Possible Radiator Problem???

[loubob]

While driving my car to our annual September car show I have to drive up several hills.
I've driven this route many times with no problems.
This day the car started "spitting" antifreeze out the radiator cap on 2 of the hills. Not a lot but enough to concern me. The 2 hills were about 5 miles apart.
Drove home a different way, flat roads, no problem.


Took the car out a week later and intentionally drove up several steep hills to see if the problem was still there.
First hill was almost at the top and antifreeze started coming out the cap.
The second hill was about 7 miles down the road and very steep from the start. NO problem-NO overflow.
Car has 160 degree thermostat.


Drained radiator today and removed thermostat.
Plan to flush system later this week using a radiator flush.


Looking for thoughts/suggestions. I plan to install new 160 'stat.


Thanks….Bob

[noboD]

SO what did your infrared temperature scanner say? All four corners of the radiator?

[Big hammer]

47 years ago when I was a new bee, I would keep topping the radiator and it would sometimes overflow. When I let it seek its own level it quit overflowing. Also check the cap gasket, it should not leak there, it should come out of the overflow tube. You are adjusting the timing, retarding when climbing hills a little but not to much.

[DHZIEMAN]

It has been my experience that Model A Ford Radiators find their own natural fluid level. Keep a monitor on your temp and before going on another test, do a fluid level check of the fluid in the upper tank. If there is about an inch or so, do not refill. Rerun your test. And Make sure the GAV is properly set and the advance is properly set. If it is still blowing out liquid, then I would start looking at the need to fix something.

[rocket1]

I don't understand the statement leaking out of the radiator cap,they cap should be tightly sealed to the radiator,leak would be out the overflow to the ground.

[The Master Cylinder]

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A couple of months ago my radiator did something similar while driving around in the hills. When I got back to the house there was some coolant splashed around, presumable from coming out of the radiator cap and hitting the fan. I checked the water level while the engine was idling and it appeared foamy. Because of the foam, the first thing I thought of was to check the head torque and sure enough I found a few loose. Retorqued the head and all was good.
Not saying this is your problem but it is a easy check.

[Jacksonlll]

Your radiator is plugged. It should flow at least 36 GPM.

[30 Closed Cab PU]

If flushing - suggest initially flush/backflush motor and radiator separately with water, catch the water in a big tub so you can see what comes out. Then do same with whatever chemical method you were going to use chemical (thermocure, Rust 911, commercial, white vinegar, etc.), If using something acidic/aggressive, flush with baking soda mix to neutralize. Then install an upper hose coolant filter and run.

[sethkestenbaum]

If you run it with some vinegar or anything designed to loosen up pieces of rust/gunk, you might want to RUN THE CAR WITH A FILTER IN PLACE. You don't want flushed rust/gunk to be circulating into the radiator only to clog something else up.

[TJMack]

Originally Posted by DHZIEMAN

It has been my experience that Model A Ford Radiators find their own natural fluid level. .

My limited experience tends to agree with this. I just got a sedan that has a Motometer on it and I'm wondering how that is going to work unless the coolant level in the radiator stays within about an inch of the top. I haven't driven the car enough yet to know if it works at all.

[loubob]

Car has motometer cap.
Fluid was just above the fins.
The antifreeze was actually bubbling out around the cap.
Going to flush system Friday, as temp is supposed to be 50.
Cannot remember the exact infared temps but positive the upper radiator was in 170's to possibly low 180's. Lower temps 35-40 degrees cooler.
I will change rad. cap gasket tomorrow.

[ryanheacox]

I would suggest checking the head torque if the flush doesn't work.

[loubob]

TMC: I will check torque.
Jackson:I don't think my rad. has ever come close to 36 gpm but it's run fine for the
6 years I've owned it.
TJ: Coolant should be just covering the fins.


Thanks to all the rest. Will advise what happens.

[loubob]

DHZIEMAN: Where should the gav be set? Rich? Lean?

[whirnot]

Originally Posted by TJMack

My limited experience tends to agree with this. I just got a sedan that has a Motometer on it and I'm wondering how that is going to work unless the coolant level in the radiator stays within about an inch of the top. I haven't driven the car enough yet to know if it works at all.

