Coolant type/make and capacity

[wvirnwkr]

1996 newmar dutch star with 250hp cummings . Coach model dp 3757 need to refill antifreeze with proper type and need to know capacity. Thanks for any help wvirnwkr use 50/50 pre mix or straight antifreeze self mix with distilled water ---capacity?

[Mr_D]

Engine is probably a wet sleeve Cummins. You need a coolant with SCA's to protect the liners from cavitation. You need a heavy duty truck coolant, not car coolant.
This is a liner that shows cavitation damage.

[wvirnwkr]

Thank you mr d. Is there a brand/type that is easy to find and proper way to install. Thanks wvirnwkr

[wolfe10]

Most manufacturers during that time (1996) used a “low silicate coolant for diesels” with included or added SCA. No idea what is in there now or what age it is.


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%). Also a good idea to change the engine thermostat and thermostat gasket as these are a wearing component and it involves very little more work while you are there. I know Caterpillar recommends thermostat (they call them regulators) every 3 years.


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 cock. 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 there.

[Alpine36]

What Brett's said^^^
I'd recommend Fleetguard Compleat EG (blue) for your 96 vintage engine.
It is available from Cummins direct in 100% concentrate for about $24 a gallon. Guessing you'll need about 6 gallons for a 12 gallon capacity system.

[Winemaker2]

Originally Posted by wvirnwkr

Thank you mr d. Is there a brand/type that is easy to find and proper way to install. Thanks wvirnwkr

Be sure to check with chassis mfg not Cummins.
Freightliner cautioned against using any extended life coolant as they were not compatible with their sensors.

[Alpine36]

Exactly why the Fleetguard Ethylene Glycol Compleat formula checks all the boxes, with extreme freeze, corrosion and liner pitting protection good for a very long time. Not to berate the OATs, but for older applications the Compleat is probably a safe bet.

[tom chelbana]

Brett has done a excellent job with what diesel engine owners with wet sleeve engines need to do with their cooling systems. Mr. D photo is what is the end result of not doing the proper job when doing or neglecting to do coolant service. We just had a Ventana owner have this wet liner cavitation problem costing over 17K worth of damage and a number of months without the use of there coach in our NKK group.
Newmar Man

[silvrghst]

Hi
How many gallons did you put in your 1996 Newmar DUTCH STAR 3757,
I have so far put a new radiator in mine and a taller toilet and also replaced all tires.
Will see what elec comes up LOL

[Skip426]

Originally Posted by silvrghst

Hi
How many gallons did you put in your 1996 Newmar DUTCH STAR 3757,
I have so far put a new radiator in mine and a taller toilet and also replaced all tires.
Will see what elec comes up LOL

Hi silvrghst ; the problem with asking a question on an old thread , is you don't know if any of the members who posted to it are still around.
The member who started this thread , hasn't been on the site for over two years .

My chassis is a little longer and Caterpillar engine and side radiator , when I replaced the heater hoses the system took 8 gallons to fill .