MINI R56 coolant pump

I was asked to carryout an investigation Friday to check for a coolant leak. After filling the cooling system no leaks seemed to appear, however when I pressure tested the system a serious leak appeared from the coolant pump. I looked under the bonnet and thought I don't fancy trying to change the pump on these engines?

Saturday morning I was given the job of changing the pump. AD list a time of 1.60 hrs. I said to myself I don't think I can't do it in that time. Never having change a pump on these MINIs I decided to UTube it. I found an N12 model and watched him with his procedure to remove the pump. According to AD it takes an hour to remove the water pump pulley and everything else can be carried out in 0.60 hr?

AD also point out that the cooling system fan must be removed? I found that statement very interesting!!

The video was helpful but I hate it when the video keeps being stopped and restarted. Clearly the presenter is coming up against issues he does not fully understand and therefore restarts the video after the event of struggling.

The video appeared to suggest that all work up to removing the pump was carried out from underneath the bonnet. As I said the video kept stopping and starting. I found most of the work is not carried out from underneath the bonnet but through the drivers wheel arch area.

I found that the following routine worked for me...

1/ Remove both headlamps,
2/ Remove the lock panel,
3/ Place a suitable jack underneath the engine sump pan. Make sure it is padded.
4/ Support the weight of the engine using the jack,
5/ Remove the engine mounting. It was not necessary to remove the mounting from the chassis,
6/ Remove the engine alloy support engine mounting from the engine cylinder head/block,
7/ Tie up the wiring harness high up at the front of the engine,
8/ Lower the engine as far as it will go.
9/ Remove right hand road wheel,
10/ Remove front section of inner wheel arch liner,
11/ Working from underneath the drivers wheel arch.
12/ Pull the water pump tensioner plunger fully out to detach pully from water pump pully. (You may need to clip it to keep it in the outwards position)
13/ Using a suitable holding pulley stop the water pump pulley turning and remove the three 10 mm bolts.
14/ The pulley can now be removed from underneath the arch/chassis area.
15/ You'll see 4 (10 mm) bolts securing the water pump. Trust me the video said the same. Actually there are 5. The fifth is hidden at the 12 o clock position not readily seen.
16/ Having removed the four bolts my pump detached readily from the engine.
17/ To remove the pump, move the pump towards the bulkhead area and bring out over the top of the A/C pipes/hoses. You may need to pull slightly on the hoses but the pump will easily come through.

I knew the pump was seriously leaking when pressure tested but the seal area and drain hole were dry and intack. I asked myself what then was leaking as nothing else was in that area!

This is the time when I looked back at the engine block and could see part of the plastic housing of the pump still bolted to the cylinder block. I then looked at the water pump and could see the pump body damaged. How did it become damaged?

Renewal is the reversal of the above. Actually doing the job by the above method makes the whole task of changing the pump very easy.

Obviously the eagle eyed among you will have noted that I did not drain the coolant prior to disassembley?  

After priming the cooling system and letting the engine run with the heating system set to hot, I put the scanner on to see if any software showed a function for driving the water pump. Now although the water pump is mechanical, the plunger I pulled out the tensioning device is electrical, hence I looked to see if the software had a drive/test function for the pump, however, snap on D7 had no such software/driver for the pump operation. The cooling system did seem to function okay afterwards, and the heater blows hot.