A Look at Motorcoach Coolants and your Cooling System, Part 2 by James Sonntag

A Look at Coolant and Your Country Coach Cooling System – Part 2

by James Sonntag, CC owner, a retired engineer from a major oil company

*SHERRY'S Note: Mr. Sonntag wrote this article back in 2004. Recently when I contacted him regarding sharing his article in the Country Coach Friends Inc. Club newsletter, he agreed to my reprint of the original article, with this one request. Some things may have changed over the years, and so it would be good to have someone give the article a good read-through. Country Coach Corp's David Diamond and Doug Beaudry were gracious enough to share their time and attention giving it a review for me. Thanks guys, www.countrycoach.com) Part 1 of Mr. Sonntag's article was posted previously here in.

Maintaining the Coolant in Your Coach – Coolant service procedures and coolant service life are determined by the coolant type now in your coach. Country Coaches built prior to model year 2000 and “early” production during the 2000 model year had their engine cooling systems originally filled with “Heavy Duty, Partially Formulated Coolant to which SCA as added” (Type 2), or with “Heavy Duty, Fully Formulated Coolant” (Type 3) depending on the age of the coach. As the life of these coolant types is only two years, your original coolant should have been flushed and replaced by now.

At the next scheduled replacement, you should change to one of the new Heavy Duty Extended Life Coolants if you have not already done so. Check with your engine manufacturer (see Additional Reading at the end of this article) to determine their extended life coolant recommendation, either Hybrid or OAT.

Coach’s built as “late production” during the 2000 model year and thereafter had their engine cooling system originally filled with Fleetguard ES Compleat PG. This is a “hybrid, extended service interval coolant” which, when properly maintained need not be replaced until testing shows condemning limits are exceeded. This coolant is expected to last four to six years.

For model year 2000, the identification number of your coach will identify the original engine coolant. The following coach numbers are the first to use Fleetguard ES Compleat PG. This can be confirmed by the coolant color, which is “blue.”

Model Name                                 Serial Number

Magna, Affinity, Concept              5845

Intrigue                                         11061

Allure                                            30493

Onan generators, until 2004, have been supplied to Country Coach with either “Heavy Duty Fully Formulated Coolant” or “Heavy Duty Partially Formulated Coolant.” The life of these coolants is two years. At the next scheduled replacement, changing to one of the new Heavy Duty Extended Life Coolant is recommended. The coolant should be of the same brand and type as used in the coach main engine.

During production of model year 2005 coaches, determine which coolant you have by taking a coolant sample from the Onan’s coolant recovery tank (but only when the Onan Engine is cold) and look at the color. If the color is “blue,” you have the new ES Fleetguard Compleat PG coolant.

All heavy-duty diesel engine cooling systems, including those filled with Extended Service Interval coolant, require periodic inspection and maintenance. You, as the coach owner, are the best advocate for proper cooling system maintenance and for detecting early warning signs of cooling system failure.
If you perform your own maintenance, remember that hot cooling systems can be very hazardous when opened. Never remove the radiator cap or otherwise open a cooling system until the system has cooled to ambient temperature. All required coolant tests, discussed below, are to be conducted with the coolant temperature between 50-degrees Fahrenheit and 130-degrees Fahrenheit unless a coolant manufacturer’s directions specifically say otherwise.

The following general recommendations are good practice:

1. Look on the ground beneath the engine and radiator each morning before traveling. Coolant (or other vital fluids) which have leaked on the ground overnight invite your further inspection as to their origin and cause. If you do find a leak, laying a newspaper on the ground may help identify what fluid is leaking, and its origin.
   
2. When checking engine oil, take two seconds to visually scan the engine compartment radiator hoses for unusual bulges or cracks, hose clamps for seepage and leas, and belts for abnormal wear, fraying or cracks.
   
3. Periodically check the radiator and coolers exterior for debris which are blocking airflow, such as as leaves and bugs.
   
4. When the radiator cap is opened to top off the coolant, visually inspect the radiator cap and radiator neck for the presence of engine oil or fuel. A black, oily ring invites further inspection by a qualified diesel mechanic at the earliest possible date.
   
5. When topping off a low coolant level, never mix coolants of different types. Also, stay with the same coolant brand if possible. Know the brand name and the type (i.e. heavy duty fully formulated, extended service hybrid, or extended service OAT) of the coolant currently used in your main engine and our Onan generator. (Attach notes to the radiator filler necks as a reminder).   Consider carrying a few extra gallons of your coolant on board for emergencies and for topping off. (And should you ever need more coolant and the same brand is not available, your container will help you match to other coolant brands of the same coolant type and specification.)

   For coaches using ES Fleetguard Compleat PG, pre-mixed 1-gallon bottles are available as Fleetguard P/N CC2835.

6. Top off only with fully formulated, pre-mixed coolants. These are coolants which do not require the addition of SCA or of water before use.

