I replaced my thermostat. The water pump pipe came out and I just pushed it back in. When I was installing the thermostat, I heard a pop, which I assumed was the pipe seating itself. When I poured water into the reserve, it just leaked out under the passenger side. I assume the pipe cracked. Should I replace the pipe and water pump?

 

We recommend removing the thermostat housing and pipe for inspection. If there was a 'pop' during installation caused by a break, it should be fairly easy to see.

If it weren't for the 'pop', I would suspect the o-ring or the retaining clip on the water pump pipe may have been dislodged. In any case, you will need to remove for inspection.

Here is a video that may help!

 

The video is great. Wish I saw this before replacing the thermostat. When I removed the thermostat housing, the water pump pipe was already loose from the water pump. I had to work a bit to get it released from the thermostat housing, so I think the other end (attached to the water pump) was either cracked or damaged. I read that the seal swells so it would be hard to get it back into the water pump, unless the seal is changed. I didn't know I could just pull out the pipe (after removing a wire) to inspect it. I thought it was too long to remove from the thermostat side vs the water pump side. I just left it there, and attached the thermostat housing to it, and tightened the three housing bolts. And the end of tightening the bolts, that is when the pop sound occurred.

Once I filled the radiator reservoir, the water leaked out quickly near the water pump, so guessing that the pipe is cracked, or not set properly.

The mini has 90k miles on it. I don't know if a shop can inspect the pipe from below and tell that it was cracked or not.

 

Going to double check with our resident expert and get back to you shortly!

 

It is doubtful the problem can be spotted from below, and it is likely you will need a water pump and pipe. Sorry, probably not the greatest news but we'll help the best we can. There's a 10% discount available this month on parts. NAM10%Off at checkout. I didn't catch your year or model, but here is a link to the New MINI page with these items.

http://new.minimania.com/Search_Resu...20pump/default

http://new.minimania.com/Search_Resu...20pipe/default

 

I am replacing the clutch, so I have the engine disassembled. I replaced the coolant hoses, and the thermostat crumbled in my hand. While removing that, the pipe dislodged, and it turns out that the o-ring and groove simply snapped off in the pump orifice. I've 116,722 miles on the odo, and given my experience, just assume that all of the hard plastic bits are all shot. The thermostat & coolant pipe were more brittle than Pringles. I had the water pump replaced by MINI at around 65k, and I'm probably going to replace it since it's easy right now.

 

If anyone is changing their thermostat and haven't changed their water pump pipe, then do them together. The pipe will probably wear out soon after the thermostat so it's easier to change it at that time. Well worth the cost of the pipe, or the labor of you take it in. That should be part of all the thermostat diy instructions

 

The amazing thing is that the thermostat was still going strong...but it was likely on the verge of failure. The pipe broke with an absolute minimum of force. I agree, the pipe should always be included in a thermostat replacement DIY.

 

Happens often. Im in the middle of rebuilding the entire r56 engine and when removing my pipe it shattered where the o-ring is. A metal pipe would be great for this.

 

Is there any real advantage to going with a genuine Mini waterpump vs the cheaper Febi, Grafs, or Hepus? Since there is no way for me to personally see them, I'm hoping someone on here has done a side by side comparison.


I notice the part numbers for the non Mini brands are mostly 11517550484, with a 1158604888 thrown in on an ebay site for Genuine Mini, vs the Mini one listed in Realoem which is 11517648827. What's the difference? Also what is the correct Serpentine belt size? 6Kx905 or 6Kx894? I see both listed but the Realoem shows 905. I need to order some parts, including these, so I want to get it right the first time.

 

Would strongly recommend OEM quality with these sometimes finicky motors. We offer a Value Line that is OEM spec and less expensive, depending on your year and model.

http://new.minimania.com/Search_Resu...20pump/default

Here is a complete listing of Value Line parts available:

http://new.minimania.com/Search_Resu...e%20Line/Parts

Please let us know if we can help!

Drive Hard. Drive Safe. Keep Grinning.

 

We all know Mini doesn't make water pumps. It is more than likely either a Graf, Febi, or Hepus. So saying a recommendation for OEM quality doesn't tell me anything, sorry. The OEM pumps are what is failing. And likely to continue to fail. My gut is the Graf or Febi, but I have no way of knowing which (or both, or someone else) were OE suppliers to Mini. Your site actually gives NO manufacturers for the water pumps, for either OE or "Value line".

 

You can see the end of it below, but it can crack inside the pump housing or anywhere else.

For my thermostat housing and water pipe experience see this thread: https://www.northamericanmotoring.co...questions.html