supposed to work. The outer section of the plug comes out normally. The entire unit is brass, and is available at hardware stores. If you have not damaged the outer threads, it should be easy to replace the entire unit.

 

pep boys carries Nissan/MAzda Drain *****. $2

 

Every radiator I've ever seen has plain machine threads in the drain hole. In my stocker I use a hex head bolt as I worry about the plastic plug stripping or breaking. I have to use care to be sure I don't overtighten the bolt and strip the threads in the plastic tank though.

A bolt extractor (EZ Out) should get the remains of the plastic plug out fine. To the best of my knowledge radiator drain plugs are pretty standard and universal. Any auto parts store should be able to help with a new one.

Like you I'd be worried about corrosion if using a metal bolt as a plug with an aluminum radiator. Perhaps a stainless steel bolt would work? I'd stick with plastic plugs or perhaps find a nylon bolt.

 

I'm not sure why everybody's concerned about corrosion here. How will a steel bolt cause more galvanic issues than the engine irons? Or are you simply worried about galling on the aftermarket rad's aluminum tank?

 

Because the irons aren't threaded into the housings...
I'm thinking the amount of pressure and tight clearances of both surfaces in the initial threads can make it easy for corrosion to form more quickly, as well as form a nice little bond between said surfaces that can make removing a steel bolt "plug" a lesson in difficulty.

Thanx for all the suggestions, everyone.

 

Heat up an old spade screw driver, push it into the center of the plug. Let cool, twist out.

 

nice

 

Kento, I lost the plug from a new radiator some time ago. I took the radiator to a local Kragen and the guy at the counter let me go through their drawer of plugs (they had dozens) until I found a perfect fit. In your case, if you can extract the remainder of the plug, I suggest taking it to the store and checking.

Also, if one rumor is true and the PWR radiator is the same as the old M2 radiator (the one they sold after they stopped selling the Mazdacomp radiator), then look at this old post for the (Kragen) part number that you need:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/m2-radiator-draincock-160307/

 

I replaced the plastic drain plug as soon as I bought the thing with a steel bolt

plastic and metal threads don't mix

 

my koyo drain plug is leaking...made up of the neck with a rubber/plastic black o-ring with a screw in the center...the screw/o-ring is leaking...gets worse as i tighten need a replacement where?

 

My drain plug froze and snapped the first time I tried to flush my new radiator (the Radiator World POS). I had to drill and tap but I replaced the drain plug with one of these Stainless Steel Swagelok fittings:

I'll never have to use the threads on the radiator again.