How to calculate the amount of SCA/DCA needed.

[DieselPower]

There was a comment made in another thread about how much of a PITA it is to figure out how much DCA/SCA you need to add to your coolant when using test strips. Personally I never really gave it any thought since I have a handy little slide chart that was given to me years ago when I worked for a International truck dealership. I guess it's one of those things you never realize how handy something is until you think about it.

In any case, I have scanned and uploaded pictures of the chart. The first two pictures are of the outside of the slide chart. The third and fourth pictures are of the internal slide card. The fifth picture is of what it will look like assembled. Please pardon the greasy finger prints, it's seen a lot of use over the years.

Probably the easiest thing to do is print out the first four pictures. Just right click over the picture and then select print. Trim the pictures out. Cut out the viewing windows in the first and second pictures and a slot at the top to grab the internal card by. Tape the first and second pictures together along the left and right sides. Tape the third and fourth pictures together back to back (be sure it is cut small enough to slide into the previously assembled outside). Now just slide the number chart in the outer body. Using a DCA/SCA test strip take the reading you get with it and slide the internal card out until that number is showing. Find the approximate capacity of your cooling system and the number below it is the amount of DCA/SCA you need to bring it up to about 3.0.


Moderators - Feel free to make a sticky out of this to make it easier for people to find.


http://www.tractorbynet.com/photos/data/500/DCA1.JPG

http://www.tractorbynet.com/photos/data/500/DCA2.JPG

http://www.tractorbynet.com/photos/data/500/DCA3.JPG

http://www.tractorbynet.com/photos/data/500/DCA4.JPG

http://www.tractorbynet.com/photos/data/500/DCA5.JPG

 

[fieldserviceengineer]

The best practice for maintaining the DCA level in diesel engine coolant is to use the manufacturer's recommendation on either how much liquid to add or the correct service filter that is used at each PM interval.

Using your chart method can lead to some who will want to keep the DCA level at the minimum level. False economy as this usually results in having levels in the range of less than 1.2 units per gallon (Fleetguard method) or 1200 PPM nitrite (Penray, Detroit Diesel method) and eventually, cylinder wall cavitation pitting failure.

For sake of good practice and simplicity, the service dose of DCA (Fleetguard DCA4 or DCA2) is one unit per 3 gallons of system capacity. On a 12 gallon system, that is 4 units. Fleetguard DCA4 Liquid is 5 units per pint bottle. Use of Pencool 2000 or 3000 has the equivalent treatment of 4 units per pint. Use either or even mixing the two supplemental coolant additive bases will work. If you use the Fleetguard CC2602 test strips (available in single pack and packs of 4 strips), continue to add the liquid at each PM interval for your tractor or machine. When testing indicates you have exceeded 3.0 units per gallon, do not add liquid or change the coolant filter (if your engine uses chemical charged filters). When the DCA level drops below 3.0 units per gallon, resume the service dose or filter change.

 

[RickB]

I'm not an engineer; just a lowly mechanic. I find the notion of dosing DCA supplements based on the calendar or hour meter while ignoring coolant test results to be absurd. I really can't describe it any other way.

 

[Sully2]

If one knows the total amount of their coolant SYSTEM..all one needs to do is use the test strip...record the results and then call FleetGuard on the telephone. You can tell them what the test strip indicated and they will tell YOU how much of what you need...and charge you for it and drop it in the mail to you. Dont know what can be easier than that???

 

[fieldserviceengineer]

If one knows the total amount of their coolant SYSTEM..all one needs to do is use the test strip...record the results and then call FleetGuard on the telephone. You can tell them what the test strip indicated and they will tell YOU how much of what you need...and charge you for it and drop it in the mail to you. Dont know what can be easier than that???

Trust me on this one, calling Fleetguard to find out how much to add based on the test strip reading will NOT get you an answer. Their technical assistance people do not work off charts such as you describe nor do they any other charts. They will state that DCA (or SCA) needs to be added on a maintenance basis of hours of operation such as what Cummins or Caterpillar would state for their engines.

For the comment made earlier that it is absurd to use engine hours as a basis for doing coolant service, why do you think engine hours based oil change intervals are okay and not so for coolant? Many engines have 250 engine hours as the basis for changing oil and filter. Is that 250 hours at low speed and low to moderate load levels or is that 250 hours at all maximum engine load? Engine companies do not differentiate on standard service intervals. The same for coolant service. if you have leakage and refill low coolant levels with coolant approved by your tractor manufacturer and never refill with plain water or water/antifreeze mixes, the service filter or liquid dose is sufficient to replenish what your engine consumed by running. On the other hand if you are topping off low coolant levels with whatever you pour in, the likelihood of damage from cavitation pitting is much greater. Testing does tell you if your maintenance program is correct for the hours you are running.

