JD450C Continued Cooling Problem

Coaldust · Nov 20, 2020

The Cat Bottle Test specs above are for a 10 liter engine. You can do the math and adjust it for different displacements. Or, I’ll try and find my chart from Truck Engine Analyst class way back in the day.

Heavy Chevy · Nov 20, 2020

Welder Dave said:
Check if there's water or coolant in the oil too.

Haven't seen the chocolate milk, thank God.

lantraxco · Nov 22, 2020

The 450C back when I was working on them were known for head gasket problems. And from people over-torquing the head bolts going back together, cracked blocks. The cracks occur in the web wall below the deck, so you could only find them after pulling the liners. Learned that the hard way after changing a couple gaskets after the last mechanic had already changed it a couple times and then finally sending the block in to be decked. Hope you have better luck.

Heavy Chevy · Dec 18, 2020

lantraxco said:
The 450C back when I was working on them were known for head gasket problems. And from people over-torquing the head bolts going back together, cracked blocks. The cracks occur in the web wall below the deck, so you could only find them after pulling the liners. Learned that the hard way after changing a couple gaskets after the last mechanic had already changed it a couple times and then finally sending the block in to be decked. Hope you have better luck.

Thx much, I filled the radiator with water and cranked it up....didn't see any bubbles so I'm going to try changing the water pump. An old diesel mechanic told me that he has seen it where the water pump propellers sometimes just wear down and fail to move the water like it should. I'm hoping that is my problem....crossing my fingers.

nowing75 · Dec 18, 2020

have you checked inlet and outlet temps of the radiator? Cat has a psi spec to verify if the water pump is working correctly.

Coaldust · Dec 18, 2020

Nowing75,

That’s a good point. I’ve seen many great Techs that struggle with trying to diagnose cooling system issues. Understanding the concept of heat rise across an engine block is a life-changing revelation.

No engine manufacturer that I’m aware of, other than Cat, provides those specs. To locate them in the Cat system, look in the TMI. Go to test spec data and look for “ Delta T Jacket Water ( in-out). It will
Be in the 12-14 degree range.

Coaldust · Dec 18, 2020

Simplified, check the radiator inlet and outlet temps with a infrared thermometer, while the engine is overheating. Thermostat should be open.

Should see a Delta T around 12 degrees across the radiator. This is the fun part;

if the Delta T is greater, it means a flow problem. The coolant is spending too much time in the radiator. ( bad water pump, internally plugged radiator)

If the Delta T is less than 12 degrees, it means a capacity problem. ( externally plugged radiator, radiator inadequately speced, bad shroud, fan belt slipping, air flow issue.

Summary: capacity issue or a flow issue.

Coaldust · Dec 18, 2020

Special shout out to the Caterpillar Technical Communicator & Engine Trainer at the Halton Company back in 1993 that taught me that concept during the week-long engine diagnosis class. He even put bugs in the cooling systems of a couple machines that we had to T/S overheat and overcooling conditions.

Cat even provides test ports on their engines so temp probes can be installed to monitor JW in, JW out and water mix temps. Monitor all three temps and record at 2 minute intervals during the complete thermal cycle.

Heavy Chevy · Dec 20, 2020

nowing75 said:
have you checked inlet and outlet temps of the radiator? Cat has a psi spec to verify if the water pump is working correctly.

No, I had no idea about this process.

Delmer · Dec 20, 2020

get a non contact thermometer, you can get a good one used off fleabay for $10-20, the only downside is they're not accurate on shiny bare metal, so I like to take the temperature of the painted inlet on the engine from the bottom radiator hose, and the outlet to the top of the radiator. Take these temps when the engine is as hot as you have run it, and as quick as you can safely can.

Mattjohndeere2 · Dec 22, 2020

I had the same overheating problem with my 350 - radiator was just dirty with soot from a hole in the exhaust under the hood, and a little oil, over time just built up a small layer of grime on the radiator. I really didn't think it would be the problem but after doing the water pump and seeing no difference, pressure washing the radiator fixed my overheating problem. It doesn't cost a thing and is worth a try. I do it beginning of every year now and it definitely helps.

JD450C Continued Cooling Problem

Coaldust

Senior Member

Heavy Chevy

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lantraxco

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Heavy Chevy

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nowing75

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Coaldust

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Coaldust

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Coaldust

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Heavy Chevy

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Delmer

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Mattjohndeere2

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