I have a 1967 LeSabre w/340. About two years ago, I noticed coolant spill out when I shut off the engine after a shorter drive on a very hot day. The "hot" light came on shortly and went off again or maybe flickered a few times. I simply refilled the radiator, blaming the weather (around 100°) and slow traffic for the spilling. I filled up the coolant until like 2" under the radiator cap and, if I remember correctly, I believe I saw a stream of coolant through the radiator opening, about the diameter of a pencil, from the driver side to the passenger side, when I ran the car. I parked the car shortly after in a remote place for some months. Last year, I noticed at some point that coolant was missing (about 2 quarts). It may be that the radiator spilled again, I don´t recall. I flushed the radiator and replaced the coolant with a new mixtured. That time there was no stream of water in the radiator, just the coolant "sitting" there when the engine ran. During the season, I filled up coolant once or twice, but minor amounts, and noticed a little coolant down by the fuel pump. I suspected the water pump not working correctly, but as the engine and tranny were pretty much oil crusted, I wasn´t able to locate where exactly the green drips were coming from. The most greasy and wet spots were around the distributor (under thermostat and on top of water pump housing), the oil pump and the fuel pump, the oil pan, of course, and on the block under the water hose fitting on the rear passenger side of the engine. Also the tranny housing on the passenger side, where the dip stick hose mounts. I knew there was work comin up, so I cleaned up the motor and transmission to locate, where water and oil may be coming from. I noticed at that time that the water pump housing showed some corrosion on the lower part. I then parked the car over the winter (no, I don´t drive her that much...) Yesterday I had to fill up about two quarts of coolant before I drove her home from the remote parking space. I was not able to locate any dripping and/or fresher puddles unter the car (that said, the floor is stained with old fluids). The oil and ATF levels where ok. Re-checked this morning in my tiled garage, again, no puddle. Now: Where does my coolant go?? I hope it just drips out over time, although I haven´t found the leak yet. I definitely suspect the water pump and already got a new one, together with all kinds of gaskets for intake manifold, valve cover, oil pump and so on to re-seal the engine. I pray I do not have a cracked head or block or blown gasket and the water goes into the oil. How would I check this? Then again, shouldn´t I notice, if two quarts of water were in my engine oil? I mean, first, the level on the dip stick should be way above "full" and second, the oil should feel "watery", shouldn´t it? Can coolant go into the tranny? I have a tranny cooler as part of the radiator and the rad internal looks pretty brown through the top opening. I believe it is the original radiator as the car only has k75 mls on it and had been stored for about 3 decades. Again, the ATF level does not rise noticeably and the drive is smooth, although the car "rocks" once, when I go from P to R or D. Can the rad be preassure-tested?
If you have two over flow hoses, they can get switched around and it will spill out when hot down the road and then next morning you start her up it will seem low till warm again.
Sounds like you need an overflow tank, and you have something seeping above the fuel pump, which would probably be timing cover, gasket, thermostat house, or intake gasket. I would clean the area. Simple green and a pressure washer will do pretty good to clean
There is only one overflow hose, located right underneath the radiator cap. It is routed down onto the radiator support, clamped with a bracket. This looks very original. Also, there is no overflow reservoir nor does it looks like there´s ever been one. No brackets or mounts or anything.
Thanks for suggesting, but I don´t see how that would solve the problem. A tank would simply keep the coolant from spilling in the street. This is NOT the main problem. If the system was designed this way, so shall it be. The problem is that the coolant level in the radiator falls WITHOUT water noticeably spilling out.
coolant expands alot as its heated. And coolants now Expand more then coolant from the 60s. So yes , this is issue number one of your problem. It is going on the street. In minor amounts as you mentioned.this is normal for that design. Number 2 is you need to clean the block and inspect it with a pressure tester on it to the proper pressure. About 15 psi. Its an old car, could be a gasket, freeze plug, weak radiator. If you worked in the maintenance field you would know this.
Some thoughts. 1. Change the oil, see if there is water in it. 2. Check the trans fluid level and see if it has gone up or is milky. 3. Try running with a lower pressure cap. 4. If radiator is the original brass/copper, they start springing pin holes when they get old, so it might be pin holes that don't show leaks until the pressure build up in the radiator. 5. Could be leaking water pump, hose, or various other things under hood. My old radiator worked fine when temp was below 85. When temp would get up into the 90s, it would overheat and start spewing water. Only solution was to replace the old corroded radiator with a new aluminum radiator. Now she handles 110 degree days with no problem and no spewing.
I would install an expansion tank for the radiator. Clean all the gunk off the engine and such and go from there. I see a lot of classic cars, GM's Ford's, mopars etc.. that have an aftermarket expansion tank installed on them. Expansion tanks will eliminate that air pocket that sits in the radiator, that causes rust & corrosion. Keith
The thing that a catch tank does, is that it keeps the radiator full all the way up. That allows the top rows to help in cooling the engine. The old design without the tank was designed to run 2-3" low. That left room for expansion. Put any more in and it would blow out as soon as the engine got warm. Jim
Should I be able to see a stream of water tru the rad cap opening when the water pump is operating properly?
When the engine heats up and the thermostat opens, you can see the water flowing through the core. But I wouldn't take the cap off and look at it with a hot engine unless you need a new face.
The thermostat needs to be open, so it will be very hot. But you should see some movement, possibly need to rev motor alittle.
If there is no sign of coolant on the ground , the u may have a head gasket failure. Been there; done that - replaced the head gaskets on my gs 350 in spring of 2018. I was losing coolant with no apparent leak.
I have to say, refusing to add a coolant recovery tank for the sake of originality is only worthwhile on a 100 point Concours car. Otherwise it's way better to follow what the factory did later on by adding the recovery tank. They recognized (sometime in the very early 70's) that it brought real advantages with it. Not only did the new cars stop polluting the environment with antifreeze nearly every time they were driven, the need to add coolant on a regular basis was dramatically decreased, and radiators became noticeably more efficient. Cars also began to overheat less often, and smell better. If originality is that important to you, look for the first year that your model had a coolant recovery bottle and incorporate that into your car. It is extremely likely that the engine compartment in that area was unchanged during that time period and that the later bottle will fit your car just like it did the later one. Jim
You can lead a horse to water but you can't make them drink. Some people are just stubborn and don't realize a good thing even if it smacked them in the face. Keith
