NC Aluminum Coolant Expansion Tank for MX5
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Images may differ from actual product appearance.

NC Aluminum Coolant Expansion Tank


PART NUMBER: 61-2037


Reg. Price: $270.00

Sale Price: $213.00

FinishAdd Cap?



Free shipping offers apply only to destinations within US Lower 48.

Reg. Price: $270.00

Sale Price: $213.00

FinishAdd Cap?



Free shipping offers apply only to destinations within US Lower 48.


9/2020 Update: Our Coolant Expansion Tank is now endorsed by Mazda Motorsports as a recommended part of the cooling system upgrades for all Spec MX-5 Race Cars!

Direct replacement for your factory plastic coolant expansion tank. Made in the USA, all aluminum with beautiful TIG welding. Constructed with internal baffles and a machined aluminum neck that takes a factory cap. All of the inlets and outlets are positioned to match up with the factory hoses. The tank mounts to the same location as the factory tank and is built with the same dimensions for an easy fit. Includes view window on the side to check coolant level.

Option is to add a high performance CSF 20psi radiator cap. These tanks are compatible with the factory cap, so replacing the cap is not mandatory, but if you need a replacement for your used factory cap then this is the best option!

NEW optional satin black powdercoated finish offers a more subtle option than the bare aluminum. The satin black is a low-gloss finish that looks right at home in the NC engine bay, unlike a wrinkle or high gloss black that matches nothing around it. Some other examples of powdercoated tanks done by individuals or other shops make the mistake of coating the nipples where hoses and cap attach. That is a no-no! This premium powdercoating is done at the factory the correct way with all critical areas properly masked so that you get a great looking finish without compromises.

Stock plastic tanks are ticking time bombs because as they age they crack and when they crack the coolant pressure is lost and the motor overheats. Unlike the earlier Miata where an overflow leak was not big deal, the NC relies on this tank to be a pressurized part of the cooling system, as soon as a crack forms pressure loss causes the engine to overheat and the motor is usually destroyed. We have NC Generation Miata arriving on flatbed tow trucks every week with blown motors because the owner didn't change the plastic tank until too late. So we decided it was time for a "lifetime" solution. This tank is the solution. It will not fail over time like the factory tank, and looks great as well!

Installation NOTES:
CLAMPS: While the factory squeeze-clamps on the hoses can be re-used, they get weaker the more they are removed/installed and having a tight seal on all the hoses is important since this tank is pressurized. We recommend changing the squeeze clamps out for worm drive hose clamps which can be found at any auto parts store. #4 worm clamp (x2) for the top two nipples, #10 worm clamp (x1) for the bottom.
CAP: You might need to very slightly adjust the 'tangs' on the factory radiator cap to fit the new metal neck with same tension as it did on the factory softer plastic neck, takes a few seconds to do with pair of needle nose pliers.

Great write-up of the install process over on the Revlimiter blog:

YES, there is a view window on the side so you can see coolant level, see it in that window and you are good to go!

Optional satin black powdercoated finish!



Customer Reviews

NC Aluminum Coolant Expansion Tank

My cooling system failed twice, once leaving me stranded on the side of the highway. The first time replacing the cap seemed to fix it. But then shortly afterward the plastic coolant reservoir neck melted right below where the cap screws on. For me the upgrade to an aluminum tank was a no-brainer. I also went ahead and changed the coolant while I was at it.

Installation was straightforward with no problems or surprises. I reused my factory hose clamps, but for some reason my cap just wouldn't fit, so I had to replace it.

In my opinion this purchase is a good investment, even considering the notable price premium over a plastic replacement tank. I don't expect any problems with this tank for the remaining life of the car.

I got this mainly as a preventive maintenance measure. My OEM plastic tank was still fine, but knowing the consequences of a cracking pressurized tank and what it can do to the engine, this is a worthy investment for the car.

Welds on it are very nice, a good quality piece. Not only is it functional, it adds a little bling to the engine bay as well.

Installation is largely straight foward, if re-using the factory hose clamps, the bottom hose (big one) clamp requires wrestling to get it over the new tank's connector tube. It's helpful to have someone help hold the tank while you get it on. Also watch out for coolant dripping out of the smaller hoses as you move them around.

Quick installation! Great insurance to make sure the engine doesn't melt down.

A great product with the black finish. Went in easily and easy to fill. Glad to have the potential for plastic tank failure no longer a possibility.

This is a well constructed piece that is not only functional but beautiful as well. I chose the black one and it looks like it came from the factory when installed. I have 75K on my car and plan to double that by doing prevention like this.

Excellent product - much sturdier than the oem plastic coolant reservoir tank (my oem tank had cracks and chips around the neck). Easy installation. Only issue I had was the holes in the hanger tabs seemed to be slightly off and, of course, no give (perhaps the only advantage of the plastic tank). Holding my mouth just right and wiggling the tank around, I finally got it to go over all three studs. Looks sharp and I fully expect it to long outlast the original plastic tank. Very happy with the purchase.

Nice piece of equipment. Was a fairly straightforward install. Most of the time was spent with the turkey baster tool sucking out the old antifreeze from the original tank. I did pick up some new clamps from the local O'Reilly's parts store. Gave me some more comfort. Used the same hoses as on the stock tank.

The fit and finish on this part is great and very easy to install. Looks very good under the hood.

I no longer have to worry about the flaws of the OEM tank. It is much easier to verify the level of coolant with the viewer on the side.

This is a peace of mind device. Extremely well-done welding. Car only has 23,000 miles, even with a cross North American jaunt. To be honest, the plastic tank did not appear to be at all deteriorated, but I'm sure it happens . Thanks Good-Win and Moroso!

Super easy install of a nice product. It really compliments my black engine compartment.


Fit like a glove. The tank was a very easy install and really is a great design. I have no complaints about the quality of the product. It really is an eye catcher when the hood is up.

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