I have my r53 back together and after pretty much taking everything apart and servicing, replacing parts/gaskets, upgrading, and now I have a coolant leak. It looks as if it's coming from the flange area. I put a new water pump on and O ring, but I didn't replace the flange because it look good. So now I have a new flange and two new o rings. My question is should I go about this the same way I removed the supercharger or can I take the water pump off while the supercharger is still on? I'm not looking forward to disassembly again, but I gotta do what I gotta do.

 

Ok, I’ve confirmed the coolant leak is coming from the water pump flange, but not from the mating surface of the engine, but the inside where the water pump O ring seals. The water pump and O ring are new. What are the possible scenarios that could have gone wrong leaving me with this leak? I have a new flange and O rings ready to install tomorrow, but I’m praying I don’t disassemble, reassemble and still have a leak. Lol.
Now, nice I’ve only done this once and I ran across a video where they removed the water pump without removing the supercharger. What route is best to go? The only thing I fear, removing the SC, is removing the dipstick and accidentally getting coolant in the oil pan.

 

Not that anyone responded, lol, but I found my leak. Pinched the O ring.

 

A shame you had to pull it apart again to ID the problem. Good habit to get into to always lube (spray a little lithium grease on 'em) the o-rings prior to assembly. That helps prevent this type of issue.

 

For sure this time. I took the old flange off too this time. The new one came with the O rings, but I noticed the old flange had the O ring and black RTV. I just need to clean the surface and use the O ring only correct?

 

Yep. Definitely no need for RTV on o-rings.

 

Back together, around the block a few times, and no leaks. Needed more coolant than I thought. Started to overheat, added, more bleed and staying at optimum heat levels.

 

 

Just in case someone changes their flange. You’re not going to tighten it all the way down I till you re-install the supercharger and have the water pump correctly seated into the flange. The reason I say this is because there is lots of play with the flange and no way to know you have it centered correctly. I didn’t realize it until I had to brainstorm how I was going to align the flange to the water pump, but you can access the flange bolts with a long extension through the water pump housing.

I did see a video we’re a guy replaced the water pump without removing the SC, but I found it easier to just go ahead and remove the SC and water pump together to complete the task.

 

Nice exhaust tone. What is it?

 

It’s Milltek

 

Oops, deleted

 

oops