Use fully formulated products labeled with the words “Premix” or “prediluted” or “coolant.” Products labeled “concentrate” require dilution with equal parts water. High purity, demineralized water is not always available. Premixed products avoice the temptation to use untested tap water.

Again, for coaches using ES Fleetguard Compeat PG, premixed 1-gallon bottles are available as Fleetguard P/N CC2835.

7. Have a coolant sample drawn at least twice per year from the main engine and the Onan generator. Draw the sample from the drain cock at the bottom of the radiator for the main engine and at the coolant drain plug for the Onan generator. (Do not sample from the radiator expansion tank.) Request service personnel to perform the following and to include all test results on the service order.
   
1. Visually inspect the coolant to insure the color is correct, the coolant is clear, and there is no debris or sludge. The coolant sample must not indicate contamination by engine oil, fuel, grease, solder bloom, silica gel, rust or scale. Note that if the coolant is found to be contaminated, the coolant must be drained and, before refilling, the cooling system must be cleansed using a cleaner specific to the contaminant(s).
   
2. Test the coolant sample for glycol concentration (i.e. “freeze point”) and for SCA concentrations (Note: OA coolant does not require SCA testing). Use coolant manufacturer test strips which are specific to your coolant. (Note: if possible, freeze point should be determined by testing with a refractometer. Test strips alone are not precise indicators of freeze point, although they do give an indication.)

For Fleetguard ES Complete PG coolant use Fleetguard Coolant Test Strips, P/N CC2602B. Follow the instructions provided with the test strips. Note that the test strips are dated and that out of date test strips will give erroneous results.

3. Based on test results, replenish the additives by using a conventional SCA or an Extended Service Additive (ESA), in liquid form or as “need-release” coolant filters. Each coolant manufacturer has its own system for determining the amount of SCA/ESA to be added. Typically the amount is based on interval since the last cooling system service (miles or engine hours) and on the capacity of the cooling system. Simply follow the coolant manufacturer’s directions. Recall that if the coolant manufacturer offers you a “conventional SCA” and an ESA for your specific coolant, the ESA is the better choice.

For coaches using Fleetguard ES Compleat PG coolant, replenish additives using the Fleetguard ESA. “ES Extender,” using extended service interval coolant., the chemically free filter is Fleetguard P/S WF2077. Note that filter WF2077, even though chemically free, should not be used with extended service coolant. Its filter element is not designed to be in service 1-year.

Hydro-Hot Heat Systems

  The Hydro-Hot Hydronic Heat System, manufactured by Vehicle Systems, Inc, does not use engine coolant. It uses a PG-based “heat transfer fluid” which has been approved by the FDA as “Generally Recognized As Sale” or “GRA”. Never use Antifreeze/Coolant designed for Automotive/Diesel applications and never use RV/Marine Antifreeze as heat transfer fluid in the Hydro-Hot System.

  Suitable products with the required FDA Approval are available under the names of Virginia Pipe Saver, AMSOIL Propylene Glycol Antifreeze and Engine Coolant, Enviroguard, NoBurst, Safe-T-Therm, and CAMCO Boiler Antifreeze for Hydronic Heating and Cooling Systems.   If you can not find one of these products locally, you can order the transfer fluid through a trusted service center or order it from the Hydro-Hot manufacturer Vehicle Systems Inc at 800-685-4298. They offer the product in 1-gallon containers as Part No. MSX-300-270.

Additional Reading Heavy-duty diesel engine manufacturers have detailed their specific engine coolant and coolant service requirements. For those who wish to read more on this subject, the following information is recommended.

Cummins: Purchase the most recent copy of Service Bulletin No. 3666132, “Cummins Coolant Requirements and Maintenance” by calling the Cummins Customer Assistance Center at 800-343-7357. ( A copy of this document was not available at the Cummins website at press time.)

Caterpillar: Obtain a copy of Caterpillar Service Bulletin SEBU6385-05, “Operation and Maintenance Manual, Caterpillar On-Highway Diesel Truck Engine Fluids Recommendations,” from a Caterpillar dealer. This document is available on the interet as www.cat.com. Find it by putting your browser on “Services” then clicking “Parts and Services” from the drop down menu. On the next page, click on “Service Publications” (in the list on the left-side of the page). Then click on “Caterpillar On-Highway Diesel Truck Engine.”

Detroit Diesel: Obtain a copy of Publication 7SE298, “Coolant Selections.” This document is available on the internet as www.detroitdiesel.com. Find it by putting your browser on “Support,” then put your browser on “On Highway” from the drop down menu. This will cause a fly-out to appear on the right, reading, “Technician’s Guides.” Click on “Technician’s Guides” On the Technicians Guide page, click on the Guide “Coolant Selections.”

Fleetguard has good information on their website www.fleetguard.com, and may be contacted at 800-22-FILTERS.                                                   -END@