Accumulator Buzzing Sound Turns on Frequently

I have a 2016 Toyota Fielder hybrid, which is similar to the Aqua. I recently started hearing the frequent noise of the accumulator pump. When I park the car it usually make a sound every 45-60 seconds.

Reading previous posts seems as though the issue is actually the master cylinder and not necessarily the accumulator itself.

However in my home country, most of mechanics change the accumulator alone if this happens. If the master cylinder is what is losing pressure, wouldn't a new accumulator suffer the same fate as well?

Should I just change the master cylinder only or both or do what most people do and change the accumulator?

I haven't gotten any codes as yet. But I don't want to wait too long to ruin what might still be a good accumulator.

Any thoughts on this? Those who have faced this issue, what's really the best course of action?
Would used parts work just as good or just stick with new only? Thanks.