For Mini owners, checking and replacement the serpentine belt is part of routine maintenance. The belt is driven off of the crankshaft and turns accessories such as the water pump, supercharger/water pump, alternator, and air conditioning compressor – depending on your model. The belt should be checked regularly, so it’s a good idea to do whenever you change your oil.
You’re looking for cracks when you inspect the belt. They usually appear on the inside of the belt and if you see any you should replace the belt right away.
With the poly-ribbed belt that Minis use, replacement is pretty simple. The tension that holds the belt tight can be released using a specialized tool. The tensioners rotate in different directions on both the Cooper and the Cooper S, so you will have to rotate based on your car.
To start, remove the fuel tank vent valve – it is set above the tensioner on all models. There is also an electrical plug underneath that should be removed. Once you have that off, you will need to remove the inner fender liner on the passenger side. Use a Phillips head screwdriver to remove the screws and tabs holding it in place. Once that has been removed you will have a clear view of the belt.
Use your serpentine belt tool to rotate the tensioner and release the tension on the belt. If you’re not sure which direction the rotation needs to go try one, you will know right away if it is reducing the tension or not. There are two small holes on the arm that will become visible once it is collapsed. Stick the pin through the second hole once you see it.
One you have it pinned, you can remove the loosened belt. It runs through pulleys and it’s best to take note (or better yet a photo) of the setup before removing it. If you know the belt is bad, you can save time by simply cutting it out rather than working it off the pulleys, though by working it off, it will make it easier to replace the new one.
The process for both the Mini Cooper and the Mini Cooper S is pretty much the same. Once you have the belt off, examine it for cracks or other signs or wear or damage. If it looks good you can simply reinstall it, if you spot issues, or you’re not sure, it’s best to replace it to avoid further complications.
If you bring you Mini to Bimmex, either in Woodbridge or Markham, we will do this inspection for you each time we change your oil. If your belt needs to be replaced, we will do the installation as well. If you prefer to do this kind of maintenance on your own, we can walk you through the installation process in the next article.