Pushing Coolant Out The Overflow

M

mollydog

Member
I am having a problem with coolant being pushed out the overflow tube. I've tried the "Nail" and extended the overflow tube in the Rad. I loose about 2 quarts of water in a 40-50 mile run. The engine does not seem to get hot or overheat. I've heard the waterpump pushes out to much water for the rad to handle. The rad is in good condition, the whole system has been flushed and the water runs clear. No oil in the water and the compression is good. (Miller Hi-Speed Head).
I've heard drilling a 3/16" hole in the pump impeller blades OR Radius the corners to cut down on flow. Which do you feel is best? The pump has a four blade impeller and does not leak. I know there is another post about overheating but that doesn't seem to be a problem. Suggestions?

Mollydog
 
I have same symptons with my A .. The difference between you & I is that my A is pressurized.
Anxious to hear of solution...

Rog
 
Molly,

Mine does the same thing. But what I noticed is that my rad tubes are about half the size of the originals. So I bought-have yet to install though-a thermostat that goes in the upper hose. I got it more just to slow the water down so that it has time to go through the tubes.

And just to make sure, I will clean out the rad by back flushing and anything else I can do just to make sure everything is clean.

Mike
 
Most A's will dump coolant until the tubes are just covered(about 3/8") and then stabilize--have you tried that?
 
I had a similar problem because my radiator cap was not closing properly. I eventually found that the radiator cover was mounted at a small angle and this caused the radiator cap to only hold on 1 of the two nipples.
 
jetrod said:
Most A's will dump coolant until the tubes are just covered(about 3/8") and then stabilize-
Click to expand...


I read that here on FB all the time. However, it has been my experience that only with the old (original) radiator, that was true. The old radiator was not what I would call "blocked", but it certainly was restricted. Installed a new show quality radiator and it's just the opposite. Now, the radiator stays exactly where it is supposed to be, just below the overflow tube almost exactly at the baffle. That is at least an inch or two above the tubes. Never have trouble with coolant coming out the overflow now, regardless of how hot it is outside or how high the motor revs.

Investigation of the old radiator showed what appears to be grease lining all the tubes and causing them to have poor flow. Sorta like clogged arteries.
 
The impeller has FOUR blades, not three. I have it out and am looking at it right now. I have flushed and back flushed the radiator and the block twice. The radiator was re-cored before I bought the car. I do not have a thermostat in the upper hose. I ordered one and hope that helps out. Any input on modifying the impeller?

Mollydog
 
How do you know it takes 2 quarts after a 40-50 mile trip? If that's how much it takes to fill the radiator then it's acting normally and don't put that 2 quarts back in. When full the cooling system holds 3 gallons. When up to normal operating temperature the coolant will expand by 1/2 gallon. If you don't replace the 1/2 gallon that goes out the overflow from expansion the system, when cold, will contain 2 1/2 gallons and when it gets up to temp the system will be full again. That's the way they are designed - to seek their own level.
 
That's good information Larry. Maybe that is why I'm not experiencing overheating problems. I always thought the coolant level should be at least at the baffle when cold. When this radiator is cold it is not covering the top of the tubes! I'll install a thermostat and hopefully that will cure my perceived problem.

Mollydog
 
Does anyone know why my water pump impeller has FOUR veins instead of three??? Everything I can fine on the "A" water pump shows three veins. Where would a four blade impeller come from?? Would the four blades pump more water and thus Too much??

Mollydog
 
I had the same problem last year, and actually blew a motor due to reduced coolant in the system. I installed the upper hose 160 degree thermostat that Snyder's sells, and installed a temp gauge as well. I now experience quicker warmup, and the temp gauge rarely moves higher than 160 no matter what speed I run. I had a few stretches of 50mph on the ride down to the Old Car Fest and watched the temp closely, everything worked beautifully. My coolant level is just a bit higher that the tops of the cooling tubes as others have mentioned and has been that way for a full year of driving with no added coolant.
 
Early '28's had a 4 vane impeller's. They also had fan shrouds. Maybe you have one of those early 4 vane water pumps.

Ford found the engines were running too cold so reduced the vane count to 3 during '28 production. Same thing with the fan shroud. The didn't need it and they could save a few bucks. That deletion was in early 1929 production.
 
Thank you Richard. I thought I was going nuts with the four vane impeller. I think I'll order a rebuild kit with the three blade impeller. Thanks again.

Mollydog
 
Three blade impeller rebuild sounds good to start.

Do you have a new style cored radiator, or the original style.

The thermostat, if you decide to install, is available in a 160 or 180 degree.
 
I would recommend buying the impeller with the stainless steel shaft installed and pinned. I was pressing an original impeller onto a new shaft when the cast impeeler exploded. Pieces were scatter around the garage, and I was lucky a piece didn't hit me in the face or take out an eye. BTW last week my nephews were rough housing and the 7 year old hit the 5 year old in the eye with a belt buckle. A few visits to the hospital have already cost my brother over $10,000. That could have bought a nice antique car.
 
I had a similar problem and discovered two issues. The overflow tube had a hole in it due to corrosion, inside the upper tank where you couldn't see it. When the fluid level expanded above the core, is leaked out. My radiator also didn't have a baffle in it. I replaced the tube and had a baffle installed, problem was resolved.
 
Bergy, Thanks, I'll check for the same problem. I did put in in a thermostat and drilled the impeller vanes with a 3/16" hole and put a radius on them. It rained all day today so I couldn't take it for a test. I hope to give it a good run tomorrow. I'll let you know how it goes.

Mollydog
 
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