Nearly five out of every six petrol and LPG tankers tested at Cootes Transport have again failed safety inspections causing the troubled trucking company to "voluntarily" ground its entire fleet.
VicRoads tested 32 tankers and trailers at Cootes' Spotswood depot on Friday and found 25 had major safety faults.
Fuel scare after tanker fleet grounded
There are fears over the supply of fuel after a fleet of Cootes petrol tankers were grounded due to safety concerns.
The road authority intends to test 200 petrol and LPG Cootes vehicles.
VicRoads acting chief executive Peter Todd said the authority had had a "serious discussion" with Cootes and it had "voluntarily" decided to ground its 200-vehicle fleet in Victoria.
Cootes has come under fire after a crash in Mona Vale in Sydney caused a safety check blitz in Victoria and NSW. Cootes was issued with hundreds of defect notices. Two people were killed and five injured in the crash.
VicRoads will begin more safety checks at the company's Dandenong depot on Sunday.
The faults found in the Cootes vehicles included brakes, shockers, air bags, loose bolts and oil leaks.
Mr Todd said the 32 vehicles had also been tested in October when snap inspections were carried out. He said the vehicles had also been found to be faulty at that time but the faults discovered this week were new.
"It appears to us that there is not enough being done – that seems to be the evidence of what we have found," Mr Todd said.
"They were repaired and we were sure they were repaired.
"They are working and they are travelling significant distances but they do need to be maintained. At everytime they need to be safe.
"Road users in Victoria can be confident that the vehicles on our roads are safe.
"It is this situation here that we are finding very disturbing with this company and that is why we have an ongoing regime of inspections."
The latest inspections were brought forward after NSW road authorities found serious faults in eight out of 15 Cootes Transport vehicles last week.
Mr Todd said fuel companies had indicated that they had enough fuel over the weekend and he called for the public not to panic buy petrol.
He could not say when inspections would be complete but said they would be more frequent in the future.
He said fines would be considered but the grounding of the fleet was a significant penalty.
The defects have cost the company dearly. Transport giant Toll has snared a five-year fuel transport deal with Shell worth $250 million, from Cootes Transport.