Series 50 – Section 5.4 Coolant

Section 5.4
Coolant

The coolant provides a medium for heat transfer and controls the internal temperature of the engine during operation. In an engine having proper coolant flow, some of the heat of combustion is conveyed through the cylinder walls and the cylinder head into the coolant. Without adequate coolant, normal heat transfer cannot take place within the engine, and engine temperature rapidly rises. Therefore, coolant must be carefully selected and properly maintained.‪

The following terms are used throughout this Section and must be understood.‪

• Coolant - The fluid mixture circulating in the engine cooling system.
• IEG - Full strength (non-diluted) Inhibited Ethylene Glycol meeting applicable heavy-duty formulation specifications.
• IPG -Full strength (non-diluted) Inhibited Propylene Glycol meeting applicable heavy-duty formulation specifications.
• SCA - Supplemental Coolant Additives. Used to prevent corrosion, cavitation, and the formation of deposits.
• Initial fill - Any time the cooling system is empty, then filled with new coolant.
• Precharged IEG - Also referred to as a - fully formulated IEG. Contains the proper amount of SCA. Additional SCA must not be used with a precharged IEG at initial fill.
• Precharged IPG - Also referred to as a - fully formulated IPG. Contains the proper amount of SCA. Additional SCA must not be used with a precharged IPG at initial fill.
• Dropout - Sludge or deposit formation in or on cooling system components.

Using a coolant with the appropriate concentrations of SCA is one of the most important aspects of quality engine maintenance. To achieve the chemical balance needed to protect a cooling system, certain coolant basics must be understood.‪

This section provides the directions and information required to ensure cooling system protection for Detroit Diesel Series 50 engines. These recommendations are general rules and reflect the current technology. Specific concerns not covered should be addressed to your local Detroit Diesel representative.‪

The coolant used in Detroit Diesel Series 50 engines must meet the following basic requirements:‪

• Provide an adequate heat transfer medium.
• Protect against cavitation damage.
• Provide a corrosion/erosion-resistant environment.
• Prevent formation of scale or sludge deposits.
• Be compatible with cooling system hose and seal materials.
• Provide adequate freeze protection.

A properly maintained coolant can be used for two years, 200,000 miles, or 4000 hours, whichever comes first. At this time the cooling system must be drained, thoroughly cleaned and filled with new coolant.‪

To achieve these requirements, coolants are mixtures of good quality water, SCA and often an IEG or IPG for freeze protection. The rest of this bulletin will describe the requirements and usage of the water, SCA, IEG, and IPG.‪

Section 5.4.1
Water

Water is the best practical medium for heat transfer. However, water alone can cause corrosion and inherently contains minerals that can produce scale deposits on internal cooling system surfaces. Chlorides, sulfates, magnesium, and calcium dissolved in the water can cause scale deposits, sludge deposits and/or corrosion.‪

Distilled or deionized water is preferred to minimize the adverse effects of minerals in water. The maximum allowable limits for minerals in water are listed in Table "Maximum Allowable Limits for Minerals in Water" . The procedure for evaluating the quality of water is shown in the next illustration. see Figure "Water Evaluation Procedure" . ‪

Mineral ‪	Limit-ppm ‪	Limit -grains per gallon ‪
Chlorides‪	40‪	2.5‪
Sulfates‪	100‪	5.8‪
Total dissolved solids‪	340‪	20‪
Total Hardness: Magnesium & Calcium‪	170‪	10‪

Figure 1. Water Evaluation Procedure

Section 5.4.1.1
Antifreeze, Inhibited Ethylene Glycol

Ethylene glycol is used for freeze protection of the coolant. IEG, commonly referred to as "antifreeze," also contains chemicals that provide a limited protection against corrosion. The use of an IEG product with a low silicate formulation that meets either the GM 6038-M formulation (GM1899-M performance) or ASTM D 4985 requirements is recommended.‪

