Lewis Hamilton's spirits dampened again in Montreal

For a man who came here seeking to regain his team's confidence in his ability, Lewis Hamilton did not seem happy despite running Red Bull's Sebastian Vettel close for pole position yesterday.

In a wet but drying qualifying session, he looked like the only man who was going to improve after drizzle in the final sector slowed drivers on their second runs. Heading into the final corner he was "six to seven tenths" of a second up on Vettel, who had made mistakes that prevented him improving on his first-run lap of 1min 25.425sec. But Hamilton just couldn't get his Mercedes turned into the left-hander at the end of the back straight, and Vettel could breathe again.

"All I needed was to keep a tenth or so, so it was a bit unfortunate," Hamilton said, looking as glum as he had in the bad old days back in Korea in 2011 during his personal crisis. He said he was "still happy to be P2," but didn't look it. It echoed his mood earlier in the weekend, when he had told reporters who picked up on it: "I don't have a downbeat nature. I'm just here to do a job. I don't need to be walking around all happy and delighted. I'm just focused."

This could be something of a watershed race for the two Mercedes drivers. Against expectations, Hamilton has been overshadowed by his team-mate Nico Rosberg in both qualifying and races, both normally Hamilton's fortes. The problem lies in differences in their cars' braking systems.

Hamilton has always been a big fan of Carbon Industrie's carbon brake pads and discs, and used them last year at McLaren in preference to their regular supplier Brembo's wares. Mercedes use CI components but Hamilton has struggled to generate the same feel with them that he had at McLaren.

All of the cars' brakes transfer heat to the wheels and tyres but CI's brakes and pads get hotter faster and the huge heat soak into the wheel and thus into the tyre is thought to be a factor in Mercedes' – specifically Hamilton's – tyre wear problems during races. "This track is all about late braking, and I've always been the latest of brakers, which is why I've been successful here," he said. "But so far I've not been a very late braker this year."

To his relief here he found that changes to small things such as master cylinders and pedal leverage had improved the Mercedes' feel under the heavy retardation necessary from speeds over 300kmh for the first corner and the hairpin, and as far as the driving is concerned has looked good all weekend.

Meanwhile his fellow Briton Jenson Button struggled with gearbox and handling problems on his McLaren to qualify only 14th and Paul di Resta, an excellent fastest on Friday morning for Force India, slumped catastrophically to 17th yesterday.

Hamilton has won on the three occasions that he has finished here, taking his maiden grand prix victory in crushing style in 2007 when he blew away his McLaren team-mate Fernando Alonso, and repeating in 2010 and 2012. But more than that, on his five visits he had never been outqualified by a team-mate. Just to add spice to the situation, Rosberg had never lost out to a partner in his six visits. Until now. Rosberg was fourth yesterday. Self-respect has been at stake.

"Pole was certainly there," Hamilton admitted, "but that's the way it goes. It didn't all go according to the plan. I'm told it's going to be dry for tomorrow, with rain before and after the race, but it could be very tricky." If it's wet, however, that could helpfully cool his Mercedes' hot wheels.

The Anglo-German team continue to race under the shadow of an upcoming FIA International Tribunal which will be convened on 20 June to determine whether they and Pirelli breached sporting regulations by testing in Barcelona recently. Team principal Ross Brawn said on Friday that it was his decision to do that, and admitted that life is presently uncomfortable. "Let's see what happens at tribunal and we'll go from there," he said. "I wouldn't say it is pleasant at the moment but I am comfortable and confident that the facts will become apparent and people can make a better judgement."

If Mercedes lose they could face a fine, deduction of constructors' points or exclusion from races or even the championship. And with McLaren's former technical director Paddy Lowe now officially working with the Brackley team, Brawn might even find his own position under threat.