A1 ADAS Group says manufacturer procedures risk being overlooked when
coolant systems are disturbed during EV and hybrid repairs
Bodyshops are being urged to pay closer attention to manufacturer coolant bleeding procedures on electric and hybrid vehicles after A1 ADAS Group encountered cases where incorrect bleeding resulted in vehicle recovery and avoidable rework. Jamie Willis, Business Development Director at A1 ADAS Group, said the company is carrying out more EV and hybrid coolant bleeds through its mobile technician service and believes the procedure is being overlooked during the repair process.
He recently came across a nearly new hybrid Mercedes where the coolant had been topped up following repair work, but the required bleeding procedure had not been completed correctly before the vehicle was returned to the customer.
A warning light subsequently appeared and the vehicle had to be recovered to the repairer, leaving the customer stranded and requiring alternative transport. The vehicle then needed further work to rectify the problem.
Jamie said: “On the face of it, bleeding a coolant system sounds like a relatively simple job, which is probably part of the problem. On many EVs and hybrids it isn’t simply a case of topping up the coolant and allowing it to circulate.
“You have to follow the OE method for that specific vehicle. Depending on the manufacturer, that can involve an OE diagnostic tool alongside specialist pressure or vacuum filling equipment. Diagnostic equipment may also be needed to operate pumps and valves within the cooling circuit.
“Simply topping up the coolant and relying on gravity doesn’t necessarily remove air trapped within the system. We’ve had vehicles where the bleeding process has had to be carried out several times before all the air has been removed.”
A1 says specialist coolant filling equipment and procedures have traditionally been more familiar to mechanical workshops, but bodyshops are now encountering them as part of EV and hybrid accident repairs.
Jamie continued: “Repairers are very aware of the checks around areas such as ADAS, paint and quality control, but coolant bleeding isn’t necessarily receiving the same attention yet.
“A warning light and a vehicle coming back still means an unhappy customer, recovery costs, lost workshop time and rework. At the more serious end, an incorrectly filled cooling system can result in overheating and potentially much greater damage.
“The important thing is to identify at the estimating and repair-planning stage whether the vehicle requires a specific coolant bleeding procedure. That way it becomes part of the repair rather than something discovered after the vehicle has gone back to the customer.”
A1 ADAS Group’s UK-wide mobile technicians carry OE diagnostic tooling and specialist equipment to undertake coolant bleeding in accordance with manufacturer procedures, alongside ADAS calibration, diagnostics, coding, EV shutdown and power-up and wiring repairs.
