Hey mates,
Please be accurate in your questions and answers.
767 accumulator is not for stopping the aircraft
if you had lost all hydraulic pressure?
The brake accumulator is the last kettle than contains hydraulic pressure to actuate the brakes, so, in certain circumstances it will be the last source usable for stopping the aircraft (that principle goes for any type of airliner).
Brake systems are usually powered via 2 hydraulic systems (normal and alternate), out of the 3 hydraulic systems that are often available in airliners.
So, on the 767, CTR and R HYD SYS FAIL would leave you with accumulator pressure only for the brakes, while safely landing the aircraft would be done on L hydraulic pressure.
Accumulator pressure should be enough to bring the aircraft to a stop out of a landing. Every application of brakes taps pressure from the accumulator, so don't pump the brake pedals and don't brake so hard that anti-skid releases brake pressure for you. Try to make one steady brake application.
After stopping on the runway, do not taxi further, counting (on) the number of applications that some expert on PPRUNE once gave you.