Based on the preceding SR 113 Bucegi of 1962 but powered by a 99 kW (133 bhp) 6-cylinder Saviem diesel engine, the truck could carry a payload of 6,000 kg (13,228 lb).

'Red Flag' named in honour of the Communist movement, introduced a 5,000 kg (11,023 lb) truck made in their factory in Brașov.

The truck soon became popular, both as a general transport for goods, and in more specialised roles, including as a mobile workshop to support urban tram and trolleybus networks.

Improvements were made in 1980, when non-structural steel parts of the design, including the hood, were replaced by plastic, saving 1,000 kg (2,205 lb) in weight.

[3] Production was to cease with the introduction of the 8135 as a replacement in 1985, but the popularity of the truck meant it was still manufactured, although in smaller quantities, throughout the decade.

[6] Exports continued after the Fall of the Berlin Wall, increasingly to Western countries like Germany and the United States, but against greater competition from more advanced products.

[7] In 1990, the manufacturer, now known as Roman, continued small scale production of the 6135 without change under the original brand DAC.