Section 5.4.1.2
Antifreeze, Inhibited Propylene Glycol

An IPG/water mixture provides freeze protection.‪

Propylene glycol must meet the performance requirements of ASTM D 4985 and the physical/chemical requirements of ASTM D5216. The maintenance procedures for propylene glycol are the same as for IEG. All references to IEG will also apply to IPG for the Series 50 engines. ‪

For best overall performance, a 50% concentration of IEG (1/2 IEG, 1/2 water) is recommended. An IEG concentration over 67% (2/3 IEG, 1/3 water) is not recommended because of poor heat transfer, reduced freeze protection, and possible silicate dropout. An IEG concentration below 33% (1/3 IEG, 2/3 water) offers little freeze or corrosion protection and is not recommended (see Figure "IPG Boiling Point" , see Figure "IPG Freezing Point" , and see Figure "Coolant Freezing and Boiling Temperature vs. Inhibited Ethylene Glycol Concentration (Sea Level)" ).‪

IEG coolants require the addition of SCA to provide cooling system corrosion and deposit protection. The SCA added should match the chemistry of the additive package included in the coolant. If this precaution is not observed, coolant monitoring can become difficult, making over inhibiting more likely. IEG formulations available in the market may contain from zero to the full amount of the required SCA. A basic IEG with no SCA must have additional SCA added at the time of initial fill. A Fully Formulated or Precharged IEG such as Detroit Diesel Powercool ® already contains the required SCA (listed in Table "Powercool ® Fully Formulated/Precharged IEG" ). Over concentration will result if SCAs are added to a fully formulated IEG coolant at the time of initial fill. This can result in solids dropout and the formation of deposits.‪

POWERCOOL ® -DDC Part Number ‪	Size ‪
23512138‪	1 gallon‪
23512139‪	55 gallons‪
23512140‪	bulk‪

Figure 2. IPG Boiling Point

Figure 3. IPG Freezing Point

Figure 4. Coolant Freezing and Boiling Temperature vs. Inhibited Ethylene Glycol Concentration (Sea Level)

Section 5.4.2
Coolants Not Recommended

Methyl alcohol-based antifreeze should not be used in Detroit Diesel Series 50 engines because of its effect on the non-metallic components of the cooling system and its low boiling point. Similarly, methoxy propanol-based antifreeze should not be used in Detroit Diesel Series 50 engines because it is not compatible with fluoroelastomer seals found in the cooling system. Glycol-based coolants formulated for heating/ventilation/air conditioning (HVAC) should not be used in Detroit Diesel Series 50 engines. These coolants generally contain high levels of phosphates, which can deposit on hot internal engine surfaces and reduce heat transfer.‪

Section 5.4.3
Supplemental Coolant Additive

SCAs provide protection for the cooling system components. The coolant must have the proper concentration of SCAs. Detroit Diesel Maintenance Products are recommended for use in Detroit Diesel Series 50 engines.‪

NOTICE:

Excessive amounts of chemicals in the engine coolant can cause a gel-type or crystalline deposit that reduces heat transfer and coolant flow. The deposit, called dropout takes the color of the coolant when wet, but appears as a white powder when dry. It can pick up solid particles in the coolant and become gritty, causing excessive wear of water pump seals and other cooling system components. The wet gel can be removed by non-acid (alkali) type heavy-duty cleaner, Detroit Diesel Maintenance Product cleaner DD-2001 (sodium nitrite/sodium tetraborate). If the gel is allowed to dry, it is necessary to disassemble the engine and clean with a caustic solution or mechanically clean individual components.‪

The proper application of SCA will provide:‪

• A pH control to prevent corrosion.
• Water-softening to deter formation of mineral deposits.
• Cavitation protection to reduce the effects of cavitation.

