Possible Radiator Problem???
 

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

Re: Possible Radiator Problem???
 

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

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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

Re: Possible Radiator Problem???
 

The motometer reads steam temp, not water.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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.

Re: Possible Radiator Problem???
 

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!

Re: Possible Radiator Problem???
 

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.