ive been having problems with my brakes since i bought my new 4runner and ive narrowed it down to the brake master cylinder. i plan on running to a junkyard this weekend for tundra rotors and pads to upgrade my front brakes in my 4runner. i read online that for first and second generation 4runners their master cylinder can be swapped for an fj80 master cylinder. is there a larger bore brake master cylinder i can pull off a tundra or other toyota that i can easily swap into my 4runner to not only replace but upgrade mine?

 

while im on the subject, is bench bleeding required if i was to just pull a master cylinder off my parts 4runner and put it onto my 4runner with the spongy brakes?

 

IMO you will need to bench bleed your mc. Also you'll want to buy a rebuild kit for it. If your going through the motions to remove and replace....make the mc as new as possible. Used parts are an unknown! When you have the mc off use compressed air to blow the rubber piston out. You can clean the mc with soap and water as brake fluid is water soluble. When dry look at the inner bore of mc for scoring, rust, pitting and etc. If all is good install your rebuild kit and bench bleed. If the mc shows any of the above imperfections don't use it! Just swallow hard and buy a new one. Honing is not recommended as the metal is very soft and the rebuild kit will not hold pressure anymore. Install and bleed the system. You can start bleeding at the master by cracking the line fitting and than moving to the furthest wheel and moving closer and closer. Hope you have a power bleeder.......and hope this is helpful.