Brunner's constitution was considerably impaired by his exertions and his health never fully returned. Despite this, after a period of recovery he set out in November 1848 with three companions, including Kehu, to discover a quicker route between Nelson and Wairau. This involved travelling the paths of the Maitai and Wairoa Rivers to their headwaters. The weather was poor throughout the six-week trip and Brunner was in discomfort for much of the ultimately unsuccessful venture, which determined that the existing route to Wairau was the fastest.