The proper dosage for initial cooling system fill is listed in Table "Initial Fill SCA Dosage" . Maintenance cooling system fill is listed in Table "Maintenance SCA Dosage" , initial coolant inhibitor element size requirements for IPG and IEG plus water coolant mixtures are listed in Table "Coolant Inhibitor Element Size Requirements-Initial Fill Dosage for IEG or IPG plus Water Coolant Mixtures" . Coolant inhibitor element size requirements, initial dosage for water-only systems, are listed in Table "Coolant Inhibitor Element Size Requirements-Initial Dosage for Water-Only System" . The proper maintenance dosages are listed in Table "Coolant Inhibitor Element Size Requirements-Maintenance Dosage for IEG, IPG, Precharged, and Water-Only Coolant Mixture" .‪

Coolant ‪	Coolant Element ‪	Liquid *‪
Precharged IEG and Water‪	NONE‪	NONE‪
IEG and Water‪	Select Element listed in Table "Coolant Inhibitor Element Size Requirements-Initial Fill Dosage for IEG or IPG plus Water Coolant Mixtures" .‪	3% by Volume, or 1 pint per 4 gallons‪
Water only‪	Select Element listed in Table "Coolant Inhibitor Element Size Requirements-Initial Dosage for Water-Only System" .‪	6% by Volume, or 1 quart per 4 gallons‪

Note: * 1 gallon= 3.785 L; 2 pints= 1 quart; 4 quarts= 1 gallon

Coolant Element ‪	Liquid *‪
Select element listed in Table "Coolant Inhibitor Element Size Requirements-Maintenance Dosage for IEG, IPG, Precharged, and Water-Only Coolant Mixture" .‪	0.6% by Volume or 1 pint per 20 gallons‪

Note: * 1 gallon= 3.785 L; 8 pints per gallon

Cooling System Capacity, Gallons (L) ‪	Quantity ‪	DDC Part Number ‪	NALCO Part Number ‪
9-12 (34-45)‪	1‪	23508426‪	DDF-3000.12‪
13-16 (49-61)‪	1‪	23507189‪	DDF-60.16‪
24-32 (91-121)‪	1‪	23508427‪	DDF3000.32‪

Cooling System Capacity Gallons (L) ‪	SCA Element Quantity ‪	Detroit Diesel SCA Element Part Number ‪	Nalco Element Part Number ‪	Additional SCA Liquid Required ‪
5 (19)‪	1‪	23508427‪	DDF-3000.4‪	None‪
7 (26)‪	1‪	23508426‪	DDF-3000.12‪	None‪
10 (38)‪	1‪	23507189‪	DDF-60.12‪	None‪
15 (57)‪	2‪	23508426‪	DDF-3000.12‪	None‪
20 (77)‪	1‪	23508427‪	DDF-3000.32‪	None‪

Cooling System Capacity, Gallons (L) ‪	Quantity ‪	DDC Part Number ‪	NALCO Part Number ‪
9-12 (34-35)‪	1‪	23507545‪	DDF-3000‪
13-16 (49-61)‪	1‪	23507545‪	DDF-3000‪
24-32 (91-121)‪	1‪	23508425‪	DDF-3000.8‪

The concentration of SCA will gradually deplete during normal engine operation. Check the SCA concentration at the regular intervals listed in Table "Required Coolant Inhibitor Test Intervals" . Additional SCA must be added to the coolant when it becomes depleted below a specified level (listed in Table "SCA Limits with GM6038-M or ASTM-D 4985 (50/50 Coolant/Water Mixture)" ). Maintenance dosage of SCA must only be added if nitrite concentration is less than 800 ppm. If nitrite concentration is greater than 800 ppm, do not add additional SCA.‪

Service Application ‪	Inhibitor Test Interval ‪
On-highway Trucks and Motor Coaches‪	15,000 miles (24,000 km)‪
City Transit Coaches, Pick-up and Delivery, Short Trip, and Emergency Vehicles‪	6,000 miles (9,600 km) or three months, whichever comes first.‪
Industrial, Generator Set, and all other applications‪	200 hours or yearly, whichever comes first.‪

SCA ‪	Minimum SCA ppm ‪	Maximum SCA ppm ‪
Boron (B)‪	1,000‪	1,500‪
Nitrite (NO 2 )‪	800‪	2,400‪
Nitrates (NO 3 )‪	1,000‪	2,000‪
Silicon (Si)‪	50‪	250‪
Phosphorus (P)‪	0‪	500‪
pH‪	8.5‪	10.5‪

