Further faults have been found in vehicles operated by trucking company Cootes whose petrol tanker was involved in the Mona Vale explosion killing two motorists last October.
More than 30 trucks owned by the national distributor were inspected on Friday by VicRoads officers and major defects were found in 25 including problems with brakes, shock absorbers, air bags and loose bolts.
The Victorian grounding follows similar problems in its New South Wales fleet revealed last week with Roads Minister Duncan Gay ordering all Cootes petrol and gas tankers to return to the state for a full compliance inspection after more incidents involving their vehicles.
The latest technical headache comes as senior management for McAleese, the owner of Cootes, work through the weekend ahead of releasing a statement to update the market before the stock exchange opens on Monday.
The company's stock went into a trading halt on Thursday as McAleese revealed it had "progressed" a review of its Cootes business.
Cootes is being restructured following the loss of fuel haulage contracts with long-term customers Shell and BP last month, the AFR reported Friday.
A statement released on Saturday said Cootes Transport proactively began operational and safety inspections of its Victorian fleet last night by independently authorised inspectors.
"Cootes Transport continues to work cooperatively with both state and federal regulators in relation to issues with its fleet, which includes making vehicles available for inspection," it said.
"We are working closely with regulators to address issues within the fleet while maintaining supply of essential services across the country.
"Regulators have been fully briefed on the steps being taken by McAleese to remedy any issues which include the appointment of independent safety experts, voluntary inspections and a significant investment in new vehicles.
Cootes said it was too early to say whether the grounding of the vehicles in the Victorian fuel transportation fleet would affect supplies and said it would depend on reserves held by retailers."
Minister Gay said Monday the action calling for NSW tankers to return to the state for a full compliance inspection followed spot checks of Cootes vehicles the previous week including 35 inspections at Wetherill Park and Port Botany which resulted in 17 vehicles with major defects immediately ordered off the road for repairs.
"These random inspections uncovered significant failures. This was in addition to two incidents involving Cootes vehicles late last week which presented major defects,” he said.
"While we acknowledge there have been some improvements in the fleet, it is simply not good enough that in some cases we have seen repairs that don't meet our standards during a second or third check.
“Despite four months of ongoing work with Cootes and the parent company McAleese, I have ordered all their NSW tankers be subject to Roads and Maritime compliance checks yet again – just as we did immediately after the Mona Vale tragedy.
“I want to assure motorists we have been carrying out extensive inspections and random checks of this fleet since the tragic double fatality on Mona Vale road last October."
Since October 2013 the company says it has spent an additional $5 million on repairs and maintenance of its vehicles.