R56 MINI Cooper Coolant Pump Replacement

I recently had a look under the car and noticed that my coolant levels were dropping slowly.  While it wasn’t a major leak, I was losing enough coolant to require a small top-off every couple of days. I finally got under the car and noticed that I was losing coolant from the coolant/water pump located on the passenger side of the car.

The pump is located near the passenger side wheel well, same place you’d find the crank pulley. The pump is not directly driven from the crank pulley and is engaged using an idler pulley as needed. Because of this, the repair does not require you to remove the belt from the engine.

This is a 3.5 ~ 4 hour job for someone doing this repair for the first time. You’re looking at about $600 if you have a MINI dealership do the repair.

A broad overview of what this job will require is as follows:

  1. Remove passenger headlight and black engine bay bar.
  2. Remove engine block mounting hardware and rest the block on the car’s body.
  3. Remove the wheel well cover.
  4. Remove pulley and old coolant pump.
  5. Replace pump and reassemble in reverse order.

Sounds easy, right? Well, let’s get started!

For this job you’ll need:

  1. 10mm combination ratchet wrench with 10mm wrench socket. See here and here for examples. This tool is essential! It’s impossible to do this without a thin 10mm wrench!
  2. 10mm socket with ratchet (1/4″ or 3/8″ driver will work, although the 1/4″ will use a smaller socket wrench)
  3. Socket extensions (as needed)
  4. 13mm and 18mm socket with wrench. You might also need a breaker bar for the 18mm socket.
  5. T30 driver
  6. 10 ~ 15mm box end wrench. Doesn’t matter, just as long as it fits around a bolt
  7. Pry Bar
  8. Jack
  9. 2 x Jack stands (only if you aren’t on a lift)
  10. Phillips and standard screwdriver
  11. Knife or large standard screwdriver
  12. A replacement coolant pump (~$180)
  13. Bucket to catch coolant
  14. Brake cleaner
  15. Some rags you’re willing to throw away
  16. A 2nd person that knows how to use a floor jack
  17. Muscles


  1. Impact driver with 3/8″ or 1/2″ driver attachment
  2. Hose clamp tool
  3. 4 point lift

Now that you’ve gathered all your tools, let’s get started!

  1. First thing you have to do is remove the black bar that goes around your engine compartment. You should need to remove 4 x 13mm bolts, 4 x T30 bolts, and a couple (3, I think) 10mm bolts.
  2. Remove the black tube next to the vacuum line on the top right (nearest the passenger side door) of the engine. It should be a 4~5 inch tube with a hose clamp on one end and a clip on the other. Remove the tube by pulling out the clip.
  3. You should also completely remove the passenger side headlight. Try to mark where it originally was to avoid having to re-adjust it later. Removing the driver side light isn’t necessary, but it helps to loosen all the bolts.[singlepic id=783 w=320 h=240 mode= float=]
  4. Your car should now be on jack stands or, supported by the lift if available. DO NOT WORK ON A CAR SUPPORTED ONLY BY JACKS!! THIS IS DUMB AND SHOULD NEVER BE DONE!!
  5. Get under the front of the car and place a bucket under the hose which runs across the underside radiator. This hose should have a clamp or two which, using either pliers or a hose clamp tool, should be removed in order to drain all the coolant from the radiator and part of the system. This will make sure less of a mess is made when removing the pump.
  6. While the coolant drains, remove the front passenger wheel and set it aside. Also, place a set of towels in each end of the coolant tubes to keep from spilling more coolant on the ground.
  7. Place a jack under the car and gently support the oil pan (not the transmission fluid pan).
  8. Use the 13mm and 18mm sockets to remove the engine mount support. Remove the 18mm nut first, then work on the 13mm bolts. Don’t forget to remove the nut/bolt connecting the mounting bracket to the grounding cable (braided cable with a flange at the end). The bolt is unsupported, so make sure you don’t lose it!
  9. Using the thin 10mm wrench, remove a 10mm bolt located below the bracket you just removed. It should be holding a wiring harness located along the back edge of the engine block. It’s very important that this bolt be removed because if not, you may damage the wires!
  10. Once that piece is removed, the engine should now be supported only by the jack. SLOWLY lower the engine block until it’s supported by the frame. Don’t worry, it’s okay to do this!
  11. Congrats, you’re 1/4 of the way done!

Break time #1! The fun has yet to come! Go drink a beer and come back happier, and a bit less sober!

