Firefighters responded to a callout affecting traffic on the Goulburn Valley Hwy on Wednesday morning.
The trailer of a truck caught fire near Congupna at around 10.10am, with multiple CFA and FRV units working to put out the blaze - as well as a patch of grass next to it, which also caught alight.
Firefighters on scene said the truck was heading north when a fault in the brake line caused the trailer to catch fire.
The driver, who was not injured in the incident, was able to detach the trailer from his truck.
The trailer was completely destroyed, but the cabin of the truck was undamaged.
Southbound traffic on the highway was stopped for over 30 minutes, while northbound traffic was being diverted down Katamatite-Shepparton Main Rd.
The fire was out by 10.40am, and the highway was back open in both directions by 10.50am under further traffic control.