Hmmmmmm...I would say that the cars that you are speaking of may have had unmaintained cooling systems. Also, in addition to overflowing, those cars could also have had low coolant levels due to a minor leak someplace in the system. An overflow kit would not help that problem. Aside from that, water levels are suppose to be checked regularly. My old Imperials don't lose coolant, and don't have overflow kits. I check them often, and they never seem to be low, but they also get serviced once a year. I keep the level at about one inch below the top filler neck of the expansion tank. This means that the top tank is about half full when it is cold. Service stations always want to add to fill it up, but that is what the old manual refered to as "overfilling". My dad's '60 lost coolant out the overflow when we first moved here from Southern California in 1968. Everytime we went someplace more then 10 miles, the coolant would overflow after the car was shut off. I later found out that because the car was overheating, the water would tend to boil after it was first shut off (since the engine was still hot, and the water wasn't circulating). My father put an overflow kit on it and managed to keep it from overflowing in the driveway, but it still seemed like the car was gurgeling after it was shut off. When the car was turned over to me in 1985 the radiator began to leak. I removed it and took it in for repair. The shop found that it was plugged up with minerals (apparently from the water down in Southern California and my father's lack of maintenance) and had to have a new core. After the radiator was repaired correctly, the car no longer overflowed after it was shut off. My father's unsightly home made over flow kit (plastic milk containers linked together with rubber hoses)was removed and put in a box in my garage. Ever since then he has been telling me that the overflow kit needs to go back on the car, but I have yet to see why. My '65 Imperial use to overflow in the driveway after it was shut off and my dad told me that it was because it didn't have an overflow kit. I later found that it was also over heating. This was because the heat riser valve was stuck closed and causing the engine to over heat. After I repaired the heat riser, the engine ran cooler, and the the radiator did not overflow. I had a friend with a '47 Chrysler New Yorker. When ever he took it on the freeway it would overflow at stop lights. Several mechanical friends told him that it needed an overflow kit. It turned out that the internal water distrubution tube had rotted, and was no longer functioning. Once it was replaced it no longer overflowed when it came off the freeway at stop lights. Newer cars have much smaller radiators than the old Imperials did. They are made out of weaker material to save on cost and weight. They do not have large top tanks like the old Imperials did. For these and other reasons, they must have overflow kits. Their cooling systems were designed to be set up that way. The old ones were not. Like I stated before, adding an overflow kit is a fine idea, but it really should not be necessary. If it is, nine times out of ten, there is something else wrong with the car that is causing it to overflow. If you refer to the old shop and owners manuals, they state the proper coolant level. They also state that if the correct level isn't "maintained", the car will either overheat or the radiator will overflow. Most Americans have never maintained their cars as they were supposed to be maintained according to the shop manual. By not maintaining the cooling systems many cars have clogged radiators when they are only a few years old. I would not hesitate to say that if you saw a lot of cars with overflowing radiators during the '50s you were probably looking at cars that needed work. As well as I maintain my cooling systems, I have found that it has nearly become a matter of routine to replace the raditators on my newer cars. They seem to fail after a few years no matter whether they have been maintained or not. This has not been true of my Imperials, however. I have even purchased used radiators and found them to be completely servicible without any repair. That speakes very highly of the original quality of those older parts. Paul In a message dated 11/9/2003 8:50:05 PM Eastern Standard Time, DONALDDICKINSOND@xxxxxx writes: > Very interesting Paul, but I vividly remember cars in the fifties and how >they were constantly low on coolant as it apparently went out the overflow >tube to the ground. I also remember how neat I thought it was when a simple >thing like the > overflow reservoir was added to solve this problem....