Caterpillar C9 Engine Overheating over mountains

[2 Stroker]

My coolant was replaced when I got the new radiator and installed at Quinn Cat in California. The system was flushed and they installed Cat ECL coolant, 600k miles or 6000 Hrs. It has been 5 years so I pulled a sample and sent it in to Cat and said it was still good no Coolant Extender needed.
http://www.petersoncat.com/sites/all...ded%20Life.pdf
2 stroker

[tropical36]

Originally Posted by danny285

The coolant conditioner is a liquid conditioner that is poured into the radiator, it prevents the cylinder liners from cavitating, then burning out, and is checked at each service with a test strip along with the antifreeze

Ummmmmmm, not sure what was in it when I got it, but have purchased a gallon and added some of the recommended CAT stuff and thought that it had all that was needed for the cooling system.
I'd still like some answers to my other questions, if someone would chime in with some idea.

[W5CI]

If you purchased your coach with the CAT engine new I am sure you will never need to worry about the conditioner, I was running 125 to 150K miles per year. You guys will never run an RV that far in a life time I don't think.

[Scoob1]

You can help your engine to not build as much heat by driving it in the peak torque range. 1450-1550 rpms is your peak torque range on the c9. Manually shift the tranny to stay in this range and it should help keep your temp in an acceptable range.

[MelCraven]

We had a similar problem that continued to get worse until we took it to CAT, they changed Tstats, but said the real issue was the radiator being full of dirt. They removed the fan shrouds and steam cleaned/pressure washed the radiator and the problem went away. A few years later things were getting warm on the hills again so I cleaned out the radiator, still had the problem and found a plugged air filter. Only two years old and maybe 12k miles but we got into some powdered dirt somewhere and the filter was plugged. Sunday, so we found an air hose and blew the filter out and that got us home without any further problems.

[A Traveler]

Originally Posted by Scoob1

You can help your engine to not build as much heat by driving it in the peak torque range. 1450-1550 rpms is your peak torque range on the c9. Manually shift the tranny to stay in this range and it should help keep your temp in an acceptable range.

NO! NO! NO! Running at that relatively low RPM is a sure-fire way to CAUSE an overheat condition!

You want the engine at its peak HORSEPOWER RPM, not peak torque. That will be up around 2,000 RPM. The higher engine speed will assist in cooling because the water pump is running faster and the engine is not lugging.

It is HORSEPOWER that gets you up the grades, not torque.

[jaywolf]

I have a Cat 3126B with the 6 speed Allison I have found when towing my car trailer if I have the transmission in "Economy" mode it will overheat but If I leave it in normal mode it is fine. This may not apply to you but just thought I would ad it in case you are running in Economy mode.