checking model A for cracked head

They usually will lose coolant in one of two ways. The first is they will crack near an exhaust port. You can tell by either looking at the tail pipe for carbon deposits on the floor or steam when you shift going down the road. Obviously you need someone behind you when driving. Another way to check is to pull the manifold and look in the ports. Another way is that you will have a blown head gasket, usually between 1/2 or 3/4. That requires a comp. check. Mine was leaking out an ex. port and I found out from the guy behind me-and the fact the rad was stone cold after driving some distance. A can of Bars leak pellets and still no loss of coolant. There are smarter people who will chime in here but those are some things to check.

Mike
 
Just curious, wouldn't a leaky head gasket cause the symptom of losing coolant? I imagine it does not have to be a cracked head or block.
 
Pull the spark plugs and look at the top of the pistons, if one or more pistons look cleaner than the others, you probably have either a crack or a leaking head gasket.
 
1930artdeco said:
They usually will lose coolant in one of two ways. The first is they will crack near an exhaust port. You can tell by either looking at the tail pipe for carbon deposits on the floor or steam when you shift going down the road. Obviously you need someone behind you when driving. Another way to check is to pull the manifold and look in the ports. Another way is that you will have a blown head gasket, usually between 1/2 or 3/4. That requires a comp. check. Mine was leaking out an ex. port and I found out from the guy behind me-and the fact the rad was stone cold after driving some distance. A can of Bars leak pellets and still no loss of coolant. There are smarter people who will chime in here but those are some things to check.

Mike
Click to expand...

There is a third way to loose some coolant. If you fill your radiator with the
same amount of coolant each time, like a quart or so, it will kick it out through the overflow tube until it seeks the level it likes. That is the way mine does and others have said the same. Hope that is all that is happening.
:)
 
jayvee34 said:
There is a third way to loose some coolant. If you fill your radiator with the
same amount of coolant each time, like a quart or so, it will kick it out through the overflow tube until it seeks the level it likes. That is the way mine does and others have said the same. Hope that is all that is happening.
:)
Click to expand...

yup - as long as the radiator tubes are covered your good.

altho my truck with a used radiator after idiling for awhile would eventually puke its coolant out. turns out after removing the radiator, soaking in liquid plumber, then back flushing with a pool pump blasted about 1/4 can of excess water pump grease out. after that no more overheating or puking. can idle all day. all too often people pump alot of grease into the water pump and thus gets clumped together clogging the radiator tubes.
 
You can use a "Combustion Leak Test Kit" which "sniffs" the coolant to check for combustion gasses. These kits are readily available at most parts stores and are not expensive and they work.

If you have a cracked head or block or have a bad head gasket that is leaking coolant into the combustion chamber, this test will usually detect it. I have one in my shop that I use when a crack or bad head gasket is suspected.

Chris W.
 
One way without much in tools is to take off the belt and top hose fill cooling system up to within 1/4 inch of top, crank engine with ignition off and look for bubbles ---if you get bubbles --it may just raise the coolant level at first, there is a combustion chamber to coolant leak most likely you can also start the engine and see if bubbles come in the first 30 seconds or so (after a min or 2 heat may start micro boiling bubbles)
 
Did not replace any parts and just let a fresh antifreeze mix seek it's own level by letting it runout the overflow tube while I drove the car and watched the temp gauge go no higher that 185 degrees. When I parked the car I carefully removed the cap and the coolant level was 1 1/2 inches below the overflow tube and above the radiator tubes. Today I drove the car for about an hour and checked the coolant level. It did not change. I think I just have to remember what one of you mentioned, that these cars do not run full to the top like pressurized systems do and just drive the car and not keep refilling them at too high a coolant level. Appreciate all you advise and that is what is so nice about this sight.
 
ochnemowitz said:
Did not replace any parts and just let a fresh antifreeze mix seek it's own level by letting it runout the overflow tube while I drove the car and watched the temp gauge go no higher that 185 degrees. When I parked the car I carefully removed the cap and the coolant level was 1 1/2 inches below the overflow tube and above the radiator tubes. Today I drove the car for about an hour and checked the coolant level. It did not change. I think I just have to remember what one of you mentioned, that these cars do not run full to the top like pressurized systems do and just drive the car and not keep refilling them at too high a coolant level. Appreciate all you advise and that is what is so nice about this sight.
Click to expand...

yup sounds like you got it! they will find their own level.
 
There are two ways to find cracks. One is a dye penetrate. The part to be inspected is saturated with the penetrate then wiped clean. A powder is applied that sucks the penetrate out of the cracks. Viewing under a UV light will show the cracks.

The other is with iron powder and a magnet. The magnet is put in contact over a suspected crack and any iron powder will stick along the crack where the magnetic flux is forced to the surface. This method only works with cast iron or steel parts.

A good shop should have both methods.
 
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