Complex sentence: Another improvement the Lotus Cortina gained was the new braking system (front discs) which was built by brake specialist Girling, this system also was fitted to Cortina GT's but without a servo which was fitted in the Lotus Cortina engine bay.
Split into simpler sentences: Another improvement the Lotus Cortina gained was the new braking system (front discs) which were built by brake specialist Girling. This system also was fitted to Cortina GT's but without a servo, which was fitted in the Lotus Cortina engine bay.