  1. Ok, next we need to remove the felt lining covering the inside of the wheel well. It should be held onto the frame of the car by plastic supports and two T30 bolts. The bolts are located at the top of the wheel well. Don’t forget the plastic support directly above the wheel well! Mine was damaged, so I had to cut it off. One more, one less, who cares, right?
  2. Once the lining is removed, you should have a clear view of the side of the engine. The pulley you have to remove is shown on the top left of the following image. It’s the gray pulley with silver bolts.[singlepic id=784 w=320 h=240 float=]
  3. OPTIONAL STEP: Now that you’re looking at the side of the engine, take note of the crank pulley. In the picture above, it’s the black pulley located in the center of the image. You’ll notice that on my car the pulley has a black ring that appears to be “swollen”. This means that oil has been leaking into the rubber dampener located within the pulley and has damaged the dampener. If possible, you should replace the pulley while you’re working on the coolant pump. If the problem isn’t addressed in a timely manner, the pulley might come apart and cause your accessories (AC, alternator, water pump) to stop working. In extreme scenarios, you might damage the engine itself. I’ll write up another tutorial on how to do that repair in another post.
  4. Use your 10mm thin wrench to remove the 3 bolts off of the pulley. Since it’s not directly driven by the belt, you should be able to hold one side of the pulley with your left hand and use the wrench with your right. All while “hugging” the brake/caliper assembly. Not the most comfortable of positions, but it gets the job done.
  5. Once that’s loose, work the pulley out of that spot by pushing it over to the left (away from the front of the car) and pushing it back (towards the center of the engine). It takes a bit of wrestling, but it eventually will come off.
  6. Now comes the fun part! Using your thin 10mm wrench, remove the top bolt of the water pump first by using the “hugging” method described above. . It’s very important that you work on this bolt first since it’s the most difficult to remove.
  7. Next, remove the bottom two bolts using either the 10mm wrench, or a normal socket wrench.
  8. Finally, remove the two center bolts. At this point, you might want to place a bucket under the pump. Coolant trapped in the engine block will begin to bleed out and make a mess if you’re not ready.
  9. Once the engine is finished spitting out coolant, finish removing the bolts and work the pump out of the crevice. Make sure the gasket comes out with the pump. If it doesn’t remove it using a knife/screw driver GENTLY!
  10. Spray the area with some brake cleaner and clean with a rag. The opening should look like this:[singlepic id=786 w=320 h=240 float=]

Break time #2! Congrats! You’re half way there!! Time to ponder why the heck MINI thought it would be a great idea to make that part entirely out of plastic and also why the replacement is cast aluminum.  Go drink a beer out of frustration. Don’t work on your car if you’re tipsy or drunk. Moderately sober is okay. Don’t drop the car on your head.


  1. Reassembly time! Basically, just assemble everything in reverse order.
  2. Place the pump in the spot you just cleaned, replace the bolts, starting with the top one. Make sure that everything is torqued well. Not sure what the torque spec is, but make sure it’s tight!
  3. Next, wrestle the pulley into place just like how you removed it. The pulley fits, trust me. Once again, make sure that the bolts are tight!
  4. Reassemble the wheel liner starting with the “left” side first, then move the right side into place. Make sure you clear the spring/strut!
  5. Remove the towels and reconnect the hose you took apart under the radiator.
  6. Lower the car and once again support the engine using the jack. Try to place the jack on the “left” (away from the front of the car) side of the oil pan. You’ll see why in a minute.
  7. Reattach the wiring harness and the 10mm bolt you removed behind the block.
  8. Lift the engine enough to attach the mounting brackets back onto the block. Use an impact driver if you have it. If not, use a wrench and tighten VERY well. Remember, you should attach 4 x 13mm bolts and the 13mm nut/bolt combo for the ground strap. Make sure the ground strap is firmly attached! It’s VERY important!
  9. Here comes the part that requires muscles! With the help of a 2nd person and the pry bar, use some leverage to move the block over the 18mm bolt. If you need to adjust some more, use the box end wrench to push the block onto the bolt. DO NOT USE YOUR FINGERS! YOU WILL CRUSH THEM!
  10. Once you’ve got the block over the bolt, lower the jack and let the engine rest on the support. Tighten the 18mm nut.
  11. Double check that you tightened everything well and didn’t forget the 10mm bolt or the ground strap!
  12. Reconnect the black tube you removed. Also reassemble the black bar you removed earlier.

Optional Break #3. You’re so close! Screw the break, just keep working! (Chug a beer if necessary)

  1. Reassemble the engine bay. This includes the black bar, headlights, tube, etc.
  2. Fill the car with coolant. There will be air bubbles within the system, so refill the reservoir slowly.
  3. Let the coolant work it’s way throughout the plumbing in the car, but DON’T START THE CAR YET!
  4. Give it 10 ~ 15 minutes to work its way into the system. Once you don’t see a large change in coolant levels in the reservoir, start the car. CAUTION!!! DON’T START THE CAR WITH THE COOLANT RESERVOIR OPEN! YOU WILL MAKE A MESS AND BE SAD (not to mention it’s dangerous)!
  5. Open the bleed valve on the thermostat housing and keep open until you notice coolant leaking out of it. Close the valve. Refer to my previous post on how to replace the thermostat housing for a description of where this valve is located. You’ll need a long standard screwdriver to open/close it.
  6. Let the car get up to temperature by turning on the heater. Once there, turn off the car and add coolant as needed.
  7. Once the reservoir has been topped off, drive the car around the block a couple times. Top off again if needed. Monitor fluid levels for the next couple days and take note of any new spots under your car. If you’re still seeing spots under the car after a couple days, jack the car up and take a look under it. Your thermostat housing might also be leaking.

Mandatory Break #4! Congrats! You’ve performed a major repair on your MINI! Drink lots of beer and don’t drive the car you just fixed! I mean, you just went through the trouble of fixing it, so why risk it, right?

  1. Profit.