how to property change anti freeze

[maxwell18]

I have a 2000 H/R Ambassador 34ft Cummins 260hp 70K miles and want to know how property .change out the anti freeze. I know it is different then change a car. Also would like to know how to change the generator Onan Diesel . I need to know what products to use and do I need to flush the systems.
Thanks

[H. Miller]

Not enough info.... Depends on what type AF is in the MH AND what type AF you're going to...

[maxwell18]

I don't know what is in it and don't what to put in it. That was part of my reason for question?

[dons2346]

This from Brent Wolfe, a knowledgeable guy when it comes to engine maintenance. Coolant Change Procedure

[Mr_D]

Originally Posted by dons2346

This from Brent Wolfe, a knowledgeable guy when it comes to engine maintenance. Coolant Change Procedure

Ya beat me to it!!

I just changed out my coolant and replaced all water hoses and belts. Thought I would share the experience.

To my knowledge all RV manufacturers use a “low silicate coolant for diesels” with included or added SCA. Coolant needs to be changed per manufacturer’s instructions (usually every 3 years). Additionally the SCA, pH and freeze point need to be checked on regular intervals using SCA test strips and SCA added as needed. The test strips are inexpensive and easy to use. When either the time lapses (time starts when coolant is installed in cooling system, NOT when purchased) or testing reveals an out-of-line conditions like pH or freeze point, it is time to change it. You can avoid all the testing and SCA adding, and go to 6 year change intervals by going to an Extended Life Coolant and get better cooling system protection as well. Whichever coolant you choose, most of the steps are the same. The job is reasonably time consuming TO DO RIGHT, but low-tech.

First step is to determine your total cooling system capacity. Your chassis maker or coach maker, not your engine manufacturer is the proper source. Then buy enough coolant (concentrate, not pre-dilute) to make up 50% of that volume. If going back with a coolant that requires additional SCA, purchase that as well. Also purchase 1.5 times system capacity of distilled water for a final flush plus final fill (50%).

Turn dash heater to full hot for the rest of the procedure—fan off. With the engine cold or at least cool, drain coolant. On some, there is a drain ****. On others, pull the lower radiator hose. Two Rubbermade 10 gallon storage bin lined with black trash sacks so they don’t get dirty work well. At the end of the whole process, use a coffee can and funnel to pour old coolant into new coolant/water containers for recycling. Our city maintenance shop recycles coolant for free.
Refill cooling system with tap water. IMPORTANT: Be sure to remove any air lock from the thermostat housing. Some systems have a hose set up for this—on ours I just loosen the coolant line to the air pump and bleed the air out. Allow engine to warm up (using the cruise control to select idle speed of 1,000-1,100 speeds this up). Run for about 10 minutes at regular temp. If the temp gauge does not rise as normal, you likely have an air block and need to bleed the thermostat housing. Allow engine to cool 20-30 minutes and drain again. Repeat until the effluent color is clear.

At this point, if this is the first coolant change on a 2-3 year old coach and you are not changing coolant brands/types, skip right to “Last rinse”. For older systems or when switching types of coolant, add a Cooling System Cleaner. Follow the directions. Run, allow engine to cool, drain and again flush until effluent is clear. The flushing is markedly sped up by pulling off the heater hose (usually 5/8” to ¾” lines) going to dash heater/motor-aid water heater, etc from the water pump. Put a hose nozzle in the hose and let it run until it comes out clear. Run the engine to temperature at least once with tap water.
If your hoses are over 3-4 years old, this is a good time to change them as well (before last rinse). Same for thermostat(s).
Last Rinse is with distilled water. At $.62/gal at Walmart, it is silly to skip this step and leave your system full of high-mineral content water (there will be several gallons of residual water that you can not easily remove). Run engine for 10 minutes after getting to operating temperature. Cool and drain. Also drain and flush your coolant overflow container and refill with new coolant/distilled water.

Add the proper amount of Coolant CONCENTRATE (NOT PRE-DILUTE) to make 50% of cooling system capacity. So for a cooling system with 20 gallons capacity, add 10 gallons of Coolant CONCENTRATE (plus 1/2 overflow container capacity). Top off with distilled water to achieve your 50/50 mixture—it doesn’t matter if you only have to add 1 gallon or 10 of distilled water, you KNOW you have the proper 50/50 mixture.

This is also a good time to clean the OUTSIDE of the radiator/after-cooler whether you have rear or side radiator. On rear radiator, most if the debris will be on the FRONT of the after-cooler (accessed from under the bed). On side radiators, most debris is on the outside of the after-cooler (side of coach). If it is just dirt, a hose and regular nozzle is all you need. If greasy or oily, use Joy liquid (dish washing detergent) in a spray bottle. Be SURE to rinse it off completely. You need to insure that the perimeter is as clean as the center. Ya, I know it is easier to see the center, but the fan blades "sling" the dirt to the perimeter.

Check belts while you are in there.

Some people contend that using distilled water is too much. I have many gallons of distilled water, long life antifreeze and almost all the radiator hoses I need waiting to start. Just found one more hose I need to buy though, a 2¼" to 2¾" reducer.

[spike45]

Originally Posted by maxwell18

I have a 2000 H/R Ambassador 34ft Cummins 260hp 70K miles and want to know how property .change out the anti freeze. I know it is different then change a car. Also would like to know how to change the generator Onan Diesel . I need to know what products to use and do I need to flush the systems.
Thanks

Bruce,

I am betting that your engine is an ISB 5.9L. This Cummins engine model does not require HD Diesel antifreeze for pitting protection like the larger Cummins models found in motorhomes. You can use any product meeting ASTM D3306 meaning light duty automobile antifreeze is more than sufficient. May I suggest Shellzone as it is easily found at auto parts stores and truck stops. You may also find suitable LD coolants from Zerex as well. Avoid the use of DEXCOOL and coolant stating that they are acceptable substitutes for that coolant.

As for changing the coolant, this may be simpler:

Your coach manufacturer may have the total fill capacity. You really need to have it if you want to end up with a 50/50 or close to that.

Drain the system and measure how much you were able to get. Assuming the system held 12 gallons as an example, you drain 10 gallons, you then must have 2 gallons left that you cannot get out.

Fill the system with water. Leave the radiator cap off. Start the engine. Put water into the radiator or surge tank while the drain cocks are open. The engine may have one near the oil cooler on the exhaust side of the block. The oil cooler is near the front of the engine. Continue running and constant refilling/draining until the drain water becomes water clear or close to it. Some old coolant will not matter.

If you have determined the approximate system capacity, put in half of that capacity as antifreeze concentrate. Fill the rest of the volume with water. You may be able to buy demineralized water at Walmart that is treated by reverse osmosis. This will be fine. Distilled water is fine. Using distilled water to flush is pointless. This is not brain surgery.

Run the engine on a short trip and check the freeze point of the coolant. If it is in the range of -23F to -45F, you are good to go. If you really did your homework and got -34F you are at 50/50.

[gacamp]

If you will search youtube for Onan coolant service you will find a very good detailed video on how change the the coolant in your generator.