[RESOLVED] How to Empty a Koyo Radiator

[snowborder714]

I have a Koyo radiator insalled and lately have been needing to drain some or all of the coolant out. The stock radiator was fairly easy to empty, but this one doesn't have a drain tube on it. The past two times coolant has been shot over halfway back the underside of the car. I was wondering what you did to empty your Koyo easily.

My brother was thinking about getting something else to thread in there that would allow easier drainage but have no idea what could put used.

Here is a picture of the drainage system. The black knob is just a threaded plug.

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[blcknspo0ln]

I just put a towel over the draincock and open it full blast. Hold the rag in place over the drain into a bucket. I could imagine if you found if it's NPT, you could get a check valve with a 90* fitting in there.

 

[steve]

I didn't have time when I put mine on but I was going to take the black plug to the store and get a drain petcock in matching threads to replace it.

 

[snowborder714]

What store would carry drain petcocks? Hardware? Auto?

That sounds like a good idea.

blcknspooln - That's a good idea and will help me out as I have to possibly change a coolant temperature sensor soon!

 

[turboglenn]

We have the same issue with after market radiators on some of the porsche club 944/968 race cars, because it sends the coolant flying all over stuff it shoudln't be on.. Instead of using the drain hole, we usually loosen the lower rad hose clamp. Pull the hose back just a bit and stick a flathead screwdriver between the hose and rad outlet. The coolant will use the screwdriver to flow off of and you can aim it right down into your drain pan. It may sound ghetto but it works and none of our car owners ever complain about us doing it that way.

 

[snowborder714]

I called Koyo the other day and found out the thread size is M10 x 1.25. I have been looking around for petcocks, but haven't really come up with much. There are a few on eBay which are made for motorcycle fuel tanks, but would require an adapter as they aren't metric.

Anyone else have any ideas? I'd like to get something that faces downwards, which means it'd have to have a 90* bend in it. If not, something with an opening on the end where I could attach a hose would be ok.

 

[Kevin Jewer]

I'm pretty sure I've seen metric petcocks around somewhere, but I can't recall where. Alternatively, if you're into the fancy fittings you could run a metric PT oring fitting to NPT adapter into an earls ball valve, cost about 40 bucks and be pretty sweet. Could even use a short line or an elbow to direct it downward into the catch pan. Overkill of course though.

Looking for metric parallel thread to NPT adpaters it looks like they all go to 1/8th pipe. M10 is probably a good size to drill out and tap for 1/4NPT anyway, then run a Be Cool 72025 from summit for 10 bucks and ship it.

 

[snowborder714]

Alternatively, if you're into the fancy fittings you could run a metric PT oring fitting to NPT adapter into an earls ball valve, cost about 40 bucks and be pretty sweet.

Any links to this stuff? I seem to be having trouble finding the PT oring fitting and the ball valve.

And I'm open to any suggestions, even if you think it's overkill. I like doing things right the first time as well as neat and stealthy. So if it costs more, but look/functions a bit better, I'd consider it.

Also, thanks for the suggestion on the Be Cool petcock. I'll definitely keep that in mind!

 

[Kevin Jewer]

The valve is an Earls part, at summit you'll find it under departments>plumbing>valves check/shutoff>shutoff valves. Yes it's scary that I know that by memory. It's about 35 bucks. Problem is that it has a female 3/8th NPT inlet IIRC, so you need at least one adapter, probably two. A M10x1.25 to male 3/8th NPT would be ideal (fewer joints, shorter length, lower cost), but I'm unable to find one in a quick 5 minute search. It should only be about 5 bucks, so the overall cost is still pretty low at about 40 bucks. If you need to use two fittings to make the transition it's not as cool but it will get the job done. Ge fancy with a short piece of AN line with 1 fitting to fit the valve's output and you've got a nice clean setup.

You could also check Mcmaster.com for a coolant safe quarter turn vave with a male NPT input, and use a cheaper NPT fitting to rubber hose on the outlet to achieve the same effect for less money (but additional keyboard time to piece it together).

For the be cool petcock option all you would need is a standard 1/4"-18 tap like Mcmaster.com PN 2525A113 for ~6$ and a common 7/16th drill bit. It would come in under 20 bucks but would still provide a sloppy process.

 

[snowborder714]

Thanks for all of that! Dang, you were dead on with the valve...that is kinda scary.

I will have to look into all the different options tomorrow. I agree that less adapters would be better (none would be ideal, but I don't see that happening without some work on the radiator). There are 3/8" and 1/2" fittings on there. The problem is I don't seem to find any M10 x 1.25 adapters. I've seen some M10 x 1.0, but none in the 1.25 variety. I may have to give McMaster or my local hose shop up and ask if they have them.

