By 1 February 2007, 38 three-car sets were withdrawn due to continuing braking failures, meaning that more than half of the Siemens Nexas fleet (or around 10% of the total fleet) was out of revenue service. Amidst the media reporting an escalating problem with the risk of the entire fleet potentially having to be suspended, Siemens issued a statement on 31 January 2008 saying that they believed there had been no evidence during investigations of the braking failures that would require the entire fleet of trains to be withdrawn from service. Testing of affected trains was carried out on the Werribee line between Newport and Laverton, with soapy water sprayed onto the rails to increase the amount of wheel slip experienced, in an effort to replicate the brake fault. The entire fleet has now re-entered service, although with a restriction not to run single unit (3 car) operations.