Just a couple of hours before Sunday's Canadian Grand Prix it was revealed that Mercedes had been forced to strip down Lewis Hamilton's car that morning following a hydraulics scare.

In the latest Pure Pitwall video, trackside engineering director Andrew Shovlin, reveals the issue first became apparent after qualifying.

"We had some issues with Lewis's car before the race and this actually became apparent after qualifying," he says. "We dropped the floor and noticed there was some oil on the floor, so somewhere there was a leak. 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," he continues, "so we are not allowed to touch them or to investigate further. So, that investigation moved to Sunday morning, when we are allowed to access the cars again, and the mechanics can work on them.

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

"So, that 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.

"While 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, to identify 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 have 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 and happily the car was back together in time and finished the race successfully."