With those Earls fittings, I could either get one with an AN outlet or a female NPT outlet. Hmm...they both could work (especially since I have some spare -8 hose laying around. But with the NPT I could probably hook up a 90* fitting or hose barb temporarily just for emptying. More stuff to think about tomorrow.

 

[turbosax2]

I'm snowborder714's brother. We've spent over 2 hours on the internet and called over a dozen places, and nobody has M10 x 1.25 adapters. Does anyone know where to source this part or have the tools to make one?

If we can't find that adapter, we're looking at using a metric-AN adapter then a AN-NPT adapter. This is getting a bit more expensive than we originally thought though.

Or the last option is cutting the bung off and welding a new one on.

 

[Kevin Jewer]

Did you guys check to see if a 1/4 NPT fitting is close enough or bigger than a M10 to just tap it out to pipe threads? If my garage wasn't 45 minutes away I could check it out for you. Ideally the bung would be big enough to tap right to 3/8ths so you can use a 3/8ths close nipple to adapt the valve to the radiator with one piece, but those taps are less common and more money and the drill is probably an odd size. A local welding/fabrication or machine shop could probably do it for you for 10 bucks though.

 

[snowborder714]

No, I haven't checked yet. The car is 45 min. away from me (at home) right now and the radiator is still in the car. The only way to really compare the M10 to the 3/8" is to hold a bung up to it. I'm not sure how accurate that would be. But I'll have to look into that. If not, I have an aluminum 3/8" bung that I could have welded in place of the one that's there if need be.

 

[SleeperG]

have you been to an air/hydraulic supply store?

I go to a place called Parker. thats where i've built all my fuel lines, oil cooler lines..... every line. they have dozens of different hoses from stainless steel, braided kevlar reinforced. all for dramatically less than you will find online, even from summit. without shipping costs.

they also have thousands of hyrdraulic fittings and apperatus on hand, and can order just about anything you can imagine.

I've seen petcocks and draincocks with my own eyes in their store.

my suggestion:
see if there is a Parker Store in your area.

 

[snowborder714]

Sorry, no Parker store in my area. You have no idea how many hose and fitting specialist places I called today. No one carried them, and if they did, they were in the M10 x 1.0 size.

 

[SleeperG]

and they don't have acces to a bushing style adaptor that could get you from one thread to the other.... without protruding out 2 inches?

 

[snowborder714]

Nope, the only suggestions they had was to weld another fitting in it's place.

Would you mind contacting your local Parker and see if they'd have anything I could use? I'm looking for a metric to NPT adapter from a male M10 x 1.25 to a male 3/8".

I may look into either drilling and tapping or just get a new bung welded though because I just don't think they make that type of adapter.

 

[awdwhip]

Hey snowboarder, how has that Koyo treated you so far? Have you noticed reduced collant temps? Lemme know, I cant seem to make up my mind on which radiator to buy.

 

[snowborder714]

Well, for the few times I've ran it since it was installed, my temps have been solid around 176. This is running a 50/50 mixture with no additives. I haven't been able to run it for an extended period of time (like a few weeks) to see how it's been. Plus, it's been really cold here. I think it'll do just fine once it warms up and I switch to a 30/70 mixture with a bottle or two of Water Wetter. But only logging will tell what happens. It's thicker than the other cores out there and I was able to mount my Flex-a-lite slim line fans up pretty easily so that's a plus.

And it looks so much better than the stock one!

 

[snowborder714]

The solution has been found!!

I needed some adapter to go from the threaded hole in the radiator to a ball valve, as this was the best option. So I talked to Jeff at ssstuds.com and he made an adapter for me that fit great! It went from M10x1.25 (goes into the radiator) to 1/4" NPT (for the ball valve). It is 1.374" overall in length. The M10x1.25 threaded section is .450" long. The 1/4" NPT threaded section is .553" overall. Here is a picture of the adapter.

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And the ball valve with the adapter.

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Here it is installed and in use. I put a 1/4" NPT male nipple on the end and happened to have a prebent piece of hose lying around which worked perfectly.

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I decided to take the handle off of the ball valve so that it wouldn't accidentally open. I can now just take a wrench and move the nut that is on there (originally used to hold the handle on) to open and shut the ball valve.

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And just to be safe, I put a plug in the end so that in the freak accident that the ball valve opens, coolant won't go flying everywhere.

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I tested it and it's very easy to use. It opens and shuts easily and you can control the flow without a problem. It does flow very well too so you won't be sitting there forever waiting for the system to empty.

Hopefully this helps other people in the same situation. The adapter didn't take Jeff too long to make and cost me $20. I'm sure he'd be more than willing to make them for others.

 

[Defiant]

Good lord, how often do you drain your radiator? When there's no drain installed, the usual method is to just yank the lower hose.

 

[RipperXX]

I want something like just a damn bolt, that stupid F*cking nylon plug and o-ring is the underline cause of my blown HG