The motometer reads steam temp, not water.

[whirnot]

I had similar problems and a new radiator didn't solve it. I finally put a clamp on the upper radiator hose so it the thermostat wouldn't work its way to the top, and let the level of the coolant fall a little. As long as it's above the tubes, should be fine. I think the thermostat at the top of the hose was creating too much turbulance.

[Synchro909]

If coolant is coming out from under the cap, the overflow must be blocked. That will not be the cause of your troubles but worth looking at (and correcting) anyway.

[30 Closed Cab PU]

Worst case is head gasket is going, and only apparent when car is under load (hills).
Could try as mentioned re-torqueing Head, checking the overflow is open, flush backflush, run it and see if now OK. . Then compression/leak down, or Napa Block Test kit that measures exhaust gas in the coolant. Mechanic or radiator shop may also be able to test for the coolant test.


Since you have had the car for awhile, I'm sure you know what is normal for your car, and something has changed. Would not think it would be GAV setting, coolant level, etc - seems you would already know that stuff.

[DHZIEMAN]

Originally Posted by The Master Cylinder

A couple of months ago my radiator did something similar while driving around in the hills. When I got back to the house there was some coolant splashed around, presumable from coming out of the radiator cap and hitting the fan. I checked the water level while the engine was idling and it appeared foamy. Because of the foam, the first thing I thought of was to check the head torque and sure enough I found a few loose. Retorqued the head and all was good.
Not saying this is your problem but it is a easy check.

Master Cylinder makes an excellent suggestion, If you are not familiar with the method of retorquing, here is what I had been taught and then forgot, and a Forum member refreshed my memory. To retorque a Model A Head, the first step is to loosen (using the model A Ford tightening bolt pattern) and then Re-tighten to the correct Ft/lbs! And for the one nut next to the distributor, use a crows wrench to prevent having to remove the distributor. You will find that if you have a loose nut that this re-torquing method will crank the nut down more than it has been loosened.
What I discovered on my model A was, all nuts wound up needing re-torquing!

[DC 69]

Are gas caps the same size as radiator caps? Is it posible to put a gas cap on a radiator?

I was driving on a pretty warm day, up & down a few hills, when antifreeze came out from cap because temp was over 200*F. Stopped to let the car cool down & all was fine after.

Gasket is good, but I was wondering if I had a vented gas cap on my radiator.

[abachman3]

Understanding that previously there was not an issue climbing these hills, there has recently been discussion here on the Barn about retarding the spark some when climbing hills. Perhaps this is an occasion where that would be prudent.

[Bill G]

Originally Posted by DC 69

Are gas caps the same size as radiator caps? Is it posible to put a gas cap on a radiator?

I was driving on a pretty warm day, up & down a few hills, when antifreeze came out from cap because temp was over 200*F. Stopped to let the car cool down & all was fine after.

Gasket is good, but I was wondering if I had a vented gas cap on my radiator.

28-29 caps are both threaded and are, indeed, identical except for one is vented and the other is solid. I am not sure about 30/31 twist-on's. When I first got my car, someone had reversed mine. Radiator was loosing water from the cap itself. The cap on the gas tank was drilled with a hole and a small nut & bolt inserted. This created a vent, of sorts.

It should be noted that if you use a radiator cap on the gas tank, there is not normally a vent. All things being equal, your car won't run very long because the lack of a vent will create a vacuum in the tank, and you would have to get out and open the cap to let it vent before going on your way.

[George Miller]

head gasket, or slow timing, or to lean a mixture will do it.

[loubob]

I am going to do a radiator flow test this Friday. Results will determine if I take the radiator out now or wait till Spring and see if my use of spark/gav is incorrect.
Thanks again for your responses.
Bob

[pinball73]

Guys I had the same problem ! i took the radiator to a radiator shop & bad it boiled out & repaired, but it did no god. they were afraid to try to rod it out for fear of destroying it. I put it back on the car & had the same problem all over again! would loose coolant on a long hill or a hot day. turned out that the radiator was about half plugged & the water pump was just simply moving more water than the radiator could handle. I broke down & bought a new aluminum radiator & problem solved.

