MBE 4000 – Section 5.3 Coolant

Section 5.3
Coolant

Coolant is a mixture of water and antifreeze. Under normal conditions, it is a mixture of 50 percent water and 50 percent antifreeze, but under extreme cold weather conditions, as much as 60 percent antifreeze can be added. For reasons of anticorrosion protection and to raise the boiling point, the coolant must remain in the cooling system all year round.‪

Regardless of mileage, replace the coolant every two years since the degree of corrosion protection gradually drops with time.‪

Section 5.3.1
Fully Formulated Antifreeze

Antifreeze approved for use in the MBE 4000 engine is a mixture of glycol compound (ethylene glycol), and corrosion inhibitors. Antifreeze containing glycol compounds and corrosion inhibitors is known as fully-formulated antifreeze.‪

Note: Do not use propylene glycol.

Fully-formulated antifreeze has the following properties:‪

• It protects the radiator and engine from freezing.
• It provides protection against corrosion and cavitation for all components in the cooling system.
• It raises the boiling point of the coolant. This slows the rate of evaporation, avoiding coolant loss at high temperatures.

Section 5.3.2
Water

Water containing no additives is not suitable as a coolant, even if no antifreeze protection is needed.‪

The water used in the coolant must comply with certain requirements, which are not always satisfied by drinking water. If water quality is inadequate, the water must undergo suitable treatment.‪

The following types of water are preferred for use in coolant:‪

• Distilled water
• Water purified by reverse osmosis
• De-ionized water

NOTICE:
In some areas, tap water can contain high levels of dissolved chlorides, sulfates, magnesium, and calcium, causing scale deposits, sludge deposits and/or corrosion. These deposits can damage the coolant pump and allow the engine to overheat.‪

Section 5.3.2.1
Coolant Specifications and Concentration

To avoid damage to the cooling system, use only an approved corrosion-inhibiting antifreeze. Approved antifreeze must be fully-formulated and comply with the requirements of the Truck Maintenance Council (TMC). Coolant specifications are listed in Table "Coolant Specifications" .‪

Type of Coolant‪	Requirement‪
Fully-Formulated Ethylene Glycol‪	TMC RP-329 Type "A"‪
Water plus Corrosion Inhibitors‪	Temperature Must Not Fall Below 32°F (0°C)‪

When topping off the cooling system after a drop in the coolant level, the concentration of corrosion-inhibiting antifreeze in the coolant must be 50 percent by volume. This affords protection down to a temperature of –34°F (–37°C). The cooling mixing ratio is listed in Table "Coolant Mixing Ratio" .‪

Note: If the concentration is too low, there is risk of corrosion/cavitation in the cooling system.

Do not increase the proportion (mixing ratio) of corrosion-inhibiting antifreeze beyond 60 percent by volume (this gives the maximum antifreeze protection). Further increases in the mixing ratio would reduce the level of antifreeze protection and adversely affect the coolant's ability to dissipate heat.‪

Antifreeze Protection Down to °F (°C)‪	Water % by Volume‪	Corrosion - Inhibiting Antifreeze % by Volume‪
–34 (–37)‪	50‪	50‪
–62 (–52)‪	40‪	The cooling mix ratio is Max. 60‪

Section 5.3.3
Supplemental Coolant Additives for Fully Formulated Coolant

The concentrations of some inhibitors will gradually deplete during normal engine operation. SCAs replenish the protection for cooling system components. The coolant must be maintained with the proper concentration of SCA. Detroit Diesel Power Cool maintenance SCAs are recommended.‪

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. Do not use traditional SCAs with NOAT coolant.‪

The proper application of SCA will provide:‪

• pH control
• Restored inhibitor levels to prevent corrosion
• Water-softening to deter formation of mineral deposits
• Cavitation protection to protect wet sleeve cylinder liners

Section 5.3.4
Recycled Antifreeze

Recycled antifreeze that complies with TMC RP-329 Type “A” (for ethylene glycol) is approved for use in MBE 4000 engines. The antifreeze must be recycled by distillation, reverse osmosis, or ion exchange.‪

Other recycled antifreeze, especially any antifreeze recycled by means of filtration processes, is not approved.‪