What is your goal in coolant precharge? Do you want to keep it at the bare minimum level of 1.2 units per gallon? Or do you keep it at 3.0 units per gallon and the upper end of precharge? Keeping it at bare minimum means you dip into the "precharge" range meaning the DCA protection is so low that cavitation pitting can set in. Keeping to the higher end keeps you away from that danger zone.

If you like to test and make your determination that way, good. That is more money for Fleetguard and other companies. Should you have issues with a cavitation pitting failure, all engine companies will refer you to their published cooling system service interval information. None of them will tell you to test to decide if or how much DCA to add. You are on your own. Good Luck from a Fleetguard Service Engineer, Gary Spires 8^)

 

[fieldserviceengineer]

I'm not an engineer; just a lowly mechanic. I find the notion of dosing DCA supplements based on the calendar or hour meter while ignoring coolant test results to be absurd. I really can't describe it any other way.

Rick,

Nothing lowly about being a service professional. Without you, things will come to a halt. Which of the equipment engines that you repair and service recommends testing coolants for DCA or SCA levels instead of following their maintenance chart on liquid dose or coolant filter change? If you are repairing equipment that does not have such maintenance instrucitons as when to add the dose or change the filter, perhaps that engine does not need the chemical addition. Cummins B5.9L and ISB 5.9L engines are examples of diesel engines that do not have coolant maintenance recommendations that require use of DCA as those engines do not have cavitation pitting failures.

 

[RickB]

Rick,

Nothing lowly about being a service professional. Without you, things will come to a halt. Which of the equipment engines that you repair and service recommends testing coolants for DCA or SCA levels instead of following their maintenance chart on liquid dose or coolant filter change? If you are repairing equipment that does not have such maintenance instrucitons as when to add the dose or change the filter, perhaps that engine does not need the chemical addition. Cummins B5.9L and ISB 5.9L engines are examples of diesel engines that do not have coolant maintenance recommendations that require use of DCA as those engines do not have cavitation pitting failures.

I use Fleetguard test strips and the accompanying chart to determine need and dosage. I'm not sure why Fleetguard's technical staff would not support their own product if I called, but I haven't, so I have no knowledge of whether they endorse and support their own products.

 

[Sully2]

Trust me on this one, calling Fleetguard to find out how much to add based on the test strip reading will NOT get you an answer. Their technical assistance people do not work off charts such as you describe nor do they any other charts. They will state that DCA (or SCA) needs to be added on a maintenance basis of hours of operation such as what Cummins or Caterpillar would state for their engines.

I disagree 1000%. I did exactly as they directed me to do and they sent me the pint bottle and told me how much to add.

 

[DieselPower]

I'm kind of suprised you say to add DCA based on time and not based on what the system actually needs to bring it back up to 3.0. I have seen systems first hand that were treated on a time basis and that had DCA levels that were to high and on the same note have seen ones that were way, way low. It also seems kind of strange since the card I posted here was issued by International and came with a letter from Fleetguard telling the mechanics how to use it properly. I'll have to look around and see if I still have the letter from Fleetguard.

 

[Sully2]

I'm kind of suprised you say to add DCA based on time and not based on what the system actually needs to bring it back up to 3.0. I have seen systems first hand that were treated on a time basis and that had DCA levels that were to high and on the same note have seen ones that were way, way low. It also seems kind of strange since the card I posted here was issued by International and came with a letter from Fleetguard telling the mechanics how to use it properly. I'll have to look around and see if I still have the letter from Fleetguard.

DieselPower: If I read your first post correctly...then you and I are saying the same things....with the exception that you HAVE the "chart" and the lady I talked with at FleetGuard had to look at her's and then tell me what I needed. I distinctly remember asking her a question ( I forget what exactly the question was...but do remember it petained to useing their "extender" in my coolant) and her telling me to hold on a second because she had to look at a different "chart".

I was told by them to use the "time thing" as a basis for CHECKING my coolant...not as to actually ADDING anything. When checked on the time basis using their test strips...then I can tell what I have at that point and then decide to add DCA or not....depending on the actual reading.