[noboD]

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Why wouldn't you have it rodded out? If it was already junk they couldn't ruin it, only fix it.

[Synchro909]

Originally Posted by pinball73

Guys I had the same problem ! i took the radiator to a radiator shop & bad it boiled out & repaired, but it did no god. they were afraid to try to rod it out for fear of destroying it. I put it back on the car & had the same problem all over again! would loose coolant on a long hill or a hot day. turned out that the radiator was about half plugged & the water pump was just simply moving more water than the radiator could handle. I broke down & bought a new aluminum radiator & problem solved.

I'm afraid this is a common myth. It is not possible for the pump to move more water than the radiator can handle because the ONLY place the pump can get water is from the bottom of the radiator (via the engine) I suspect that when your radiator was tossing coolant out, the coolant was boiling, thus increasing its volume.
Whatever, it is fixed now so enjoy.

[30 Closed Cab PU]

Originally Posted by Synchro909

I'm afraid this is a common myth. It is not possible for the pump to move more water than the radiator can handle because the ONLY place the pump can get water is from the bottom of the radiator (via the engine) I suspect that when your radiator was tossing coolant out, the coolant was boiling, thus increasing its volume.
Whatever, it is fixed now so enjoy.

Not agreeing, not disagreeing, just need more explanation.


1.5 gals in the radiator, 1.5 gals in the motor/hoses. If the water pump pumps more water than can flow through the radiator, why can the pump not continue to pump/draw the 1.5 gals from the block causing pressure, pumping water out the overflow and/or an ill sealed radiator cap?


Agree that it could be boiling. Overheating coolant caused by head gasket leak into coolant raising the coolant temp. Is it also possible a bad head gasket cylinder leak to the coolant passages cause the pistons to add pressure into the coolant?

[Synchro909]

Originally Posted by 30 Closed Cab PU

Not agreeing, not disagreeing, just need more explanation.


1.5 gals in the radiator, 1.5 gals in the motor/hoses. If the water pump pumps more water than can flow through the radiator, why can the pump not continue to pump/draw the 1.5 gals from the block causing pressure, pumping water out the overflow and/or an ill sealed radiator cap?

Closed Cab, Let me try to answer that question by asking another: What is going to replace the water taken from the block?

[eagle]

Originally Posted by Synchro909

Closed Cab, Let me try to answer that question by asking another: What is going to replace the water taken from the block?

Exactly. When the radiator is partially plugged, the lowest pressure of the whole system is in the engine block. Lower pressure = lower boiling point = coolant flashing to steam = expansion of flashed coolant by 1700 times the volume = coolant pushing out anywhere it can. Fix the radiator, fix the problem. Reduce the water pump volume = bandaid fix that may get you by but not indefinitely.

[30 Closed Cab PU]

Originally Posted by Synchro909

Closed Cab, Let me try to answer that question by asking another: What is going to replace the water taken from the block?

Thanks for your response, excellent question. I had to think about this overnight and think I have come up with a proposed theory/explanation that works for me. What was confusing for me is the A cooling system is a closed loop, but not totally sealed system (overflow tube).


Flow is restricted via a clogged radiator. The pump works harder trying to draw more coolant out of the block and pumping/pushing it into the top of the radiator. This would create pressure in the top of the radiator, lower pressure in the bottom of the radiator.


My aha moment was when I realized the Model A water pump is low pressure vane style pump? The vanes do not have the feature of vane seals to the impeller cavity to create higher pressure. When the system has a clogged or partial clogged radiator more water water slips(leaks) past the vanes. If true the vanes can not create significant pressure to try to overcome the restriction caused by a blocked/partially blocked radiator.


Wada youall think? Does this make sense, partial sense, or am I crazy?
Perhaps all?

