Bypassing Radiator during FLUSH???!!!
 

I'm putting in a new rad into a 87 300D, and want to flush the system before refilling it with MB fluid.

Would anyone NOT recommend bypassing the rad to do a flush, I don't want to flush with the new rad in place, as it will get contaminated, and I don't want to flush with the old rad in place, as it will take much longer with all the debris in the old rad and probably just carry those contaminets into the engine/head during the flush???

I will be keeping an eye on the Temp Guage the entire time so that it does not climb above 100C during the Flush W/O a rad.

I'm not going to use Cirtic Acid as I fear it will attack my already volnurable head gasket, instead a Regular Prestone flush is what I'll be using.

Let me know what you think...

The problem is that you will only be able to run it for a few minutes before approaches 100C, then you have to wait a couple of hours and do it again. It's going to take a while to get a significant flush completed.

I would probably just do the flush with the old radiator in place unless you suspect there are some big chunks in there.

im sure after you do a rinse run a once or twice youll get all the corrosion chunks out of your head that came loose from the rad. Dont worry about it. your being too technical.

take the t-stat out and shove the hose in the bottom radiator hose with the radiator out, there should be no issues. At idle even if your engine goes over 100C it still is unlikely it will cause any permanent damage.