Hello everyone,

I recently installed my Koyo radiator in my 2006 xB. Everythink fit perfect. I am only having 1 issue now. I have a small leak I beleive to be coming from the passenger side drain plug. The radiator has (2) drain plugs from what I can see. Probably to hook up an inlet pressure hose and outlet relief hose to flush the system.

Now, the radiator only came with (1) drain plug on the driver side. The passenger side drain plug was taken off of my factory radiator and installed onto the Koyo unit. I suspect that this is where the leak is. I am only getting a couple of drops here and there. I noticed when I installed the passenger plug that it didn't seem very "snug", but decided to use it anyways. I checked all of the hose clamps and hoses and I am not getting any leakage from there.

Have any of you had this same issue? If so, what did you do to correct it?

The only think I can think of is to get some water resistant silcon and spread some on the drain plug to prevent the leak.

 

Are you missing an O ring or something? Why did your radiator not come with the plug?

 

i just went thru all this personally...ok so the koyo comes with 2 lower openings one on the driver side that comes with a plastic petcock & the second is in the OE location without a petcock. now you would think you could just use the one from the old radiator...wrong!....the oe drain hole has a small ring surface that the o-ring on the petcock seals with, the koyo in all it beauty and quallity lack this surface and slowly leaks coolant. i had to buy a slightly larger petcock, tap out the drain a lil

 

No, not missing an o ring. I checked the Koyo box again and it seems that their radiator only comes with (1) of the (2) drain plugs. Again, I had to use the passenger side factory plug to use on the Koyo. This has an O Ring, but it doesn't fit "snug" It is a nylon piece and it seems that the threads just don't seem to bond well with the aluminum.

I drained the radiator again tonight, bought some water resistant RTV silicon and it seems to be fine now. Again, It was only causing a sliight drip after the car was shut off. Everthing seems to be ok now.

I would just suggest doing the RTV if you are getting a Koyo Radiator.

 

also used teflon tape for good seal no problems after either oh and the second lower drain is actually for a temp sensor for aftermarket temp gauge....any other help i can be let me know

 

Nice, so the driver side port if for an aftermarket gauge, correct?

I have noticed that the fan doesn't seem to kick on as much now with the Koyo, so I have to assume that it is cooling better already. I can't wait to see how well it does with the turbo.

 

i think you missunderstood me i know it wasnt missing an oring the petcock has one one it.....if you look into your old radiator there is a plastic ring type surface that the o ring matts against to form the seal.....the koyo doesnt have this i did side by side comparisons and yes the plastic petcock is too small for the koyo because it doesnt have the "extra" ring surface inside for the oring to hold it/seal with....i hope the rtv works for you i tried it all and wound up havin to retap and go with a larger brass petcock tef-taped

 

I understand you now. Thanks!

It looks as if the RTV Silicon worked.

 

i had the exact same problem and i also discovered that the style of plug is completely different between stock and koyo. as deviousxa said, the stock seal uses and o-ring mated to a cylinder on the inside of the radiator. the koyo seal should be with a flat rubber washer on the outside similar to the driver's side plug that they provide.

i contacted the company who sold it to me, but they never wrote back. koyo is in singapore. how awesome is that.

i bought a sealant that was waterPROOF not merely resistant and also capable of withstanding high temperatures. i can locate the brand and product name if somebody wants.

after leaking coolant all over me and the floor, i drained it completely, dried out the passenger's side hole, applied the sealant, installed the plug, and waited a few hours before refilling. the sealant needs an hour to set and twenty-four to cure completely. i would have waited 24, but i had to go somewhere the next day.

i wish that i had known about this before the instal.

 

i found that it does leak a little still. i can only tell by touching the bottom of the plug with my finger.

 

How about some pics, and where did you guys get your Koyo's?

 

there is not much to see once it is installed. i think that somebody else already posted
pictures in another thread.

some fleabay seller

 

yea

 

Just installed a Koyo radiator in my xA.

Got it from eracingzone.com. $210 + tax and shipping.

I used the OEM plug on the lower radiater hole on the passenger side.

I found an o-ring out in the garage and used that on the plug. No teflon tape, no RTV sealant.

I'm going to test first with some distilled water, but the real test will be when the radiator is at full temp with coolant.

I'll post the results.

-Pete

 

I could be mistaken but, That "extra drain hole" is where you are supposed to install your water temp sensor for your aftermarket guage.

 

I'm still trying to figure out why a new radiator would be needed. It's not gonna cool better enough to warrant the added cost.

 

THREAD JACKING!

bB2NER, unless you go FI or high compression, i would not bother with the radiator unless it was for shows.
when the heat starts zapping your power in the summer, you will grab every bit of cooling that you can get.

 

Especially if you are turbocharged and live in Arizona!

 

Guess I've been schooled. I had no idea the stock rad wasn't up to the task while being turbo'd or compressed. After this summer it felt like Arizona in TN but I never had any overheating problems.

 

I think I watched 3 Japanese tuner shows where they turboed or supercharged a Vitz 1.5L and they all had cooling issues.

Stock, it's probably not worth it.