[30 Closed Cab PU]

Originally Posted by eagle

Exactly. When the radiator is partially plugged, the lowest pressure of the whole system is in the engine block. Lower pressure = lower boiling point = coolant flashing to steam = expansion of flashed coolant by 1700 times the volume = coolant pushing out anywhere it can. Fix the radiator, fix the problem. Reduce the water pump volume = bandaid fix that may get you by but not indefinitely.

X2


Agree, good info. Fix right, band aids OK to get you home. Band-Aids have a tendency to fail at inopportune times. 100 miles from home, on a day tour, out in the middle of nowhere, etc. Plus it is always a worry, about wondering if the Band-Aid will hold.

[ryanheacox]

Originally Posted by eagle

Exactly. When the radiator is partially plugged, the lowest pressure of the whole system is in the engine block. Lower pressure = lower boiling point = coolant flashing to steam = expansion of flashed coolant by 1700 times the volume = coolant pushing out anywhere it can. Fix the radiator, fix the problem. Reduce the water pump volume = bandaid fix that may get you by but not indefinitely.

Yep, and the lowest pressure of all is going to be in the head... right where you need it most. Does anybody know why Henry thought a pull through cooling system was better?

[Synchro909]

Originally Posted by ryanheacox

Yep, and the lowest pressure of all is going to be in the head... right where you need it most. Does anybody know why Henry thought a pull through cooling system was better?

In only two words: "It's cheaper."
The option is a "Push Through" system where the water pump is between the bottom of the radiator and the block. It is not so easy to put the pump down there for the same $.
All that said, the Model A water pump doesn't create any pressure to speak of. It can, however, move a large volume. I doubt it is capable of causing a low enough pressure in the block/head to lower the boiling temperature much at all. If the SLIGHLY lower pressure were enough to do that, the system is @#$%ed anyway.
Remember, the Model A cooling system can best be described as "pump assisted thermosyphon". With a good radiator, you can drive without the pump - I've seen it done by a club member on a 1,500 miles drive.

[loubob]

pinball73--I did the same thing shortly after getting my car. Rad. guy had a great reputation. Cleaned tanks, would not rod out the tubes, and repaired the several small leaks as best he could.
If the "in car" test tomorrow fails, out it comes. Will get it checked and go from there.

[Jacksonlll]

Last summer our club set up a way to flow test a radiator in the car. It takes a bigger pump than we had, have a bigger one now, but we were able to identify a plugged radiator easily. 36 GPM is a lot of water. More than my old sump pump could do. Will do more on this, this summer. Our member heading this effort, Dave has got the set up figured out.

[Jacksonlll]

I did a test last summer on my car that has a good radiator. I ran the engine at about 2300 rpm. I think that is the engine speed for about 45 MPH. I put a pressure tap in the lower hose, expecting to see a lower pressure there at the higher RPM, but got absolutely no difference, meaning that the radiator was easily flowing at a high rate and that the pump was not causing any, measurable, lower pressure in the engine. With a plugged radiator, I still think I would have seen a lower pressure down at the lower hose. Will have to find a car with a plugged core to test again.

[30 Closed Cab PU]

Originally Posted by loubob

DHZIEMAN: Where should the gav be set? Rich? Lean?

Rereading this string, looks like this was not answered. Plus am summarizing what may be happening.


A good starting point is to read the recommendations in the Model A Owners Manual. There should be a free download available on line if you do not have one. If you can not find it, ask here, someone probably has the link.


Depending on the car, adjustment of GAV and Spark Lever varies. Depends on the condition/wear of the car, and how the base settings are adjusted/calibrated.


At speed, with engine warm, under load (hills) GAV should not be set too lean, can make engine run hot. Usually should not be set less than 1/8 to 1/4 quarter turn open. If the spark is set retarded (lever up), and the GAV is not set correctly, motor can backfire, especially at low speeds.


Spark lever under same conditions should not be either over advanced lever down) or overly retarded (lever up). The tendency is to run with the lever fully advanced (lever down) on hills since it gives you the most power, but this is not good on the motor.


