I've been waiting to do this for quite some time, but didn't have the time to sit down and write this. But I finally did it. So here goes

Alright so most of us have been there. You try to remove the fans, or a coolant hose, or anything around the radiator. That means you have to drop the whole radiator, and that means disconnecting the top radiator hose that goes to the coolant tank. As soon as you even TRY to remove it, it breaks! I know most of you are gonna say "oh that's because you try to pull it like an ape. You gotta be gentle with it". Yeah, no. If your radiator is a few years old, no matter how gently you try to take it off, it's gonna break, and when it breaks, because that part is plastic, the only way to fix it is to buy a new radiator. That's not cheap.

So I thought, why spend hundreds on a new radiator, when it's just a TINY hose that broke off. Why ditch the whole radiator for this?

Luckily, a friend of mine and I have found a solution that can permanently fix the nipple. The idea is, once the plastic nipple breaks, you fix another nipple to it, made out of nylon plastic. Way stronger than the plastic on the radiator tanks. You just need to make the new nipple to the size of the original nipple, and screw it in, apply gum, and away you go. It's that simple! I know you guys are gonna say "oh it's not gonna hold. The pressure is too high". Trust me. It's gonna hold. But you gotta do it right.

Here are the steps.

1. You need to take the radiator AND the broken pieces of the nipple to a lathe machine shop. Make sure to take the pieces, because they're gonna need it to determine the size. Tell them you want a nipple made to the exact same size as the nipple you just broke. Show them the radiator and the broken parts. It should give them a good idea of the size. The material my guy chose was plastic nylon. I've attached a picture. The guy took one of those and cut it to the right size. They've done over a 100 radiators and none have failed.
2. Shave off the remaining plastic parts of the radiator nipple, making it flush with the surface of the tank.
3. Make the nipple. You're custom making a part. You can design it however you like. The one I made had a slightly thicker edge, to stop the hose from coming off. The bottom part of the nipple that goes into the radiator tank, has a screw in-type design to it (See pictures, I've circled what i'm talking about), so we could literally "screw it in". We got the thickness perfectly matched with the hole in the radiator tank, so it fights tight, but not too tight to break off the rest of the radiator 😂 make sure to screw it in and test to see if it's tight enough.
4. You need a special gum called "Araldite". I've attached a picture of it. It has two tubes. You put couple of drops from both to a small plate, mix them up and apply. Apply on both the nipple you just made and the radiator hole.
5. Screw it in. All the way. Until it fits tight and has no play.
6. Apply more Araldite to the edges of the nipple. Creating a "seal" between the surface of the radiator and the nipple you made.
7. Wait for at least 4 hours. The longer the better actually.
8. Install it back into the car. Watch for leaks.

If you did everything right, you should have no leaks. We've done this to a few RX-8s and all of them are still perfect.

The cost for me, was actually around $2. But labor is really cheap where I live. I'm assuming it shouldn't be more than $20 in America.

Hopefully the next time you guys do anything radiator related and it breaks, you won't have to buy a new one

Let me know what you guys think.

Thank you

 

You like playing Russian Roulette too?

Fixing a plastic radiator tank is basically the same thing.

Radiators are a couple hundred bucks...overheat a rotary ONE bad and you are spending 3-4K to fix it minimum

I don't get it ;(

 

Have you tried doing this? Trust me, it's stronger than you think. It's WAY stronger than the stock nipple. If you pull on this, the whole top tank will crack. Not this.

3-4K minimum for a catastrophic overheat. I think we've established that a minor overheat won't screw up the engine. That whole theory turned out to be a myth. This is the tiny little horse that runs from the coolant bottle to the top radiator tank. Even if it breaks, it's not gonna spill a lotta coolant. Yeah there's pressure loss and yeah it'll overheat, but not a lot. It happened to a few cars over here. They swapped radiators and broke the nipple while fitting the hose on. Didn't know they were broken until the cars overheated. We fixed them with these nylon nipples, and a year later the engines are still fine, and these nipples are holding up well. We check for leaks daily. No leaks. No coolant loss.

The whole point of this is to fix it with the least amount of money. At least until one can afford a new radiator. This mod will get the car back on the road.

So far, there's been a 100% success rate. But yeah, it really depends on who does the job and how well it's done.

 

The least amount of money for how long? That little nipple if it blows will empty your whole cooling system before there will be much notice.....that WILL lead to a catastrophic overheat unless you get really lucky

So your $20 fix is $150 less than a new radiator.....

Usually the nipple breaks because the end tanks are getting brittle. So fixing a brittle end tank is asking for it long term

I stand by my opinion and caution doing this for anything but a very short term fix.

I'm all for trying to save money...but some systems like the brakes, fuel and cooling system are not the place to try and save a buck

 

It depends on how long you wanna keep it that way. My friends are still running with these nipples. No problems.

I made this thread to help people who can't afford to buy new radiators right away. To help get their cars back on the road. To buy them a little more time. If they feel insecure about this, they can opt to ignore this. But if they want to, it can be fixed for $20. There is that option. That is what I wanted to share.

We had 4 cars that had the coolant nipple break while driving. All of them lost a bit of coolant, but they didn't lose ALL of their coolant. Yeah they overheated, but nothing happened. The end tanks are made of a thicker plastic than the nipple. They're stronger than the nipple. The stock nipple is so fragile. Applying pressure on them would make them crack. These nylon nipples are hard as metal. You gotta see it for yourself man. You're lucky you can get a new radiator for $200. Where I live a new radiator for an RX-8 is over $800. And the actual cost for my buddies to do this mod was $2. So it was $798 less.

Yes there's a risk. Everything has a risk. But it's not as bad as you think. Even I wouldn't have believed this. But now that I've seen it, I know that it works. If it's done right, it won't leak, and it should extend the life of the radiator by at least another year. The guy who fixed our radiators have fixed over a 100 radiators from different models. Some were broken when they came from Japan. All of them were fixed with these nylon nipples and all of them are still running great. It's that solid.

 

I'll take your word for it that it works.
Only here in the states a pro machine shop would probably charge more than $20.
I could be wrong, Idk for sure.

 

Haha my bad. I don't know the exact prices in America. It doesn't take a pro to do this though. Don't you guys have lathe machine shops here and there?

All they gotta do is make a copy of the nipple that broke off, with a screw in design at the bottom so it "screws" into the top radiator tank. Pretty simple.

 

Machine time here...if you can find someone that has time to do a small job like this is $100 an hour or more. They usually won't do anything for billing less than an hour

You can buy brass NPT to hose nipples that would work in similar ways....for about $4..and they will likely bond in as well as the poly ones...as the epoxy doesn't stick well to it either

Still a gamble....but each to his own I guess