HOUSTON, Texas — A recommendation to drain the low-pressure fuel filter on natural gas engines each day, if ignored, can prove to be a costly mistake.

That was the warning from Chris Nordh, senior manager, alternative fuels and finance with Ryder, when speaking at the Natural Gas Fleet Vehicles North American Congress. Nordh said one entire 16-truck natural gas fleet was put out of service for months after experiencing oil intrusion at a reputable fuelling station. Every component of the fuelling system had to be removed and cleaned or replaced, including the fuel tanks, fuel lines and gas flow sensors.

The issue was caused by the fuel supplier using an incorrect compressor oil, which was then passed into the trucks’ fuel system.

“This is a serious issue and it can cause some troubling maintenance-related issues,” Nordh warned.

The best way to prevent this from happening is to drain the low-pressure fuel filter daily and inspect it for any signs of oil, Nordh suggested.

“Have drivers drain that low-pressure fuel filter every day, because once this happens, that’s the first place it’s going to show up,” he said. “Especially if you are using different fuelling stations, this can identify which ones are passing oil through.”

Nordh said the fuel supplier and Cummins both went above and beyond to get the fleet back up and running but it took an enormous amount of work and time.

“It was an incredible experience to see what can happen when oil is passed in through the fuel stations,” Nordh said.