An Audi spokesman said that the recall affected the company's A4, the A5, the A5 Cabrio, the A6, the A7 and also the Q5 crossovers models built between March and December 2012.
The models were fitted with the 3.0 litre TDI turbo diesel engine.
The problem had been found within the brakes as the engine oil could enter the brake servo through the vacuum lines and make it rupture, causing failure, Audi explained.
This would eventually increase the stopping distance and pose a potential hazard to the driver, occupants and other road users.
The problem could be fixed relatively quickly and easily, the carmaker said.