4WD MODIFICATIONS - POWERTRAIN
We’ve used various types of water separators in all our 4WD vehicles and the latest we’ve bought is the best so far.
Water can find its way into your 4WD’s fuel tank in various ways, including leaking service station tanks that admit ground water, condensation in drums or above-ground storage tanks and condensation inside your vehicle fuel tank.
Another common source of water inside a ute fuel tank is rainwater pooling on top of an under-tray tank’s fuel gauge sender or fuel pickup, via holes in the cargo tray.
Only a minute amount of water is sufficient to cause severe damage to modern 4WD fuel systems and the standard filters fitted to these engines are not designed to screen out water. Additional water-separating capacity is needed.
Until recently we’ve used a simple water-stop unit to successive vehicles, transferring it from one to the other at trade-in time. This unit had a glass bowl, housing a float that sank in diesel and floated in water, thus blocking flow to the fuel filter when it filled with water. Because it was well-used, after being fitted to four 4WDs over the past 15 years, we decided to buy a new one. We checked out the available units and settled on a Water Watch that cost us $495.
That may seem a lot of money for a water-separator, but we know from experience how many times we’ve encountered water-contaminated fuel. Repairs to an older-style mechnical-injection sytem are still many times the cost of a Water Watch and fixing a common-rail system can be seven grand or more.
The makers claim that the design causes no restriction to fuel flow in modern common rail systems and can be fitted to virtually any vehicle. The housing has a screw-on glass bowl and a drain cap at the bottom, and there are bracket kits available for most popular 4WDs.
The Water Watch wasn’t difficult to fit in our LandCruiser ute’s engine bay, upstream of the standard fuel filter. It came with a wiring loom and a dashboard light and warning siren.
When the ignition key is turned the light and siren are activated briefly, indicating that the Water Watch is working. If water is sucked into the bowl when the engine is operating the light and siren warn the driver that there’s contamination in the system.
We didn’t have to wait long to check out the unit’s capability, because we picked up some dodgy fuel while doing a Kumho tyre test in western NSW. The alarm went off and we killed the engine immediately.
In the bowl a tiny amount of water showed up as a silver layer – looking almost like mercury. We unclicked the electrical plug at the base of the unit and unscrewed the drain cap to let the water flow out. Then we tightened the drain cap, reconnected the electrical plug and away we went. The whole operation took around five minutes.
We like the Water Watch very much and look forward to its fuel system protection, hopefully, for the next 15 years!