Chuckin out water

F

fisher

Junior Member
when driven hard my Model A chucks water out of the radiator quail cap
I dont think it ii necessarily Boiling

Donald Fisher
 
When you get back home do you fill the radiator up again ? Most Model A radiators will seek their own liquid level and get rid of the excess. Or, you could have another issue. I had that problem and only cured it with a new radiator as the old one was pretty well blocked up. Even a radiator shop "boiling" did not help.
 
I had a similar issue, I got a set of upper and lower gasket and the lower one worked fine but I made my own upper one from a large rubber washer I got at Sears Hardware (Just cut it by hand. I've had not a drop, splash out since...) You want just enough pressure as to not damage the quail. Buy a few washers as it took some playing around with it to get it to fit just right.

20140405_191620.jpg
 
Had the same problem with my 30 coupe put in a 160 deg. thermostat and ground 1/3 off of the impeller, no more problem.
 
When I first started working as a mechanic, most cars did not have overflow tanks. The rule was to keep the coolant one inch below the bottom of the radiator neck. When I got my model A i did the same thing, didn't, work the radiator would kick out the coolant so it was two to three inches below the neck. I put in a thermostat and that helped but the coolant was still more then one inch below the neck. So I used the large head nail (copper) in the overflow tube. That worked! Level now stays one inch below the neck.
 
In addition to the useful advice above make sure the overflow pipe is clear, and have you by any chance recently replaced the head gasket?-it make need re-torquing
 
Sometimes we have to be "inventive" to get the cap sealed TOTALLY! AND, it has to be sealed TOTALLY to function right! Suppliers sell assorted thickness gaskets for the flip caps, sometimes you can use a large, skinny "O" ring.
ALSO, make SURE your overflow tube is not plugged by rust or crud or mud daubers or them bugs that stuff them full of rolled up leaves!
If all else fails, jist go back to the stock cap.
By the way, at cruising speed, if yo' MOTO-Meter goes UP & DOWN at very regular intervals, you're LOW on water! The nail helps keep your level up, so's the WHOLE system ain't full of air bubbles, & air bubbles WON'T dissipate heat. A coolant overflow tank, hooked to the bottom of the overflow tank is a plus in keeping the system full of water. If you use an early Volvo expansion tank, that uses a 5 LB pressure cap, then, VOILLE, you have a PRESSURIZED SYSTEM!!
Bill W.
 
Hello. New to this forum and to the world of vintage cars. One week ago we were given a 29 model A from a family member to care for and eventually pass along to the next generation. I have put about 75 miles on it without any issues. 2 days ago, in cool weather, and about a mile into a short drive, the radiator "bubbled over", not boiled over, with a foamy overflow that looked very much like the foam on a root beer float. The water level was down about 1/2 cup. The shroud was not especially hot. Any idea what this could be?
I did look through many threads and there seems to be many different opinions on what to put in the radiator after a cleaning at a shop. Anti-freeze or not? Only distilled water? No hard freeze here in the northbay area of SF. At least not for many months. Any help would be appreciated.

Brad
 
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Your radiator cap should not leak water, for any reason.
Work with gaskets, until you have one that does not leak.
Make sure that your overflow is not plugged, first.
MIKE :) (mikeburch)
 
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