Section 5.4.4
Soluble Oils

Soluble oil additives are not approved for use in the Detroit Diesel Series 50 engine cooling systems. A small amount of oil adversely affects heat transfer. A 1.25% concentration of soluble oil increases the firedeck temperature 6%. A 2.50% concentration increases the fire deck temperature 15%.‪

Section 5.4.5
Chromate

Chromate additives are not approved for use in the Detroit Diesel Series 50 engine cooling systems. Chromate additives can form chromium hydroxide, commonly called "green slime." This, in turn, can result in engine damage due to poor heat transfer. Cooling systems operated with chromate-inhibited coolant must be chemically cleaned with Nalcool 2015 cooling system cleaner and conditioner (or equivalent sulfamic acid/sodium carbonate cleaner) and flushed.‪

Some coolant filter elements with magnesium internal support plates have caused engine damage. The coolant dissolves the magnesium and deposits it on the hot zones of the engine where heat transfer is most critical. The use of elements with these plates is not approved.‪

Section 5.4.6
Detroit Diesel Cooling System Maintenance Products

Detroit Diesel Maintenance Products SCA are water-soluble chemical compounds. These products are available in coolant filter elements, liquid packages, and a fully formulated IEG.‪

Section 5.4.7
Coolant Inhibitor Elements

Replaceable coolant inhibitor elements (spin-on canisters) are available in various sizes suitable for cooling systems of varying capacity. If a fully formulated IEG or IPG coolant is not used, a pre-charge element must be installed. Selection of the proper element size is vital when precharging the coolant system at initial fill. If a coolant inhibitor element is used, it is important to make sure that the coolant inlet/outlet valves on the element adaptor head are fully opened prior to filling the cooling system with coolant.‪

Note: A fully formulated IEG or IPG must NOT have SCA added at initial fill.

The need for maintenance elements is determined by the results of the SCA concentration test performed at each cooling system service interval.‪

Section 5.4.8
Supplemental Coolant Additive Test Procedures

Nitrite concentration is an indication of the SCA concentration in the coolant. Nitrite test kits and test strips are commercially available. The coolant must be tested for required inhibitor levels at the intervals listed in Table "Required Coolant Inhibitor Test Intervals" . SCA levels must be within the ranges listed in Table "SCA Limits with GM6038-M or ASTM-D 4985 (50/50 Coolant/Water Mixture)" . ‪

NOTICE:
Do not use Detroit Diesel POWERTrac ® test strips to determine the inhibitor levels of coolant with non-DDC approved additive packages. Incompatible chemicals and variance in inhibitor levels in the additive packages may cause inaccurate interpretation of test strip readings. This can lead to under-inhibiting the coolant, which may result in cavitation erosion.‪

Section 5.4.8.1
Liquid Supplemental Coolant Additive

Detroit Diesel Cooling System Maintenance Procedures SCA and Cleaners are available in liquid form and are listed in Table "Liquid SCA and Additional Coolant Treatment Products" .‪

Product ‪	Size *‪	DDC Part No. ‪
NALCOOL ® 2000-Liquid SCA‪	1 pint (12 per case)‪	23507858‪
NALCOOL ® 2000-Liquid SCA‪	half gallon (6 per case)‪	23507859‪
NALCOOL ® 2000-Liquid SCA‪	5 gallons‪	23507860‪
NALCOOL ® 2000-Liquid SCA‪	55 gallons‪	23507861‪
NALCOOL ® 3000 † - Liquid SCA‪	1 pint (12 per case)‪	23507854‪
NALCOOL ® 3000 † - Liquid SCA‪	half gallon (6 per case)‪	23507855‪
NALCOOL ® 3000 † - Liquid SCA‪	5 gallons‪	23507856‪
NALCOOL ® 3000 † - Liquid SCA‪	55 gallons‪	23507857‪
NALPREP ® 2001 ON-LINE CLEANER‪	half gallon (6 per case)‪	23507862‪
NALPREP ® 2001 ON-LINE CLEANER‪	5 gallons‪	23507863‪
NALPREP ® 2001 ON-LINE CLEANER‪	55 gallons‪	23507864‪
NALCOOL ® 2015, Twin Pac, Dry, Chemical Cleaner/Conditioner‪	2 per case‪	23507867‪