Section 5.3.5
Corrosion Inhibitors

Corrosion inhibitors are very important in maintaining engine life. All corrosion inhibitors protect against corrosion caused by acid, and cavitation of wet cylinder liners. SCAs also protect against mineral deposits.‪

The concentrations of some inhibitors will gradually diminish during normal engine operation. To protect the engine, nitrite concentration must be checked at regular intervals, and inhibitors added as necessary. The intervals are longer if NOAT inhibitors are used.‪

NOTICE:
Always maintain inhibitor at the recommended level. Failure to properly maintain coolant with SCA can result in damage to the cooling system and related components. Over-concentration of SCA inhibitor can result in poor heating transfer and lead to engine damage.‪

NOTICE:
Do not mix types of corrosion inhibitors. Do not add additional inhibitors to new, fully-formulated antifreeze, or coolant containing new, fully-formulated antifreeze. This can cause deposits or dropout in the cooling system.‪

The following types of corrosion inhibitors are approved for use in MBE 4000 engines:‪

• Supplemental Coolant Additives (SCAs)
• Nitrated Organic Acid Technology (NOAT) Inhibitors

Corrosion inhibitors are very important in maintaining engine life. All corrosion inhibitors protect against corrosion caused by acid, and cavitation of wet cylinder liners. SCAs also protect against mineral deposits.‪

The concentrations of some inhibitors will gradually diminish during normal engine operation. To protect the engine, nitrite concentration must be checked at regular intervals, and inhibitors added as necessary. The intervals are longer if NOAT inhibitors are used.‪

NOTICE:
Always maintain inhibitor at the recommended level. Failure to properly maintain coolant with SCA can result in damage to the cooling system and related components. Over-concentration of SCA inhibitor can result in poor heating transfer and lead to engine damage.‪

The following types of inhibitor must not be used in MBE 4000 engines:‪

• Soluble oil additives cause poor heat transfer and lead to engine damage.
• Chromate additives can lead to the build-up of "green slime" (chromium dioxide) in the engine, leading to engine damage.

Section 5.3.5.1
Dropout

Excessive amounts of some corrosion inhibitors can cause a gel or crystalline deposit that reduces both heat transfer and coolant flow. This deposit is called "dropout."‪

Dropout takes the color of the coolant when wet, but becomes a white or gray powder when dry. It can pick up solid particles in the coolant and become gritty. It will cause premature wear of the coolant pump seals and other components of the cooling system.‪

The wet gel can be removed using an alkaline (non-acid) cleaner containing either sodium nitrite or sodium tetraborate.‪

If the gel is allowed to dry, it is necessary to disassemble the engine and clean it with a caustic solution, or physically clean the individual components.‪

Section 5.3.6
Non-Approved Coolants

The following types of coolant are not approved for use in MBE 4000 engines:‪

• Antifreeze or coolant containing phosphate can cause dropout, overheating, and damage to coolant pump seals.
• Automotive coolants offer no protection against liner pitting, and generally contain high levels of phosphate and silicate.
• Antifreeze based on methyl alcohol can damage the non-metallic components of the cooling system. They are not suitable for use with diesel engines because of their low boiling point.
• Antifreeze based on methoxy propanol is not compatible with the fluoroelastomer seals used in the cooling system.
• Glycol-based HVAC coolants contain phosphates which can deposit on hot internal engine surfaces and reduce heat transfer.

Section 5.3.7
Disposal

Coolants are biologically degradable substances.‪

When disposing of used coolant, comply with local legal requirements and waste water regulations.‪

Consult the local water supply authorities to determine the best method of disposal.‪

A modern engine coolant has complex tasks to perform. Do not allow any form of "reprocessing" which consists only of mechanical purification.‪

Section 5.3.8
Batteries

Batteries should receive more frequent maintenance and recharging during the cold season of the year.‪

Careful maintenance and low current consumption will help to maintain the full battery charge. Starting capacity drops severely in cold weather. For example, at 14°F (–10°C) starting capacity is only about 60 percent of normal. If the engine is shut down or out of use for an extended period of time, store the batteries out of the vehicle in a heated area if possible. Ensure good ventilation when recharging.‪