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Buy Coolant Expansion Tank and Radiator Overflow Bottles

After a few years of driving, your BMW or Mini’s Coolant Expansion Tank will begin to develop small cracks. These cracks allow air bubbles to enter the system and cause the cooling system to lose pressure. When this happens, it’s important to have your cooling system inspected by an expert and replaced if necessary.

Genuine BMW + Mini

Genuine BMW + Mini, which makes parts for a variety of vehicles, offers a number of radiator and coolant expansion bottles that you can use to protect your car’s engine. These include the following:

  • Genuine BMW Expansion Tank with Cap and Grommet Kit (part #83-21-9-593-156)
  • Genuine Mini Cooper Expansion Tank 1.6L/1.8L (part# 8321 959 740)

BMW 7 Series Radiator Overflow Bottles

The coolant expansion tank is a reservoir for the radiator coolant using Radiator Overflow Bottles. It’s located at the bottom of your engine bay, and it holds excess coolant that can be used to refill the system when needed. The radiator overflow bottle is mounted on top of this reservoir and allows air bubbles that collect in the system to escape without overfilling it.

Coolant Expansion TankCoolant expansion tanks come in many sizes and shapes, but they’re all designed with similar components: a metal shell with mounting hardware installed on one end, an opening on another end (to refill), and a cap that screws onto this opening to keep dust out when you’re not using it. They also have BMW part numbers printed on them for identification purposes—this one is #60225051243-1 (for reference).

5 Series

This is a list of BMWs that use the 5 Series. The list includes models from the E39, E60/E61, F10/F11, G30/G31 and X5 (E53) series.

3 Series

Coolant Expansion Tanks and Radiator Overflow Bottles

Coolant Expansion Tank and Radiator Overflow Bottles (13)

Coolant Expansion Tank and Radiator Overflow Bottles. Genuine BMW + Mini

7 Series – E38 (1995-2001), E39 (1997-2003), E65/E66/E67/E68 (2002-2008) / 740Li, 750Li, 760Li, 728i, 730i, 740iLXI X3 – E83 (2003-2006), X5 – e53 (2000-2006). 5 Series – e34/e39 528/528i 530 sedan 540 sedan 550 sedan M5 6 Series (e24 633CSi) Z8

X Series – E53, E70, E71, F25

  • BMW X5 (E53)
  • BMW X5 (E70)
  • BMW X5 (E71)
  • BMW X5 (F25)
  • BMW X3 (E83)
  • BMW X3 (F25

Z Series – E85, E89

  • BMW Z4 Roadster E85, E89 (Z4M)
  • BMW Z4 Coupe E85, E89 (Z4M)
  • BMW Z4 M Coupe E85, E89

Mini Cooper/Cooper S (R50/R52/R53/R55/R56)

The expansion tank is located in the engine compartment and is usually mounted on the radiator or intercooler. When it comes time to replace your cooling system, you should replace this as well. If you’ve already changed out your coolant system and are experiencing problems related to overheating (such as a leak from somewhere in the cooling system), then this may be your issue.

Coolant Expansion Tank and Radiator Overflow Bottles

A coolant expansion tank is a plastic or metal reservoir that’s installed on the engine. It stores coolant to help maintain proper system pressure, but when the cooling system reaches its capacity and there is no more room in the radiator, coolant overflows into this bottle. The overflow tube runs from the top of your radiator down through your upper engine shroud to an opening near your front bumper where it terminates at a location below ground level (usually within inches). When you park your car and shut off its engine, this excess fluid drains out of this tube when gravity pulls it downward toward earth. As long as both ends are sealed properly, there should be no leaks with either type of overflow replacement bottles for driver side applications—they’re made with rubber seals at both ends so that they can hold water indefinitely without leaking out through their openings until gravity pulls them down after being parked overnight.

When refilling these units: Be sure that all connections are tight before turning on any water supply devices such as faucets/sprayers etc., because if not done correctly could cause damage due to leaks inside housing cover itself causing corrosion which could lead to cracks over time causing larger problem such as burst pipes during winter months when temperatures drop drastically causing extreme pressure build up inside home’s plumbing lines leading them too rupture!

Promptly empty the bottle.

The first step to preventing an overflow is promptly emptying the bottle. If it’s full, it can and will overflow, so keep a watchful eye on how much coolant you have and make sure that you top it off when necessary.

If the bottle becomes blocked, this could also cause an overflow of fluid. If there are any blockages in the system—like leaves or other debris—this can lead to overheating of your vehicle and internal engine damage.

Finally, if you don’t empty your reserve tank regularly (or at all), this could cause corrosion inside of it due to constant exposure to coolant chemicals over time which can lead to corrosion buildup within both plastic bottles as well as aluminum-based tanks like ours here on CoolH20Shop!

Coolant Tank for Other Cars

When it comes to cars, there are a lot of things you need to worry about. You have to make sure your tires are inflated and your oil is changed regularly. You need to keep an eye on your transmission fluid and brake fluid levels. But what about the coolant that keeps your engine from overheating?

That’s where we come in. We have a wide range of coolant expansion tanks and radiator overflow bottles to fit Ford and Nissan vehicles as well as Ford cars. All of our products are built with high-quality materials like brass and aluminum, so they can withstand the demands of everyday use without leaking or breaking down before their time.

Whether you’re looking for a replacement part or want to upgrade your current setup with something new and improved, we’ve got the right product for you!


We hope this article has been helpful in deciding which coolant expansion tank and radiator overflow bottles are right for your car, truck or SUV. If you have any questions or comments, please let us know!

Milton Neil
Milton Neil
"I'm Milton Neil, and I love analyzing data so much, I dream about pivot tables at night! You could say I'm the Sherlock Holmes of spreadsheets - always on the hunt for clues hidden in the numbers. I like to think outside the box, or should I say, outside the cells. I'm not afraid to take risks and create innovative solutions to problems, even if they're not exactly conventional. Some might call me a rebel, but I prefer the term ""spreadsheet maverick."" But don't be fooled, I'm not all about work and no play. I love to unwind with a good game of Excel-erate or a pun-tastic joke. In fact, I'm the go-to guy for all your spreadsheet humor needs. So if you need a laugh or a killer data analysis, I'm your man!"