I was just watching coolant flush videos from modmini. its a pita! it occurred to me that the bottom hose you take off is accessible at the top of the motor. there is a connector there. whats to keep a fellow from disconnecting it at the top, running a semi rigid water 1/4” line (like for refrigerator) down the drivers side to the bottom of the radiator pickup, attaching a 1gal/min peristaltic or aquarium pump and siphoning out fluid that way? not only does it require almost no disassembly, it pulls from the bottom of the radiator. you could also put the rear wheels on a ramp to get the fluid towards the front.

what am I missing? will this work? do we still need to drain the block (not sure if the r52 has a block drain plug?!)

the hardest part will be weaving the 1/4” tube down to the bottom of the radiator but it looks like a pretty straight shot to me based on front end service vids ive seen. by measuring the tube inserted, youd know of you were at the bottom. one could also melt and round the end of the tube to assist to push to the bottom.

 

That sounds like more work than just jacking the car up and popping the lower hose off. I don’t know of anyone who bothers with the block drain plug.

 

Thought it needed to go into front end service mode to get the hose off?!

 

Well, IIRC the R53 has a slightly different radiator, so maybe it’s different. I’ve never put my R50 into front end service mode to change the coolant.

 

OK, so you can just reach the hose from the bottom? Cool.

It looks like I was mistaken on the driver's side path - it goes to the water pump first I think. Its the passenger side, but that goes to the top side of the radiator. I don't know if that radiator bung would gain access to the bottom of the radiator.. I wonder if the passenger side of the radiator is just open, or are there channels along the height there? I tried to find a cut away picture to no avail.