A rule of thumb is to set the Spark level to match your speed when adjusting the lever, half speed/half advance, full speed/full advance, idle-very slow speed/not full retard but a few notches down on the lever. Lever full up retarded, only when starting and once motor pops/runs set down a few notches. At idle it is ok for a very short time to run full retard, not really great for the motor, and causes motor to heat up, amongst other things.


For your issue your having, try the same route repeatedly, and try different settings each time. Write down the results.


What would be very helpful is if you had a coolant temp gauge, the type where the sensor is in the head upper coolant neck, with a gauge inside your A. Makes it easier to diagnose, and handy to keep track of Temp if a problem is about to occur. Moto meters give you a rough view , I find a temp gauge a lot more useful.


I suspect your issues are not GAV/Spark setting related. However these are easy things try and rule out in the progression of trouble shooting cooling issues. IMO these may help, but are not the real cause of the problems. Cooling issues are; marginal/bad radiator, bad head gasket, excessive buildup of rust/scale in the cooling passages in the head/block.


My opinions based on my dealing with cooling issues, opinions may vary.

[30 Closed Cab PU]

Another string currently running on settings.
https://www.fordbarn.com/forum/showthread.php?t=256005

Originally Posted by 30 Closed Cab PU

Rereading this string, looks like this was not answered. Plus am summarizing what may be happening.


A good starting point is to read the recommendations in the Model A Owners Manual. There should be a free download available on line if you do not have one. If you can not find it, ask here, someone probably has the link.


Depending on the car, adjustment of GAV and Spark Lever varies. Depends on the condition/wear of the car, and how the base settings are adjusted/calibrated.


At speed, with engine warm, under load (hills) GAV should not be set too lean, can make engine run hot. Usually should not be set less than 1/8 to 1/4 quarter turn open. If the spark is set retarded (lever up), and the GAV is not set correctly, motor can backfire, especially at low speeds.


Spark lever under same conditions should not be either over advanced lever down) or overly retarded (lever up). The tendency is to run with the lever fully advanced (lever down) on hills since it gives you the most power, but this is not good on the motor.


A rule of thumb is to set the Spark level to match your speed when adjusting the lever, half speed/half advance, full speed/full advance, idle-very slow speed/not full retard but a few notches down on the lever. Lever full up retarded, only when starting and once motor pops/runs set down a few notches. At idle it is ok for a very short time to run full retard, not really great for the motor, and causes motor to heat up, amongst other things.


For your issue your having, try the same route repeatedly, and try different settings each time. Write down the results.


What would be very helpful is if you had a coolant temp gauge, the type where the sensor is in the head upper coolant neck, with a gauge inside your A. Makes it easier to diagnose, and handy to keep track of Temp if a problem is about to occur. Moto meters give you a rough view , I find a temp gauge a lot more useful.


I suspect your issues are not GAV/Spark setting related. However these are easy things try and rule out in the progression of trouble shooting cooling issues. IMO these may help, but are not the real cause of the problems. Cooling issues are; marginal/bad radiator, bad head gasket, excessive buildup of rust/scale in the cooling passages in the head/block.


My opinions based on my dealing with cooling issues, opinions may vary.

[TerryH]

I had some overheating issues with my A about 13 years ago, and our Tom Endy suggested I have the radiator rodded. I took it to an older gentlemen who knew how to do it, and he found that over 20 tubes were totally or partially clogged. He was able to open all but a few of them, and my car has never overheated again. Rodding can work if it is done by someone who knows what they are doing, and can open clogged tubes that other methods cannot.

[loubob]

Stationary test did not go as planned. So, it's coming out and will be tested by a long time radiator guy IF I can get ahold of him.
I now seem to remember the first radiator guy cleaned the tanks but no rodding as he was afraid he would destroy the radiator.

[30 Closed Cab PU]

Sometimes rodding and testing is not enough, they just plain get worn/aged out, loose fins and poor fin connection to the tubes. If you end up painting the old, do not apply a thick coat, just enough to cover. Thick paint affects dissipation/transference of heat to air. Some Barners










have been through the process of radiator flush/backflush/rodding, and either have had to replace the core or replaced the radiator.

[Jacksonlll]

Syncro, very well said. Sound like you understand IT.