BUDAPEST (REUTERS) - Nico Rosberg said he has been working around brake problems all season but Mercedes team mate and Formula One title rival Lewis Hamilton questioned on Thursday how big an issue that really was.

Said Hamilton: "He was perfectly fine on the brakes in the last race (at Silverstone)...I'm just letting you know, because I know the data and he knows you're going to ask me that."

Ahead of this week's Hungarian Grand Prix, the double world champion added his own side of the garage faced no such issues.

"We don't have any problems with the brakes," said Hamilton, a four times winner in Hungary. "Naturally we are always wanting to improve the brakes, particularly in this hot climate where the brakes tend to fade if they get over temperature."

Hamilton, who has won five races this year to Rosberg's three and leads his team mate by 17 points after nine grands prix, was commenting after Rosberg complained separately about the problems he was suffering.

"There are no particular big problems with the car at the moment except my usual issues with the brakes which is a long-term thing and not easy to solve," said the German.

"It is feel, personal feel, it goes back to last season. It's difficult to put right because it has taken so long and we have not had much progress at all," he added.

Hamilton and Rosberg will be aiming for their seventh one-two finish of the season on Sunday while Mercedes can set a Formula One record for going 10 successive races with both drivers on the podium.

Rosberg has never been on the podium in Hungary so far in his career, however. He finished fourth last year after starting on pole position.