Extremely well done DIY, kudos.
I've done 3 flushes, but no hoses on mine yet. Have done several expansion tanks on others though and found a few tricks. First, if you don't want/need a coolant bath when taking off the engine side drain plug, get a piece of 1 1/2" sump pump hose about 2' long. Break loose the bolt and shove the hose up around it. Push back the hose (its flexible enough to do this) until you can get your fingers in to loosen the bolt. Once it pops free, push the hose back against the block and let the bolt flow down the hose along with the remaining coolant. I have done this many times and nary a drop has spilled. With the expansion tanks, its best to remove them while still attached to the bracket. Its a whole lot easier seperating them outside the vehicle and lessens the possibility of breakage. One I did we simply replaced the tank and the bracket with new pieces and installed as one unit. SO much easier. Other thing is if you flush your system with distilled water as you have, fill system 1/2 amount of total capacity with STRAIGHT coolant, ie; 2 gal. capacity, 1 gal. straight coolant goes in. Then fill remainder with distilled until full. This compensates for the distilled still in the system after the flush, which can be as much as 2 qts. If you pour in 50/50, it will be seriously diluted. While not too bad for milder climates, it WILL freeze in colder ones. Plus, it doesn't give you the full boilover or corrosion protection regardless of outside temps. Also, I caution the use of WD-40 as a penetrant on any plastic parts. It has the ability to soften some plastics due to the solvents in it. And we know how weak the plastic components are on a BMW. I use spray silicone instead.
Last edited by shortyb; 07-20-2010 at 09:02 AM.