2020 Nissan Frontier Master Cylinder brake fluid removal

[vic831]

Forgive me if this has been covered, I ran a search first. I’m doing a brake fluid exchange on my 2020 Frontier. I want to get most of the fluid out of the MC first before adding new fluid and bleeding the lines by gravity. The problem is the access thru the top is very restricted. I have access to medical suction tubing about the size of IV tubing and a 60cc
Lure lock syringe that I can thread down with difficulty but about 1.5 -2 inches of old fluid remains at the bottom closer to the firewall.

Does anyone know why the access at the MC cap is so limited? And how does the service department evacuate the old fluid, if there a drain somewhere I don’t see??? Thank you to everyone for any advice.

[VStar650CL]

Most service departments use a machine that sucks from all four wheels simultaneously and doesn't require draining the reservoir, you just add new as the old stuff is sucked out. There's no circulation in a brake system, so the bottom of the system is where the fluid really gets crappy. Brake fluid is hygrophilic, but water molecules will still gravitate (literally) to the lowest points. When flushing, replacing what's in the reservoir is a lot less critical than removing the junk sitting in the calipers.

[vic831]

VStar once again man thank you for the inside info.
Just an unnecessary design by Nissan to make it very
difficult to fully evacuate the master before starting the flush with new fluid, obviously to prevent or discourage DYI service ….. but not me.

[VStar650CL]