When drivers call in reporting the loss of power, excessive white exhaust smoke and engine misfiring combined with erratic idling, the most probable reason is water in the diesel fuel system that has bypassed water traps.

Hennie Botha, Director Fleet at Key Hire, comments – “Major KZN reservoirs such as Midmar and Inanda are running over 80% at the start of the rainy season, indicative of good rains and possible contamination of diesel storage tanks.”

Replacing water-damaged fuel injection equipment is a very costly exercise. “We cannot afford to get lax on the disciplines that minimise H2O contamination,” says Botha and continues – “Countermeasures are not seasonal; it is an ongoing process.”

Fix the cause and not the symptom

A clearly written fuel policy is a good starting point. The policy sets the standards, specifications, procedures, and training required to control the purchase, storage and dispensing of fuel supplies. Without the benchmarks set in a fuel policy document, there can be no way of enforcing discipline – ‘If you can’t tell me what to do, and how to do it, then anything goes,’ observes Botha – “Replacing fuel injection equipment is a very costly exercise.”

Botha offers the following suggestions that should not only be in the fuel policy and procedures document but should form part of daily operational procedures. Here is a useful checklist:

1. How does water contaminate diesel?
  1. Water gathering by means of rainwater seeping into underground bowsers
  2. Moist outside air entering tank vents resulting in condensation
  3. Existing low water content in fuel gathering in low spots of the vehicle fuel system, bypassing a full water trap filter
2. How to detect water contamination
  1. Water tablet test
  2. Water paste test
  3. Wear Check Fuel Analysis
  4. Visual Indications
3. How to avoid water contamination
  1. Avoid filling up when the service station is refuelling
  2. Adhere to OEM service intervals
  3. Use a fuel stabilizer in bowsers
  4. Dedicated fuel storage containment
  5. Don’t stretch your fuel – don’t fill up on empty
  6. Drain water traps regularly

Botha concludes:
Purchase fuel from reputable suppliers to a guaranteed specification – in this case SABS 342 covers the quality of diesel fuel…..but:
1. Install good housekeeping procedures – cleanliness, drainage, secure sealing of inlet valves, breathers that are unclogged and do not draw in contaminants.

2. Check the fuel tanks for water just before, then sometime after bulk delivery.

3. Ensure that the fleet, regardless of age, is equipped with water trap separators. Modern trucks, even down to the small GVM units are equipped with water trap separators and warning lights on the driving console.

4. Train drivers and maintenance staff on the importance of ensuring that water trap separators are attended to regularly, and what warning lights are saying. Don’t neglect this until a breakdown occurs.

5. Keep fuel tanks filled up when parking vehicles overnight. The condensation that forms in an empty diesel fuel tank at night with the drop in temperature is a problem in some areas.