Cat C7 Engine: ELC Coolant or Something Else?

[mikey360]

I am the proud second owner of a 2007 Fleetwood Providence with a CAT C7 engine. The original owner does not recall if he had ELC coolant installed. The coolant is red in color. I'm lead to believe ELC is red and the 'regular' coolant is something else.

Fleetwood says they would have shipped this unit with 'regular' coolant.

Is there any way to tell what is in the motor; ELC or regular coolant?

Thanks for the wisdom.

[wolfe10]

You are wise to ask, as mixing coolant chemistry is not a good idea in any engine.

Sadly, color is not a good indicator. It is within a particular coolant manufacturer, but not across the industry.

If the OE can recall where he had it changed, call them and have them pull the ticket. Since most pay for things like that on a credit card, if he is really interested in helping, I suspect he can find out.

If not, with the low price of coolant compared with engine or radiator, it may be wise to drain and replace with a coolant you will know-- and yes many of us with Caterpillar engines have switched to ELC (me included).

Also, suggest you join the Caterpillar RV Engine Owners Club, an FMCA Chapter. Their next rally is in Kerrville TX in the spring. Lots of fun and some good technical seminars as well. A good way to learn the "care and feeding" of your engine and whole coach.

http://catrvclub.org/

[rossboyer]

If you decide to change to ELC yourself, it is very difficult to drain all of the old coolant. This coolant needs to collected and disposed of as toxic waste. The coolant is also poison to dogs that seem to like it. Flush several times with tap water. I would recommend changing both thermostats during this process. Each time start the engine to heat the water until the thermostats open. It takes about 20 minutes to get the coolant up to temperature to open the thermostats. Drain between each time. After the fluid is clear when draining, you may want to use a coolant system cleaner. There is a CAT recommended product. Once that is flushed out with at least two fills of tap water and running the engine, drain and fill with distilled water and run engine again. Drain and repeat filling with distilled water and run engine again and drain. You will not be able get low enough protection if you you use 50/50 diluted ELC because of some distilled water still in the system. Add ELC concentrate not the 50/50 mix. Use enough ELC for half the capacity that FLeetwood states for the coolant capacity for your coach. You may have to call your chassis manufacturer to get the capacity of your cooling system. My coaches capacity is 19 gallons; therefore I used 9-1/2 gallons of ELC. Finish by filling with distilled water. Your system should now be protected to about 50 degrees Fahrenheit below zero. To the remaining 1/2 gallon add distilled water to fill the container. Use this 50/50 mix to add coolant when needed. This whole process of draining, flushing till clear, cleaning, flushing till clear, two fills and flushing with distilled water, and final filling with ELC took me all day. It is not difficult to do all this, it just takes time.

[mikey360]

Well, after a careful inspection, I've found a badly faded decal on the radiator shroud that indicates the coolant is NOT ELC. Which means this 3 year coolant has been in the engine for 5 years. And the two thermostats have also been in there since sometime in 2006. I read somewhere those need to be replaced much earlier than 36,000 miles and 5 years. I'm getting the valve lash adjustment done tomorrow. And I'm having them install ELC and two new thermostats. I'm going to have a talk with the service manager about ensuring a good flush. I'm worried about corrosion.