Hello Group - When replacing a leaking original freeze plug on my 1957 300C, I discovered a considerable amount of rusty crud packed up on the backside of the old plug. Although I used a bent wire to pull out several more tablespoons of "mud", I'm certain that same situation exists throughout the rest of the engine. The engine is not yet running, so I can't use the typical radiator/block cleaners that rely on the engine to pump the cleaner solution through all the internal passages. Not only that, but I have just reinstalled the newly refurbished radiator, and wouldn't want to flow debris-laden fluid through it, anyway. I would also want to ensure that the heater valve is closed so debris is not introduced into the heat exchanger core. So, I'm thinking of introducing an appropriate fluid into the block/heads while isolating the radiator (remove hose and plug that opening) and heater. I will be replacing the thermostat, so I could introduce a hose (maybe even my pressure washer!) at that point, add a cleaner and let it sit for several days, if necessary, then drain out whatever crud I can through the lower radiator hose opening. I could repeat that process several times until the flush fluid becomes sufficiently clear. I could also take out the neat removable/reusable stainless freeze plug I just put in and let the dirty fluid drain from there, too; however, I know that doesn't do anything for the opposite side of the engine where I just cannot get to a freeze plug at all. Do any of you have some suggestions for how best to clean the coolant passages in my non-running engine? Technique? Best chemicals? Precautions? Pitfalls? Thanks for your help. Ray Melton Las Cruces, NM 1957 Chrysler 300C convertible white/Gauguin S/N 3N572517 [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/