This Friday, I will be making about a 60 mile trip in my 53. This will be the longest trip I have taken with it so far, and will be probably averaging about 45 mph the whole way.

I am a little worried about overheating and I am hoping some of you can calm my concerns. My temperature gauge in the truck does not appear to be accurate. Sometimes, it reads all the way to Hot immediately upon starting up even though the temps here have been about 30-40 degrees. Sometimes it stays about in the middle. Another concern is that almost every time I drive the truck, I get a little bit of radiator fluid that drips out of the overflow from the radiator. The oil breather cap also smokes a small amount as well when you turn the engine off after it has been running for some time.

Those are basically what concerns me. Are there any very obvious signs of overheating in these old trucks?

I know the gauge could just be bad or badly wired, the oil breather cap smoke and the radiator overflow drip could also be normal.

Thoughts or concerns?

 

Jim

Have you checked / replaced the thermostat? You shouldn't be getting overflow on every drive unless you are way overfilled.

The breather cap smoke is a feature - nothing to worry about there.

DW

 

I have not replaced or checked the thermostat. How would I check it? Also, The radiator is pretty full...when I take the cap off and it is cold, I could easily put my finger in about an inch or two and touch fluid. Is this too full?

 

Drive it several times, let it puke coolant 'till it seeks the level it will stay. Keep a close eye on it. Coolant level should remain above the cores. An infrared thermometer is a very easy way to keep tabs on your temperatures.

 

You'll find thermostats at the intersection of the engine block and the upper radiator hose(s). Some POs have been known to simply remove them. They can also stop working properly all on their own over time.

 

If you have the stock radiator, which is not real likely, there was a tab soldered in the tank under the filler neck to indicate full level (cold). It's at least an inch down. There are 22 quarts of fluid in the system, that expands quite a bit.

You have two thermostats to check, one for each bank. Use 180's or 190's, not 160's. Your radiator cap needs to be a 4 psi cap, available at NAPA. A more common 12 or 13 psi cap has the potential to split your tanks.

 

An easy check of the thermostat can be done by inserting a thermometer into the radiator and running the truck until the thermostat opens. Start with the radiator cap off, you don't want to remove it once the system gets warm and is pressurized. You can tell when the thermostats open, the water will increase in temperature pretty quickly. The water in the radiator won't get up to temp as soon as the thermostats open it should in a fairly short time.You can also remove the thermostats and put them in a pan of water, again, with a thermostat, heat the water and watch the thermometer. When the water reaches the thermostats' opening temperature you hear them pop.

My suggestion to you is to install mechanical temperature gages. I have two, one for each side of the engine. I installed mine because I was getting a false over temp within five minutes of starting the engine. I did everything to cooling system I could think of and the gages always pegged overtemp.

 

I routinely check all my cars with an infrared thermometer when hot, tells you if the temp gauge is right or not. A mechanical temp gauge is also a good idea.

 

The breather cap smoke is a feature - nothing to worry about there.....

what do you mean by that DW? Curious because mine does the same. Thanks!

 

The smoke is blow by. The sloppier the engine gets, the more smoke you see. No PCVs on these old engine so the crankcase fumes come out. Make sure the road draft tube and the oil filler cap are clean.

 

take it from me you'll know when she's boiling over !!!! i drive my 52 customline daily now , and when my 53 was in one piece it also was beaten on and abused daily . they both got flatties . the 52 just had the bottom hose's collapse and cause her to boil over . i have had several new thermostats freeze up and not open so i took the advice of some and removed the center part of them leaving the outer rim as a sort of restriction to slow the coolant flow down a little and have had no problems at all . in both of mines cases and even with this last time , i have flushed them out best i can and still keep getting all kinds of casting sand and garbage out of 'em as ford didn't do a ral good job at getting them cleaned out at the factory !!!! they , with the oe pumps as mine have , but not for much longer i hope , cannot have the belts tightened up real snug as they wear the pumps bearings etc. out quickly . so you leave 'em a little loose and you can have minor issues like not charging properly , and possibly running warmer than expected according to those who know , and in my personal experience if i push the 52 more than 55 -60 mph . modern pumps should solve this i hope !!! but don't believe anyone when thery say they aren't dependable , even me when i get angry at one of them cause it decided to give me crap that day and i start ranting about obsolete dinosaurs ............

 

If you use the old thermostats make sure that they are the same temp. Mine had a 160 and a 180. Of course they were in the glove box but still . . . Some PO had run it like that.

They should be marked somewhere near the sealing surface.

 

Looks like you got some good info, I don't think you have an overheating problem but one more thing to check is the suction hoses from the radiator bottom to the pumps. If old or wire is gone walls may be sucked in at higher speeds.

 

The simplest way to check and see if the thermostats are opening and when is touch or hold the upper radiator hose from each side. The flatheads are totally separate engine halves. The water from the left side of the block and the right side are not internally connected inside the engine.
When the thermostats open the upper hose will suddenly get very warm and it is very rare for both thermostats to open at exactly the same time. If the engine is getting very overheated you will not be able to hold onto the hoses very long. At 160 degrees they are pretty warm to the touch, 180 you can hold them for several seconds but it gets uncomfortable. Much warmer than 200 they get hard to hold more than a few seconds.
Good Luck
Larry

 

I have the exact same problem. My gauge calibration might be a function of switching to 12 volts but it runs on 'H' a lot and only sometimes goes down to 1/2. What I noticed is that it stays on 'H' until the thermostats open...when they do, you can see the gauge respond and move down. I'm planning on putting in mechanical gauges but for the moment I know it's not running hot at all so I haven't worried about it.

I installed these

Mustangsplus.com | Mustang Parts :: Cooling - Radiators & Fans :: Gano Inline Radiator Filters :: 1965-73 Gano Clear Plastic Radiator Filter - Medium

to filter out the crud and you can actually see the water flow when the thermostats kick in. They are expensive, but cheaper than a clogged radiator!

Ryan