Coolant Spraying From Radiator Cap in my 1931 Ford Model A Pickup - The Fix

Several months earlier, I had drained and flushed the radiator and added about two and a half gallons of new coolant (Watch my video titled, Changing the Coolant in a 1931 Ford Model A Pickup.” The capacity of the cooling system is around three gallons. After changing the coolant, every time I went for a 15-minute drive or longer, at about 35-45 mph coolant started spitting from the radiator cap striking the hood and windshield. I did some basic troubleshooting of the water pump, fan belt, spark plugs, etc., but could find no reason for the spitting coolant. Then when I mentioned this issue to a fellow member of the Sequim Valley Car Club, who also owns a Model A. He told me that I had likely over-filled the radiator, and that when he changes the coolant on his Model A, he fills it up to where he can see if looking into the radiator cap, then he drains out about 16oz. Well, his solution from experience worked for me too!

[@andy41417]

Be sure gasket is actually sealing the cap. Put a piece of rubber on top since coolant was leaking past a bad rivet. Any overflow should go to the ground via the tube. Also put a purpose made thermostat in the top hose can help. Ultimately if driving fast grind down the vanes on the water pump. Did that a couple times. A bad gasket or hole in water jacket will allow exhaust into the coolant and throw out coolant. Small bubbles may show this. Used head gasket by Best since engine rebuilder in Strasburg Pa. likes them. Hole in block will need sleeved.

[@paulzumpf3612]

I had the same issue. I replaced the cork gasket with a slightly thicker o-ring. No more coolant on the windshield. Another possible cause is loose or leaking lower hose clamps. They can allow air in and foam the coolant.

[@donaldcleveland8279]

Nice ride. Keep her going!

[@randallwingett]

Thanks, will do!

[@Bobs-Wrigles5555]

I'm a little concerned that you may have removed a bit too much coolant. For the thermometer to read correctly that cylinder on the bottom side of the cap has to be in the coolant when the engine is up to temperature. The correct way to get the right amount of coolant in the radiator is to take it for a drive and when you return open the cap(with a large rag so you don't scold yourself) and top the coolant up so that the thermometer cylinder sits in the fluid. That way you will get an accurate reading on the thermometer. If that cylinder is not in the coolant, when running, the thermometer will not work and you can overheat your engine without knowing about it. Loved the little outing, you should film more of these. Cheers from Down Under.

[@randallwingett]

Good tip! I’ll give it a try. I did pour about 8oz of coolant back into the radiator before driving it again. Thanks for the comment!

[@Bobs-Wrigles5555]

@@randallwingett Your Welcome, Just don't scold yourself when you do it. I'll also add that some old car owners modify/modernize their radiators to have an outlet pipe from the highest part of the radiator and an expansion tank beside the radiator so that you always know the radiator is full, but it does spoil the "original" appearance in the engine bay. Cheers

[@ModelARickLasCruces]

The proper level in your radiator should be just up to the top of the fins. Otherwise, the car will try to eject the extra water! And your motometer does NOT have to touch the water to measure the temperature!

[@davidheilbron4598]

The ford plaque in front of the radiator blocks 1/3 of radiator cooling capacity. Try removing it. Worked for me after trying everything else.

[@ronp.9332]

Hi Randell. thank you for you videos . I wanted a ask a question about the model A. I just messaged you on messenger , thx

[@truthreigns7]

Do you mix your coolant with water such as 50/50?

[@rodgerdoger6269]

Your timing shifting the gears is way off. You should never hear any grinding when making any shifts of the transmission like I hear in this video. Seems to me your shifting up to late of maybe not double clutching. Hate to hear gear clash.

[@andy41417]

Some guys can match speed shift. They shift slowly and can sense when to deliberately and slowly move the lever while only pressing the clutch a single time. Learned it from my dad on his ‘31 when 14. If in a rush double clutch may work and down shifting even more needed. You are throwing the lever too fast because most sticks are synchronized. The A has no syncros. Throw the lever slowly enough you can feel the mechanical resistance. Mitchell makes a rebuilt A trans with 2 & 3 synchronize. A lightened flywheel and V8 clutch pressure plate allows faster shifts into first.