Okay, it looks like my radiator has finally sprung a leak so it's time to upgrade. I know I'm going to be getting a Koyo Radiator (the all aluminium one). I've got a set of Samco Hoses on order, but need to see what kind of radiator cap I should run with this new setup.

From what I came across on one of the websites it seemed like the stock radiator cap doesn't work with the upgraded Koyo radiators. Is that true?

Are there certain brands that are good to get or any that should be avoided?

I was looking at potentially getting the Arc Radiator Cap. They seem to be good quality from what I've seen. Can anyone give any opinions on these one way or another?

http://www.maperformance.com/arc-1.3...ti-amc001.html

I also thought about getting the Koyo Radiator Cap.

http://www.advancespeedshop.com/koyo...13-p-2500.html

Problem with that one though comes with this statement.

"NOTE: USE W/ KOYO OE REPLACEMENT RADIATORS W/ MICRO CAP FILLER NECK"

Isn't that the Koyo radiator that has the plastic endtanks? It seems like that particular cap doesn't work with the all aluminum Koyo radiator (or does it?).

I also came across the Mishimoto Temperature Gauge Radiator Cap.

http://www.maperformance.com/mishimo...ll-import.html

That seems kind of cool, but from reviews of it there seems to have been people that have leaking ones of those (so I'll probably end up avoiding that particular one as well as the other Mishimoto brand Radiator Caps).

Are there any other recommendations?

I know I'll need fluid (how much should I get for this thing and should I stick with Subaru OEM or should I switch to something else)?

Also, is there anything else I should also be looking at getting since I am upgrading the radiator?

 

The stock radiator caps will work with the koyorad. I had a koyo myself on my other car, loved it. I used the stock caps and they worked just fine.

You will want to get 2 gallons of coolent to fill this bad boy. I run the prestone 50/50 premixed stuff just to make it easier on myself. otherwise get a gallon of coolend and a gallon of distilled water and mix yourself.

 

Ya stock cap on my Koyo as well.