ABS Module? Brake Booster?

i have a 2015 Toyota Tacoma that has been giving me brake issues as of late. Pedal feels mushy when the truck is started but firm when the truck is off. Which also tells me my brake booster is working fine. ABS light or engine lights don't show. Took it to a brakes plus and they said I needed a new master cylinder. I Put the new master cylinder on, bled the brakes like 5 times and still mushy. I am also hearing a air leak noise when I push on the brakes coming from the passenger side under the hood. I'm thinking it might be coming from inside the abs module which I hope is not the case. Has anyone else incountered this problem? Anyone worked on these modules or heard of such a thing?

 

You need to bleed the abs module. Scanner is required

 

This ^^^^^^^^^^^^^^^^