SCA Testing

[wolfe10]

Just a reminder: If you have "low silicate coolant for diesels with SCA's" (we can call this "regular" coolant for your engine) as opposed to a long-life coolant like Caterpillar ELC, YOU MUST TEST AND REPLENISH THE SCA AS IT IS USED UP. This is the coolant that came from the chassis/coach maker in all but a handful of cases.

Failure to keep SCA's at proper level hampers cooling and on larger engines with replaceable cylinder liners, can lead to cylinder wall erosion.

Test strips are available in small quantities: Fleetguard CC2604-A 4 pack. NAPA FIL4105. NAPA and other parts houses that cater to the OTR truck trade stock them. Go into a suburban NAPA and they might stare you like a deer caught in the headlights or ask you to buy a whole box of the individually wrapped strips.

They are date sensitive, so MAKE SURE THEY HAVE NOT EXPIRED. Expired strips can give false results. They are easy to use-- just follow the directions-- dip in coolant, wait, read.

Do NOT just use a set amount of SCA additive (it comes as a liquid and for coaches fit with a coolant filter, in different quantities in filters).

Overdosing is almost as bad as under-dosing.

If you do have a coolant filter, they come with different number of "units" of SCA. When adding SCA's it is always safer to slightly UNDER dose the system and re-check it with the test strips after a few hundred miles and re-dose if necessary.

The test strips also test for freeze point and pH. If either is way out, it is time to drain, flush and change coolant.

And even if everything tests OK, coolant still needs to be changed every three/four years (per coolant manufacturer's recommendations). Said another

way, the strips do NOT test for all the anti-corrosion additives that are important to your engine.

If, as many of us have done, you switch to a long life coolant such as Caterpillar ELC at your next coolant change, there is no SCA testing. After 3 years a "booster" is added. The ELC is then good for another 3 years.

Your cooling system is important. If the simple testing and additive steps required of ALL diesels (Caterpillar, Cummins, Detroit Diesel, etc) are

followed, the "inside" of your cooling system will give you many years of trouble-free service.

And while you are there, particularly if a rear radiator, access the engine from the top and shine a strong flashlight inside the fan shroud/between the fan blades. Make sure the perimeter of the after-cooler (that is what you are looking at) is as clean as the center. The blades "sling" the dirt to the perimeter.

Brett Wolfe

[bigdgr]

Brett: We purchased a 2005 Travel Supreme Envoy from a dealer who changed all the fluids. I saw him top up the anti-freeze with regular Prestone. The coach has 100,000 miles with a cat 350 engine and runs like a new one. We have put around 2500 miles on it. Do I need to change the coolant ? Do I need to go to a Cat dealer for the correct coolant ? Thanks in advance, Darrell

[FMCANationalOffice]

Darrell,

Welcome to the FMCA Forum.

In a word, YES, you need to change the coolant if someone put in regular Prestone like you would buy at Walmart for your automobile. That is a high silicate cooant with no SCA and is NOT approved for your engine (or most other diesel engines for that matter.

Pull out your Caterpillar "Operation and Maintenance Manual" that came with the coach (or pick up one from any Caterpillar dealer). It has a section on the cooling system and includes the mil specs of approved coolants.

Prestone does make a "low silicate for diesels coolant with SCA", but it sure isn't the regular stuff you can get at most Walmarts.

Many manufacturers make coolants that meet these specs.

You might also want to consider switching to Caterpillar ELC. No SCA adding/testing is needed and it is good for 6 years vs 3 for regular low silicate coolants.

Brett

[Spike45]

Darrell,

Welcome to the FMCA Forum.

In a word, YES, you need to change the coolant if someone put in regular Prestone like you would buy at Walmart for your automobile. That is a high silicate cooant with no SCA and is NOT approved for your engine (or most other diesel engines for that matter.

Pull out your Caterpillar "Operation and Maintenance Manual" that came with the coach (or pick up one from any Caterpillar dealer). It has a section on the cooling system and includes the mil specs of approved coolants.

Prestone does make a "low silicate for diesels coolant with SCA", but it sure isn't the regular stuff you can get at most Walmarts.

Many manufacturers make coolants that meet these specs.

You might also want to consider switching to Caterpillar ELC. No SCA adding/testing is needed and it is good for 6 years vs 3 for regular low silicate coolants.

Brett

More accurately, if the amount of coolant refill (top off) is just a few quarts that you know of, then the CAT ELC chemistry is not compromised. While CAT says there is no need to test the coolant it does contain nitrite and molybdate, two coolant SCA additives that can be easily tested for. These two additives do deplete in this coolant and are replaced when you add a bottle of Caterpilar ELC extender liquid. You could certainly do that but do not go to the extremes of changing coolant for a small amount of mixing with another coolant.

