Although Lando Norris held on to bring home a 1-2 in Shanghai, Andrea Stella says the Briton’s alarming brake issue was “unacceptable”.

Running second behind his team-mate Oscar Piastri in the closing laps of the Chinese Grand Prix, Norris reported a brake issue to his engineer Will Joseph on lap 47.

Lando Norris’ McLaren suffered an alarming brake issue

Initially reporting that the pedal was getting a “bit long”, a lap later that was worrying already a “lot longer” with Norris forced to manage the situation.

It became “critical” according to Joseph’s message, Norris’ lap times in the final three falling from the 1:36s to the 1:38s.

Lapping just under three seconds behind Piastri, the issue meant Norris had to brake earlier with almost every passing lap and he dropped six seconds to his team-mate while George Russell closed in on the back of his MCL39.

Norris held on to take second place just two seconds ahead of Russell in McLaren’s 50th 1-2.

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“We had a failure on Lando’s car with the brake pedal that we had to manage over the last twenty laps,” he said.

“Lando and the team did a great job in managing the situation and adapting the driving style to the problem, which then got worse to the point where it put the result at risk, which is unacceptable from a reliability point of view, we need to do better.”

The McLaren team principal revealed that the team knows what caused the problem but wouldn’t disclose it.

“We understand what the problem is, which I can’t disclose for IP reasons,” he told the media in Shanghai.

“But fundamentally, it had to do with a leak in one of the components, not in the brake line, but somewhere else, and the main action required was to limit the peak brake pressure.

“You could brake, but very, very gently. So what was 100-metre braking, became 200 metres, and towards the end, it was 300 metres because Lando needed to lift the throttle, coast to a certain speed and then apply very gentle brake pressure. That was to avoid the leak becoming too fast.

“The brake pedal was going long, and what we needed to do was to avoid the peak pressure, so Lando needed to brake with less and less and less peak pressure.

“It got to the point over the final laps where he was just coasting for a long time, off throttle, and then just applying minimum brake pressure to stop the car and go around the corner.”

Lando Norris’ full radio messages with Will Joseph

Lap 47: Norris: “My brake pedal is going a bit long.”
Lap 48: Norris: “Brake pedal is going a bit long. Yeah the brake pedal has been going a lot longer.”
Lap 48: Joseph: “So if its been going long the whole time, we see it has depth.”
Lap 48: Norris: “It’s not a lot longer, just slightly longer.”
Lap 48: Joseph: “I know. I know mate.”
Lap 48: Joseph: “So I know this is boring but it’s not the brake power that’s changing it’s just the pedal that’s going longer. Limited peak brake pressure into Turn 14 will help, we’re not under pressure, gap to Russell 6.3.”
Lap 49: Joseph: “Lando, the brake pedal will continue to get long.”
Lap 49: Norris: “How big’s the issue?”
Lap 49: Joseph: “It’ll get like half a mil longer per lap. The front circuit will maintain pressure, the rear will lose, but you’ll still get brake power. You just have to be really cautious on the brakes. No risk. Gap to Russell 6.”
Lap 50: Joseph: “So Lando this is one of the things we discussed, I’d rather finish second than not at all. No hard braking. Gap to Russell 7 seconds.”
Lap 52: Joseph: “Lando, five laps to go. The brake pedal is getting worse, you need to limit your brake pressure.”
Lap 54: Joseph: “Three laps to go, the brake pedal is getting longer. At some point it will bottom out. Gap to Russell 9, so limit that brake pressure.”
Norris: “How many laps to go?”
Joseph: “Including this one, three.”
Joseph: “Lando the brake situation is getting critical, so manage peak brake pressures at Turn 6 and Turn 14.”

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