The crash happened around 2:40 a.m. near Riverside Avenue. Officials said the tanker spilled about 1,000 to 1,500 gallons of fuel onto the freeway, but there was no fire. The truck driver was taken to a hospital for minor injuries.
Westbound lanes were expected to be closed for several hours as crews clear the scene. Drivers were urged to take Valley Boulevard or the 210 and 60 freeways to avoid the mess.
The cause of the crash remains under investigation.