mini love - part 20

How much can you spend on the coolant expansion tank on the Mini? Can be a lot and you don't get any more benefit than if you spent wisely.

Like many European cars the coolant expansion tank in the Mini is made of plastic. They actually work quite well, up to the time when they fail catastrophically. The one in my Mini is original and is still functional after 13 years. The one in my VW Westfalia Vanagon camper failed at 70,000 miles after 26 years. To me they are actually not that bad but I live in the very temperate Pacific Northwest. When the one in the Vanagon failed, I decided to go with a no name and not OEM brand. I figured that might give me a better odds that the welded seam may be constructed better over the ones from OEM manufacturers (a blind leading blind phenomena).

the 13 year old plastic coolant expansion tank in the Mini

As the failure of the expansion tank is a very unpleasant experience on the road I decided to purchase a replacement ahead of time. The first question is which one. There are a lot of choices ranging from the way overpriced genuine MINI, equivalent OEM, aftermarket manufacturers that replicate the similar plastic tanks, and a wide array of aluminum tanks. The last category cost widely depends where you get them. Most are presented as superior parts but the reality may be quite different.

this is one of the most expensive one and the weld appears to be very poor; the rim of the collar also is too thin compared to the factory plastic tank

it is Forge brand, not forged

here are the typical offerings on eBay

I shopped around on the web and found the lowest price one that comes with a billet aluminum machined cap. I cannot tell if the cap has built in pressure relief mechanism. Since I am suspicious of the design and quality of the pressure relief cap I set out not to trust any cap that is included with the aluminum tank. Most of these tanks appear to be manufactured from a common design or copy of the design. I was counting on the one that I chose would have the collar and thread cut to be compatible with the plastic factory cap. Except a few tanks that are sold without the metal cap, I cannot find any that tell me I can use the factory cap with the tank. The tanks that are sold without the metal cap typically cost twice as much or higher. From what I observe most tanks that shipped with the cap is more likely than not, compatible with the factory cap. I decided to take a chance if I can find a tank with significant saving. Found one I did, and it was shipped from California, with the cheapest price you can find on eBay.

today it arrived

I examined the welds and they are excellent as is the overall quality

the billet machined aluminum cap threads smoothly with the tank collar too but the cap has no provision for over pressure relieve; I was expecting this so is the tank collar compatible to the factory cap?

It is really hot out today and the Mini is under a car cover to protect it from UV. It was a bit of work to open the bonnet to check. It turned out my hunch is correct. I can reuse the Mini factory cap with this new tank. As I don't plan to swap in the tank soon, I cannot verify the three mounting points mate perfectly. I did performed a rough check of the two hose fittings and I see no reason I should be worry.

strategic Mini parking to avoid mishap by the careless

Mini and Porsche

at Alta Performance

Mini and 718 Spyder

GT350 with a flat plane crank V8

this R8 has manual gearbox - quite rare and I didn't even think it is an option