Anybody have any idea what could be causing this? I was thinking master cylinder. Would a toyota part work & from what model?

Lexus part is $1200, trying to save some money here,

Any suggestions?
Thanx

 

the first thing i would do would be to cycle out all of the old brake fluid, replacing it with new fluid and then bleed the system. if that doesnt fix it then i would rebuild or replace the master cylinder.

a rebuild kit replaces all the software within the cylinder, which makes it as good as a new one.

the trick to getting parts for cheap is finding out the part number and then looking it up the internet
until you find it cheapest.

a re manufactured BMC is about $130 on rockauto.com

 

Thank you so much!, This is my 1st Lexus And I do not know too much about these cars.

Have a great day!