Roofing nail in overflow tube

[SuperDave]

Beware ! I tried that. Never again.
1930 with the quail cap. I didn't realize the system became pressurized. Upon turning the quail to check coolant level, It erupted, sending scalding water into the rafters! Not to mention part of my body! Maybe with the original cap, the pressure would bleed off upon the first portion of cap removal? The quail is either closed or open.

[JDupuis]

SuperDave; were you losing alot of water before putting the roofing nail in?
May be time for a good rad flushing. Jeff

[Benson]

...

[BILL WILLIAMSON]

The nail is a "fix" for an otherwise "normal" operating system. Make sure the nail fits LOOSELY, in the overflow tube.
Bill W.

[katy]

Maybe one needs to cut or file a notch in the top of the overflow tube, before inserting the nail. That way there is always a small opening to prevent pressure build up.

[eagle]

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Originally Posted by katy

Maybe one needs to cut or file a notch in the top of the overflow tube, before inserting the nail. That way there is always a small opening to prevent pressure build up.

Or give the nailhead a little tweak. I don't have anything in mine and I have no problem, so I agree its not necessary in all radiators.

[glenn in camino]

I too tried that many years ago, and the pressure ballooned the radiator tanks running the radiator.

[RawhideKid]

If you folk would take the time to read the Service Bulletins, p450, Henry knew he had a problem with the water pump forcing water out the overflow tube when it was assembled with the overflow tube top in the forward position and with the repositioning of the tube tucked under the lip in the rear of the filler area resolved this issue. He also began a new style of baffle to divert the excess flow away from the filler neck.

For those who have this splash issue, you need to look down into the radiator top and see if you can see the tube tops, if you can, if you remove the cap and start the engine, you will see exactly how the pump shoves water over the top of the overflow tube, and need to reposition the tube top to the rear of the filler neck. and I would place a piece of tubing inside the overflow tube and bring the height up as high as you can into the filler neck.

[H. L. Chauvin]

Lots of times Model A recommendations can become dangerous because of who will be following the recommendation; like,

1. Just remove your rear spring ..... boing .... the Model A Forum guy who tried this only had to go get his nose in his neighbor's yard.

2. How about Victor Page's recommendation to clean a Model A radiator with Lye ..... this guy's wedding ring came off .... with his ring finger.

3. Close and open ignition points to see if the coil wire sparks ....... this guy ruined his underwear and trousers when he got shocked ...... with one suit, he missed Sunday church.

4. Crank your Model A when the battery is low ...... he missed his next hunting trip because he could not pump his pump shot gun with one arm in a sling.

5. This over flow nail trick is as old as exploding rear springs, commercially peeling tons of sweet potatoes for canning with Lye, checking opening points with a non-electrical conducting wood handle screw driver, and making sure the Model A spark is far retarded prior to cranking.

6. A loose nail ..... nail knowledge ....... can anyone imagine results on advising today's Model A Forum members on how to nail steel horse shoes on their new horses with horse shoe nails.

[Gold Digger]

I'm with #5. Several years ago I had the problem of losing water out the overflow and heard about the nail thing. Knowing how it could seal off like a valve, I filed a notch in the top edge of the overflow pipe and never have had another problem in 5 years with this radiator. Another car I have has never given a problem and I never have had to put a nail in it.

[H. L. Chauvin]

My original radiator has no radiator baffle and the radiator overflow tube was low; e. g., about one (1) inch above the radiator tubes.

Ten (10) years ago I slipped a rubber hose over the low metal radiator overflow tube and allowed this rubber tube to extend upwards to within about 3/8" below the top rim of the radiator filler neck.

Inserted a small diameter nail, (about 1/2 the diameter of the rubber tube), with a large diameter head, (which completely covers rubber hose opening), and all works well.

The upper radiator hose has a stainless steel laundry filter fitted in an additional rubber hose to catch rust particles from the block.

The radiator coolant never exceeds 175 degrees F in 100 degree ambient temperature; hence, never any steam pressure.

Maybe I am missing something, but, as stated in Reply #4 above, this nail will work in a "normal" radiator:

A. With "clean" filtered coolant that cannot clog a metal radiator overflow tube; and,

B. in a "normal" radiator that can never boil coolant if the coolant remains at a "normal" level.

Moral of this Story appears to be: "

If your "abnormal" Model A radiator overheats and boils coolant, you cannot fix it with a nail!

Might Add: Also, if your Model A gas tank leaks, do NOT try drilling a large hole in the bottom of your gas tank, and fill this large hole with a small diameter shank nail with a large diameter head ....... i.e., again, you cannot fix it with a nail!

[BILL WILLIAMSON]

Also, make SURE the overflow's not PLUGGED! They're often plugged by Mud Daubers & here, we have Leaf Rollers, that plug them also! An old speedo cable cleans them well.
If your overflow dribbles & causes ugly rusty crap on your spring, just add 6 or 8" of hose to it. Handy to have short hose scraps! At my parts store, I ask, "Let me see your box of hose scraps"---Then I buy the WHOLE box full!!
Rev your engine & observe the WILD water flow, small wonder we sometimes get "splash" over into the overflow & BIT by BIT, we get LOW on water!
On Minerva, I added a BIG OLD Moto-Meter, with a BIG, LONG probe, then she began to lose water!!! I revved her up & "simulated" the probe with a FAT bolt & discovered it caused a TURBULANCE, that was dumping water out the overflow! Added a LOOSE fitting roofing nail & cured that problem.
SORRY for the LOOOONG Harrangue, but we all need READING practice--LOL
Bill Cool

[Bob Bidonde]

Rather than using a nail, I use an orifice made by drilling a hole through a stainless steel bolt. The orifice reduces a pressure increase and minimizes coolant loss through the overflow. Make the orifice hole 0.09" Diameter (#10 or 3/32 Drill).

[Y-Blockhead]

You could try using a large headed Pop Rivet with the 'stem' removed to cut down the oriface size and shield the over flow tube. just a thought, I need neither.

[BILL WILLIAMSON]

Originally Posted by Bob Bidonde

Rather than using a nail, I use an orifice made by drilling a hole through a stainless steel bolt. The orifice reduces a pressure increase and minimizes coolant loss through the overflow. Make the orifice hole 0.09" Diameter (#10 or 3/32 Drill).

TRICK idea, Bob
Bill W.