350b cooling system

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lp14255
440 crawler
440 crawler
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Joined: Mon Nov 23, 2009 6:28 pm
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350b cooling system

Post by lp14255 » Mon Mar 29, 2010 6:46 pm

i had to rebuild my water pump rescently the plastic impeller broke. i left the thermostat out of the cooling system and it runs alot cooler now, but is that bad for it. another thing is the radiator cap is rated at 7.5 lbs , the one on my dozer is 13 lbs someone else put on . after replacing with the right one 7.5lbs , it spitts out fluid after shutting the dozer off , should i put the lager one back on?

mini kahuna
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Post by mini kahuna » Mon Mar 29, 2010 9:14 pm

without a thermostat you engine will never reach operating temp.,not good for the engine,you'll use more fuel too.
I am not sure if the higher pressure cap will hurt much,someone else on here will be albe to answer that I'm sure.

KenP
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Post by KenP » Tue Mar 30, 2010 4:32 am

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lp14255
440 crawler
440 crawler
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Joined: Mon Nov 23, 2009 6:28 pm
Location: dickson,tn.

Post by lp14255 » Tue Mar 30, 2010 5:13 am

KenP wrote:Need more information before addressing your question.
All engines will run cooler without a thermostat because you've removed the flow restriction that's designed to raise the engine to the proper temp and keep it there.
Running it cold will not only affect your fuel use, but also run your oil and hyrdraulic systems cooler. Depending on the temp, that's not always a good thing.
Why did you remove the thermostat? Does the engine run hot with the normal thermostat in place? If so, you have other issues like a partially plugged radiator, bad thermostat, etc.
Proper cap is 7.5 pounds/sq inch. If you run a higher pressure cap, you'll put additional stress on the radiator, hoses, and hydraulic cooler.
All engines build temp right after you shut them off due to "heat soak". In your car, the resultant expanding fluid is caught in an overflow tank and returned to the cooling system when it cools due to differential pressure.
No such tank on your crawler, so a overfull radiator will overflow every time. Are you refilling the system every time it overflows?
When the engine is cold, the coolant level will look low, but will expand into the upper radiator tank when hot.
Are you using the proper coolant mix? This will affect coolant expansion and prevent boiling at normal operating temps.
Put the thermostat back in. Take the cap off (when cold!!) and run the engine at idle until its normalized at temp. Take the temp of the coolant and check the level in the radiator.
If the temp is normal and the top tank is about half full, you're done. Put your 7.5 psi cap on and declare victory.
i did'nt put the tstat back in cause i forgot too when i rebuilt the water pump and i full it up when its cold i guess thats why it overflows cause it has to much thanks.

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