1973 jd440b overheating

[franksr45]

will removing the thermostat or a weak raidator cap                                 cause engine to overheat?

[snowstorm]

the t stat  slows the water down as it flows thru the block that helps it cool. rad plugges with dirt oil ect? pressure cap increases the boiling temp

[HiTech]

I have heard that old antifreeze will cause an engine to overheat. They say you should change it every so often. Not sure why this happens but maybe something in the antifreeze breaks down.

[lumberjack48]

Most motors require a thermostat to run cool, with out it the coolant flow is to fast, it flows threw the radiator to fast to cool down. Then on the other hand a lot of motors run cold with out a thermostat.
A thermostats purpose is to keep you motor at a cert-en temp. Lets say 180, the thermostat holds the coolant until the motor reaches 180, then it opens to let coolant though. As soon as it cools down it closes again, when its closed its holding the coolant in the radiator. This gives the fan a chance to cool the coolant, then opens again at 180. If its all working right it will keep the coolant at 180. If the radiator is dirtying, the fan can't draw air though it to cool the coolant and cause it to run hot [ some fans are pushers ] You have to have proper radiator cap for the system to operate right to.
Put good antifreeze in it, make sure thermostat is opening [ check on stove in pot of water ] clean radiator.
I've all so had systems air lock, make sure all the air is out of it.

The main thing, make sure the radiator shroud is on. The shroud isn't on there to protect your hands, is there to funnel the air threw the radiator.

[snowstorm]

dose it have a pusher fan? if it dose you must have the side panles with the holes in them. the rad in the 440 a or b wasnt as big as it should have been

[thumper]

when it overheats,, what does the gauge say? or is it just boiling out the overflow?

[trev]

My father has had 440 a and b's since the came in 67 . He has been working cutting and skidding since he was 18.I am saying this to say that he knows JD in and out. Having said that, he was stumped when his skidder was overheating. Checked belt, thermostat,radiator,oilcooler,water pump and hoses, but could not find the problem. the pumpshaft was rock solid an no water at the weephole so he pulled the head to find nothing wrong in there. starting back at square one he pulled the pump out and sure enough the fins were worn down quite a bit. He changed the pump and all problems were solved. It is not cost effective to change parts that are still good but sometimes the old no slack in shaft and no water at weep hole the pump is good doesn't work you still have to take the part off to check it out.

[tjdub]

I'm not sure I buy into the idea that the missing thermostat could cause overheating, but maybe.  It's easy enough to check, just put one it   It's better for the engine to have one in.

I've had overheating problems with my JD 450 dozer.  First it was because the radiator fins were half plugged.  It seems the attached transmission cooler lines had broken once upon a time.  If you have a powershift, maybe the same thing happened once,  I would inspect it.  Easy enough to clean out with the right solvent and a garden hose.  The next time was because the fan belt loosened up.  It didn't squeal or anything and the alternator still charged, just didn't keep cool when working until I adjusted the alternator.  The last time was because of a pinhole leak in the radiator.  I got it re-cored and the radiator guy used a core with a more tubes in it than the original had.  I can push like crazy now and it runs much cooler than it ever did before.

[overtime]

check the air filter my 3-53 runs warm when the air filter gets dirty same with the cat loader

[franksr45]

a friend of mine said it could be the injector timing.the engine was just rebuilt and it doesnt seem to have a lot of power

[Clam77]

First off.. Welcome to the forum Frank!!   

Injector timing will not make it overheat.. it'll just make it so it won't run right - usually either very rough or not at all.  Like has been said, removing the thermostat will just make it run cool- usually too much so.  A weak radiator cap would allow coolant to leak out and onto the ground if you didn't have an overflow canister, but if your coolant level is ok it's unlikely.

If you start the engine and let it warm up with the radiator cap off you should be able to see the coolant flowing across the fins and feel the upper radiator hose get hot once it gets hot enough to open the thermostat.  If you don't have atleast the upper hose getting hot then something is blocking flow to the radiator.. thermostat.. gasket in the wrong place after the rebuild.. air like Lumberjack mentioned..

Could even be a faulty temp sending unit..   :-\