[bigdgr]

For Brett and Gary: I called the local Cat dealer today and he said the regular anti freeze was ok just add 1 quart of SCA to the radiator. I asked about the ELC and he said that would be better but would cost 2 hours labor plus the coolant. It works out to $ 7.00 vs $ 300.00+. I am not against spending the $ 300 but wonder if adding the SCA to the regular anti-freeze now and changing to ELC later (next spring ) would cause any problems. Thanks to you both for the help. This is my first diesel pusher and I love it!! I do want it to last so I will wait to hear what you both think. Darrell

[FMCANationalOffice]

For Brett and Gary: I called the local Cat dealer today and he said the regular anti freeze was ok just add 1 quart of SCA to the radiator. I asked about the ELC and he said that would be better but would cost 2 hours labor plus the coolant. It works out to $ 7.00 vs $ 300.00+. I am not against spending the $ 300 but wonder if adding the SCA to the regular anti-freeze now and changing to ELC later (next spring ) would cause any problems. Thanks to you both for the help. This is my first diesel pusher and I love it!! I do want it to last so I will wait to hear what you both think. Darrell

Again, you need to find out what "regular antifreeze" was used.

Regular automotive antifreeze (high silicate) is NOT OK.

Low silicate coolant for diesels is OK and if it tests low on SCA, SCA can easily be added. Retest and add more if needed. The test strips are only about $1 each.

Find out the coolant part number they used. Post it here for us to research or look it up yourself. Again, your Caterpillar owners manual will give the MilSpecs that coolants must meet for your engine.

Brett

[Spike45]

For Brett and Gary: I called the local Cat dealer today and he said the regular anti freeze was ok just add 1 quart of SCA to the radiator. I asked about the ELC and he said that would be better but would cost 2 hours labor plus the coolant. It works out to $ 7.00 vs $ 300.00+. I am not against spending the $ 300 but wonder if adding the SCA to the regular anti-freeze now and changing to ELC later (next spring ) would cause any problems. Thanks to you both for the help. This is my first diesel pusher and I love it!! I do want it to last so I will wait to hear what you both think. Darrell

Per Caterpillar Fluids Recommendations Guide in the Coolant Section, Caterpillar prefers their ELC product for their engines. They do list as acceptable for use any coolant that meets ASTM D6210. Coolants that meet the ASTM designation must have an SCA, supplemental coolant additive, precharge in the coolant. If the MH dealer put in Prestone coolant but of unknown type, you can test your coolant using coolant test strips available from Baldwin, Donaldson, Fleetguard. Due to some issues with the foil wrapping process used for Fleetguard CC2602A or CC2602B test strips, I would avoid buying those unless they have an expiry date of AFTER August 2011. Before that we had some issues that lead to unreliable readings. You can get your coolant tested at a Cummins distributor. They can test with their bottled CC2602 test strips. I do not recommend purchasing a bottle of any of these test strips as the cost does not justify the two or so test strips you will use in two years before they expire. Some Kenworth dealers will do the same test as Cummins but at a lesser cost, MAYBE. If the coolant in your MH is not CAT ELC, strawberry red color, but is some other color it will still need to have an SCA precharge of at least 2.0 units per gallon as measured on the test kits from Baldwin, Donaldson, Fleetguard.

With sufficient precharge using liquid SCA products like Baldwin BTA, Donaldson equivalent to DCA4, or Fleetguard DCA4, Pencool 2000 or 3000, even Caterpillar Cooling System conditioner ( I think they use a different name now for that). There are plenty of liquid SCA products you can use to precharge or put a new precharge in if your coolant SCA level is below 1.2 units per gallon or as measured on a Penray test strip, less than 1200 PPM nitrite. Generally, one pint of any of these liquid SCA products will treat 3 gallons of coolant capacity. Plus, if your CAT engine does not have a coolant filter, add an additional pint for up to 12 gallons capacity as a SERVICE dose. SCA additives like the similar additives found in Cat ELC are sacrificial chemicals and will deplete.

Caterpillar does not require the use of ELC in their engines. They prefer it. They do REQUIRE that any coolant used meets ASTM D6210 which their ELC does meet. Are you sufficiently confused now?

[FMCANationalOffice]

Are you sufficiently confused now?

Well explained.

Best: Caterpillar ELC (BTW that is what I use in my Caterpillar powered motorhome).