Note: * 1 gallon=3.785 L; 8 pints=1 gallon

Note: † Nalcool 3000 is more compatible with hard water than Nalcool 2000. Use Nalprep 2001 for light deposits. Use Nalprep 2015 for heavy deposits or scale. Nalcool ® and Nalprep ® are licensed trademarks of the Penray Companies.

Section 5.4.8.2
Test Kit Procedures

Use Detroit Diesel Powertrac ® 2-Way Coolant Test Strips (part number 23515917) to measure nitrite and glycol concentrations. Cavitation/corrosion protection is indicated on the strip by the level of nitrite concentration.‪

NOTICE:
Failure to properly maintain coolant with SCA can result in damage to the cooling system and its related components. Conversely, over concentration of SCA inhibitor can result in poor heat transfer, leading to engine damage. Always maintain concentrations at recommended levels.‪

Freeze/boil over protection is determined by glycol concentration. Use the test strips as follows:‪

1. Dip the strip into coolant for one second. Remove and shake briskly to eliminate excess fluid.
2. Immediately compare end pad (% glycol) to the color chart.
3. Sixty seconds (one minute) after dipping, compare the nitrite pad.

For best results make the tests while the coolant is between 50 and 140°F (10-60°C). Wait at least 60, but not longer than 75 seconds before reading the nitrite level. Promptly replace and tighten container cap after each use. Discard unused strips if they have turned light pink or tan.‪

A factory coolant analysis program is also available through authorized Detroit Diesel service outlets under part number 23508774.‪

Section 5.4.9
Summary of Coolant Recommendations

Coolant recommendations may be summarized as follows:‪

HOT COOLANT ‪
To avoid scalding from the expulsion of hot coolant, never remove the cooling system pressure cap while the engine is at operating temperature. Wear adequate protective clothing (face shield, rubber gloves, apron, and boots). Remove the cap slowly to relieve pressure.‪

1. Always maintain the engine coolant to meet Detroit Diesel specifications.

   Note: Propylene glycol meeting ASTM D 4985, and ASTM D 5216 is approved for use in Series 50 engines.

2. Only use water that meets Detroit Diesel specifications. Distilled or deionized water is preferred.
3. The proper dosage of SCA must be included in the coolant at initial fill for all Detroit Diesel Series 50 engines.

   This dosage can be either included in part or entirely in the IEG used, or it may need to be added. Dosage is also dependent on whether water or IEG is used. The user is urged to refer to the full text of this bulletin to determine the proper dosage. Mixing of different manufacturers' inhibitors (SCAs) could cause cooling system problems.‪

4. Maintain the SCA to the prescribed concentration. Test the nitrite concentration by using a titration kit or Detroit Diesel 2-Way Coolant Test Strips. Add SCA only if the nitrite concentration is below 800 ppm.

   Do not use another manufacturer's test kit to measure the SCA concentration of Detroit Diesel Maintenance Products.‪

5. Pre-mix coolant makeup solutions at the proper concentration before adding to the coolant system.
6. Where antifreeze/boil over protection is required, use only ethylene glycol coolant (low silicate formulation) meeting GM 6038-M, GM 1899-M, or ASTM D 4985.
7. Always maintain proper coolant level.
8. A properly maintained cooling system can be operated for up to two years, 200,000 miles (320,000 km) or 4000 hours, whichever comes first. At this interval the cooling system must be thoroughly cleaned and the coolant replaced.
9. Do not use the following in Detroit Diesel engine cooling systems:
   • Soluble oil
   • Chromate SCA
   • Methoxy propanol-base coolant
   • Methyl alcohol-base coolant
   • Sealer additives or coolant containing sealer additives
   • HVAC coolant