Drivers are being told they do not need to panic-buy petrol after the grounding of trucking company Cootes' Victorian fuel transport fleet.
The company voluntarily agreed to immediately ground its fuel and LPG fleets over safety concerns, only days after a third of its large NSW operation was ordered off the road when major defects were detected.
VicRoads officers inspected 32 trucks and trailers on Friday and found major defects in 25.
Safety checks on fuel tankers revealed defects in brakes, shockers and air bags and loose bolts and oil leaks.
"(Friday's) inspections are disappointing, however Cootes Transport management has agreed to immediately ground their fuel and LPG fleets voluntarily and will have all vehicles independently inspected for roadworthiness," VicRoads acting boss Peter Todd said.
Despite the disturbing development, Mr Todd said there is no need for Victorians to panic-buy petrol.
"We've got some advice that there will be plenty of fuel in Melbourne and in Victoria," he told reporters on Saturday.
"People shouldn't panic, they don't need to rush out and buy. Just take it as business as usual."
Last October, VicRoads grounded Cootes prime movers and trailers for severe defects during a sweeping fleet review prompted by a fuel tanker explosion in Sydney that killed two people and involved a Cootes vehicle.
Cootes' had advised VicRoads it had improved its maintenance regime significantly since the October audit.
But the fresh audit, sparked by the company's NSW grounding on Monday, found some of the vehicles audited last October were again found to have defects, although for different reasons.
"It appears to us there is not enough being done. That seems to be the evidence from what we've found over the past day or so," Mr Todd said.
Cootes' entire Victorian fleet of more than 200 vehicles will be inspected, with further checks on Sunday at the company's LPG facility at Dandenong.
Mr Todd said none of the vehicles will be allowed back on the road until they are safe.
VicRoads will consider more regular audits, significant financial penalties and the company's ongoing accreditation, following the inspections, he said.
About 400 of the 1200 trucks in Cootes' NSW fleet were pulled from service on Monday.
NSW Transport Minister Duncan Gay ordered full compliance inspections for all fuel and LPG tankers in the state after spot checks identified major defects in 17 vehicles.