Acceptable: A low silicate for diesel coolant meeting the ASTM D6210 specs. This coolant requires monitoring and adding SCA.

UNaccpetable: High silicate coolant for automobiles-- like the normal Prestone you get at Walmart. And the possibility that they used this one is the reason I recommended verifying by part number what they used!

BTW, I think you will find that Cummins and Detroit Diesel have very similar requirements.

Here is a link to Prestone's website-- as you can see, they make a wide range of coolants, many for automobiles and light trucks (not intended for diesels) as well as the correct coolant for you diesel. If you click on a coolant and then on "Instructions" you will get a better feel for what is required. This is AFTER you find out exactly what Prestone product the dealer used.

http://www.prestone.com/products/antifreeze_coolant/product_list

Brett

[bigdgr]

Thanks guys. I think I'll get the Cat dealer to change to ELC after draining and flushing the system. It seems to me that it will be money well spent. Thanks again to all. Darrell

[hermanmullins]

Brett and Gary,

Thanks for some great information on cooling systems.

I have never changed or even thought of changing my fluid.

I have copied this complete post and will study it all and see if I need to make any changes.

2002 Dynasty Cummins 400 ISL.

[wolfe10]

Herman,

You are WAY past due for a coolant change, particularly on your linered engine.

The questions you need to address are:

1. Do you want to do the work yourself or hire it out. There is nothing complex about doing it and most owners will do a much better job because doing it right is time consuming.

2. What coolant do you want to use. I and most others have switched to the OAT-based longlife coolants. Caterpillar has their ELC (Extended Life Coolant). Cummins/Fleetguard also has one. If you do switch from a regular diesel coolant to a longlife coolant, you will need to use a cooling system cleaner. Again, this is well documented by both Caterpillar and Cummins.

If you plan to do it yourself, I will be happy to post the step by step instructions. One of the questions will be "where do I recycle the old coolant". A call to your city's vehicle maintenance department will answer that question. Ours happily accepts used coolant at no charge.

Brett

[hermanmullins]

Herman,

You are WAY past due for a coolant change, particularly on your linered engine.

The questions you need to address are:

1. Do you want to do the work yourself or hire it out. There is nothing complex about doing it and most owners will do a much better job because doing it right is time consuming.

2. What coolant do you want to use. I and most others have switched to the OAT-based longlife coolants. Caterpillar has their ELC (Extended Life Coolant). Cummins/Fleetguard also has one. If you do switch from a regular diesel coolant to a longlife coolant, you will need to use a cooling system cleaner. Again, this is well documented by both Caterpillar and Cummins.

If you plan to do it yourself, I will be happy to post the step by step instructions. One of the questions will be "where do I recycle the old coolant". A call to your city's vehicle maintenance department will answer that question. Ours happily accepts used coolant at no charge.

Brett

Will do. I will probability do it myself when I get my arm out of this sling. (Shoulder repair). When I get there I will post you for instructions. My son works for our local City government and he can get it disposed of. In the mean time I will research volume of my system and cost of the several coolant on the market. Again thanks for your help.

[jamestouchstone]

Hi Burt, I have a 2003 American Revolution and do all of the maintenance myself.

I have added SCA when test strips indicated. Engine is 350 Cummins ISC.

What is the correct way to change the coolant? I only have used oem Feetguard products?

Do I need to flush the system and if so what to use?

What is the fill procedure?.

I will check this post for your follow up.

Thanks for your input.

jimt

[wolfe10]

From an article I wrote:

Cooling System 101

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.

[DocWobblin]

Brett, I have a 98 Coachmen w/ the 5.9 Cummins 275 hp. I bought the unit used with 51000 miles last year....unit is on a Freightliner chassis. Does this diesel require the SCA additives?...Thanks, George Martin

[wolfe10]

Doc,

Best advice is to see what mil specs your Cummins owners manual recommends for your engine.

If you don't have a Cummins manual, get one from any Cummins dealer (will need your engine serial number) .

