Although it was not the first operator of Reliances in Australia, the Department bought 120 over twelve years — the largest fleet in the country. Canberra’s first Reliance arrived in April 1956 and was the forerunner of 52 similar buses, with bodies by Commonwealth Engineering, over the next five years. One of these vehicles, number 037, which entered service in December 1960, was fitted with air bag suspension, one of the first city buses in Australia so equipped. Unfortunately the Department felt that this pioneering attempt at improving the quality of the ride of buses was not altogether successful as the manufacture of reliable air levelling valves had not yet been perfected. Canberrans had to wait until the arrival of the Leyland Nationals in 1974 before again experiencing the comfort of air suspension.
Leyland’s medium weight chassis, the Leopard, was introduced at the end of 1959 and the first models reached Australia in 1961. Although a couple of Sydney private operators bought examples in 1961 and early 1962, Canberra was the first Government concern to buy a Leopard. Number 015 was registered in August 1962. Only 11 examples of this marque were bought, because the AEC competitor, the Reliance, was preferred.
The Reliance with AH470 engine, was, in the main, a reliable medium weight chassis. For an underfloor-engine bus it was generally quiet, gave a good ride and was economical. However, frequent failure of the heaters was a severe inconvenience in the Canberra winter.