I will admit this is not a 300 only problem but it is related to my 1946 Chrysler straight 8 overheating. After much diagnosis and confirming the water pump, t-stat, water distributing tube and hoses are in proper working order I finally was able to borrow a small video probe and confirm the problem in the upper tank of the radiator. BTW, There is a large baffle that prevents viewing any portion of the top header without the camera. Years ago while the car was in the assembly process some mice secretly made a nest in the upper tank. No amount of back flushing will dislodge all of the blocked tubes (verified with the camera). This radiator was in the car for 2 years and the result was dislodging of some of the material but major overheating (obviously). The car is now not even drivable for more than 5 minutes. No radiator shop in Kansas City (even the OLD) ones will take the tanks off this radiator and clean it - they say the tank to header hem will be brittle and not survive reassembly. I am left with a re-core (just to clean lint out of the upper tank?!?) at an estimate from two sources at $7,000 (that is not a typo). The tanks/headers are not flat and the radiator is sort of an octagon shape. I have considered just replacing the radiator with a modern custom radiator but this is an AACA Grand National car and it seems a crime on several levels. This brings me my question. Is there a chemist out there that can offer an acidic or caustic product that might dissolve the fluffy lint like material and NOT harm the brass, solder, etc? I know from chemistry class that there is something out there that will dissolve the organic lint and leave the metal clean and bright. I do have two trashed radiators available for product testing. I know there used to some cooling system cleaning products but the environmental issues seems to have eliminated most of the old products. Any suggested ideas are appreciated. .Jack Jack Boyle (913) 544 4650 Enjoying the same C-300 since 1967 IMG_0623 small [Non-text portions of this message have been removed] ------------------------------------ Posted by: "Jack Boyle" <jackcboyle@xxxxxxxxx> ------------------------------------ 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 https://groups.yahoo.com/neo/groups/all/manage/edit 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#querylang ------------------------------------ Yahoo 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: https://info.yahoo.com/legal/us/yahoo/utos/terms/