Maintenance of Diesel Engine Coolant Systems

It is estimated that the failure of an engine coolant system is one of the key factors for the engine downtime. The diesel engines today emit more heat than their predecessors, requiring better cooling mechanisms than ever before.  They require a fully formulated, premixed, glycol based coolant containing a heavy duty additive package and de-ionized water. The coolants play an integral role in the system maintenance. They have to face multiple conflicts with rust, acid, foams, debris etc. to maintain the right operating conditions of an engine. Coolants may differ according to the job and requirement. They need to be monitored frequently to ensure proper chemical balance.

No engine cooling system can be maintenance free. Every component degrades over time and so does the coolant. Various factors such as dilution with water, additives and the invasion of foreign particles entering the cooling system, can all cause a chemical degeneration. Products can get mixed, making testing and servicing difficult.

A coolant can perform well only when it preserves its original composition. The mutated version can cause fluctuations yielding disastrous results for an engine. Fleetguard Filtration provides the most comprehensive cooling system product range with support products that help test, service, and repair cooling system fluid. Mentioned below are various ways in which a coolant system can be taken care of in order to experience less downtime & great efficiency.

Coolant Filtration

A coolant filter is a primary mechanism to remove contamination that enters the cooling system through poor quality water, internal component wear or other inbuilt particulates which are a key cause of pump seal failure. Coolant filters are the most effective solution against contamination of the coolants and are essential to service your coolant and protect it.

Test Strips

Using test strips is like the litmus test used to correctly determine the condition of the coolant. Regular testing can identify trends that may be leading to equipment damage. These strips help determine various factors such as

  • Overall freeze protection and key inhibitor quantity levels.
  • Overall Quality of the coolant to determine whether it is fit for continued use or is contaminated.
  • Water Quality - is this water suitable for use in a cooling system.


Depleting glycol levels in the coolant will bring down the boiling point and have a detrimental effect on the engine, especially in hot spots around the head. Refractometers are a near accurate tool to measure the glycol content of engine coolant. It is essential to maintain glycol levels within the specified limits. Different products may require different refractometers depending on their additive makeup.

Fleetguard Coolant Solutions

There are many products available in the Fleetguard range to assist with Cooling System maintenance:

  • • Ethylene Glycol (EG) and Propylene Glycol (PG) based Fully Formulated Coolants (ES Compleat)

These glycols are available as pre-mixed products, using de-ionized water, which are ready to use. They are also available in the more traditional, concentrated format which requires dilution with good quality water before use.

  • • DCA (Diesel Coolant Additive) heavy duty corrosion inhibitor

These inhibitors are available as a liquid concentrate to allow initial charging of a standard antifreeze product or to re-charge. A coolant which is low in inhibitor levels.

  • • Cooling System flushing/cleaning agents to remove scale, corrosion products, oil and gel contamination etc. Radiwash This not only removes contamination /scale/rust in the intricate passages of the engine without need of dismantling but dramatically brings the engines at operating temperatures.

Fleetguard is one of the leading Automobile Filter Manufacturers in India.

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