My "new" 51 Hornet is leaking water out the radiator overflow. The temp gage was stuck on Cold so I put in a new water temp sending unit. Now the temp at idle in garage is a little below half way.
Noticed hot water coming out of the radiator overflow tube and checked the cap. Sure enough it was bad and I put in a new one with 7lbs of pressure. Cranked up the car and let it warm up and after a few minutes it was leaking again out the overflow. Temp gage says it is still below the mid-point.
I would have thought it would be overheating if the radiator was bad and needed recoreing.
Any suggestions or comments?
Are you over filling? One needs to leave some room for expansion.
Do you have the correct cap? Hudson radiator has a "deep" filler neck/
Standard cap will fit but not seal.
Good Luck.
I tend to fill it to the ring just under the radiator seal which I guess is full. That would not leave expansion room. After driving it about ten miles the water was only down about an inch or two from the top. Maybe the problem s me over filling.
Hi Gary, I finally managed to get into this Forum by changing my password several times. I am usually on the other Hudson Forum, as this club one is hard to get into and use.
As for your coolant seepage, I think you definitely overfilled the radiator.I also sent you an email. I doubt there is any exhaust leak now that you stated you filled it all the way up to the rubber seal ring. Kenneth
Use an overflow bottle allowing you a FULL radiator and never lose water again !! Take it off when you are at Pebble Beach~~
Great idea! Thanks
Recommend the one at Advance Auto w/the thin rubber gasket. Use the gasket for return syphoning to work with old caps. What I have.
Can you tell me the model you are using? They have an entire selection and I would prefer not to reinvent the wheel. Thanks. Gary
Do not know--using in 2 cars: white plastic bottle--square with clear hose and thin rubber washer. cheap !! Not online that I can find.
Gary, as Ken said drop the level to half way between the tanks bottom and the radiator neck or at least 1-1.5 inchs below the neck. Also the correct cap for 1950 -54 is an AC RC-3 7lb.A Stant R-6 is good also. The depth of the neck is 1 inch & needs a pressure cap with that depth. Many , if not most cars of the period used caps with only a 3/4 inch depth. Therefore, the lower seal on the cap is not touching the neck lip, and therefore 0 PSI.
I use Stant 10206. It is the correct long neck 7 PSI cap.
That is the new crossover number for Stant. Interesting note: About 1953 the AC Division changed the nomenclature numbers to be separate from the GM part number. Before the mid 50s the 1 inch deep ,7 pound caps were stamped, on the cap itself, as 13 with a 7# below the 13 on one of the ears. This coincided with the GM part number 846713. This was confusing, so AC assigned the letters RC -3 ( R adiator C ap -3) as part number 850797 & probably for the next 30 + years that is the way they are listed. About 1960 the AC replacement caps had a very pretty blue,red & silver color. The RC-4 is 1 inch deep but 4lbs PSI.
Guys, These cars were built without a overflow tank and do not need one. The water you see coming out the overflow is from the expansion of the water getting warm. There is nothing wrong with the car and nothing needs to be added. As said earlier leave some air space in the radiator. About 1" or just let it overflow the 1 time once the engine has made it to operating temperature. It will stop and never overflow again unless you fill it up too much again.
Don't need overflow bottle. The top tank is not supposed to be full. In practice, if the fluid just covers the top of the tubes whwen the engine is cold, it will work perfectly.
Overflow tank not needed. The top tank is not supposed to be full. Actually, if the fluid just covers the top of the tubes when the engine is cold, it will work perfectly.
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