You could also give Cummins a call with your engine serial number and ask them: Cummins 800 343-7357

Brett

[tzimmermn]

Great infomation Brett Wolfe. I am fixing to change the anti-freeze in our 2007 Winnebago Tour with the 400 HP Cummins ISL CM850. This is first change and unit came filled with the Alliance Brand fully formulated coolant with SCA's. We purhased this unit in Sept of 2009 and book indicated a 5 year replacement. After the last trip, I have noticed a very small amount of white residue settled in the overflow tank. We bought the RV with about 11,000mi on it and now have 25,000 mi on it. I agree with your assessment, that it is probably wise to replace at the 3 to 4 year interval. I am a DIY, but I think I goofed up a little bit on the coolant. Because it was a Cummins, I assumed that it was filled with fleetguard antifreeze and got there strips and DCA-4 which they stated would work as a DAC-2. Although I could read the SCA's, the freeze protection was hard to read, but was thought to be OK. After putting the DCA-4 in the radiator, I relized later that I may have been using wrong SCA and/or test strips. I went and got the Penray test strips and checked the coolant. It has read to be adequate on nitrates. Strips were much easier to read. I am not sure of the compatablility of the DCA-4 with the Alliance Brand anti-freeze and question the readings on the test strips, especially if I used an incompatible SCA. It all may be mute, as I plan on changing immediately.

I have crawled around underneath looking for a low point drain, but have found none, All I see is the 2 block valves that are used to block the heater and the one drain valve on the return heater line to flush the line out from the heater. We have a rear radiator. I could not see or identify a drain valve for the radiator and it would appear the only way to flush the system is to dump the radiator hoses. I also see a drain c***k on the driver's side on the bottom of a casting that appears to be bolted onto the side of the engine block just below the turbocharger. I suspect this may be a coolant drain for the casting but not a low point drain for the engine block. Regarding flushing, I have both softened (using salt) water or hard water available and have purchased distilled water to use for the final flush which I may need to get more to flush more than once to purge the system.

Given the above history, would you recommend using the the fleetguard restore or just flush the system with water? Would you use only the distilled water to flush system, or the hard water or soft water that I have available at my outside faucet? Regarding refilling, the Cummins fill instruction on the back of the coach, do not talk to opening any high point bleed to expell air and only talk to filling through overflow tank at a rate not to exceed 3.5 gpm. It then talks to opening the inlet valve on the heater hose and to open the drain valve on the return heater hose to force coolant through the heater lines and finally to the drain on the return heater line. Not sure if this is how Cummins vents the air from the system, or if I need to access from the top and try to vent air from an appropriate high point coolant line. I am a little new at this and as you can probably tell from the mistakes made above.

[wolfe10]

Terry,

Pull the radiator lower hose to drain. Look at what comes out and THEN decide whether you need a cooling system flush. If so, follow the directions.

Then flush with tap water until that is clean/clear.

Then use distilled water for the final flush.

Fill with 50% of cooling system capacity with coolant CONCENTRATE and then top off with distilled water. This easily accounts for the several gallons of water trapped in the lines from engine to dash heater as well as heater core.

Many of us have switched to the new OAT-based coolants-- basically 6 years with no SCA's to test. Cheaper in the long run. Caterpillar has one. So does Cummins. I would use the one sold by your engine manufacturer.

Consult your chassis maker (who designed and installed your cooling system for the correct way to bleed the air from the cooling system.

Brett

[cmarq]

Reply to Docwobblin, The Cummins 5.9 is a" parent bore engine" it is not an engine with liners which will pit without SCA. You do not have to use it

[tzimmermn]

Thanks Brett for the info. I will pull lower hose to drain and see what I get. I liked the idea of using the rubbermaid storage containers. I was wondering what I might use as I know how messy things can get with anti-freeze. It was a very good suggestion and I plan on going up and getting a couple tomorrow and planning for the change this weekend. I like the idea of the low maintenance OAT. I will go down Friday and see what the Cummins folks say about what I need to do for the high point vent or if the block will self vent when you fill it up.

Thanks for all your assistance.

Terry Zimmerman

[wildebill308]

Terry,

Please let us know what your Cummins dealer tells you.

Bill

[wildebill308]

Not trying to hijack the thread but I am wondering if the expansion tank on my 5.9 Cummins was installed by the engine/chassis maker, Freightliner, or by Fleetwood.

Mine is looking kind of rough with the mold line in the center deteriorating and getting crumbly.

Bill

[wolfe10]

Bill,

Check with Freightliner. And, this is a common problem. The plastics in the expansion tanks were designed to be used under the hood of a truck. With the grills on the back of a DP, the tanks are exposed to UV light, which breaks them down.

When in storage outdoors, put a sheet of cardboard inside the back grill to reduce deterioration due to UV light.

[wildebill308]

Good tip! I wish the previous owner had heard of that.

Bill

[hermanmullins]

Brett.

Bring me up to date on the coolant. Is the Extended Life Coolest (ELC) good for three or more years? How often should I have it tested? I just had the system drained and flushed and the ELC put in. Plus I had every dang filter they could change, changed except the air. I'm not even close to moving from Yellow to Red. Now watch the next time I check the fluids it will be solid Red.

Herman