Mercedes explains Hamilton's pre-race fright in Canada

Mercedes has opened up on what caused Lewis Hamilton's pre-race scare on Sunday in Montreal.

Prior to the start of the race, the Mercedes squad was spotted working on Hamilton's car, with reports filtering through that his power unit has sustained a leak, which was discovered on Saturday after qualifying.

Mercedes investigated the issue and found to root of the leak to be in the throttle actuator as the Silver Arrows battled to ratify the lack of hydraulic pressure.

Speaking on Mercedes' 'Pure Pit Wall' debrief, trackside engineering director Andrew Shovlin explained the situation.

"We dropped the floor and noticed there was some oil on the floor, so somewhere, there was a leak,” he said. “We could also see on the data we were losing some hydraulic pressure.

“The issue is that the cars are then in parc ferme overnight, we are not allowed to touch them or to investigate it further. That investigation moved to Sunday morning, when we are allowed to access the cars again.

“We had to take the power unit out. We traced the leak to the throttle actuator, and then we made a request to the FIA to change the throttle actuator and some of the associated hydraulics.

Shovlin added that it was 'pretty tight' in getting Hamilton's car ready for the start of the Grand Prix - one which Hamilton would eventually win. 

“So, that work was quite a big job though, there’s a lot to do within that. And it was pretty tight to get Lewis’s car back together for the start of the race.

“We are fairly happy we can do the work in that time. The issue when you have an unknown fault or a leak is you don’t know how long it is going to take you to find it.

“We were able to get the car back together. Where we were at risk was if we then fired up and we found another problem, if the engine had to come out again. That’s when we would’ve got short on time and perhaps not even been able to start the race.

"But it was a great job by all the mechanics involved, the car was back together in time and finished the race successfully.”