3rd gen 4Runner pedal to the floor after tundra caliper upgrade

Okay so my wife’s 2000 4Runner 4x4 limited doesn’t want to stop. It will stop but the pedal goes to the floor and then it will stop a couple seconds after. I changed the master cylinder calipers and put SS lines on there. And supposedly In 2019 the previous owner had a new brake booster installed. I bled the lines 2 times no air in the system and visable leaks I coils find

I did install 2005 tundra calipers and rotors. But it was doing this before hand. That’s why I got the bigger brakes cause I was gonna change everything . I got the Same set up on my 03 double cab and it works amazing.

I am stumped on what it could be. Amy thoughts?

 

Still air in the system somewhere is my thought. Did you bench bleed the new master cylinder? I'm assuming you have bled brakes before and started at passenger rear, then driver rear, passenger front, driver front? Is there a BPV valve in the rear like the 1st gen Tacomas? Usually best to bleed that first and then go to passenger rear, so on and so on.

 

Ya bench bled the master cylinder before I installed it no air in that for sure. I have to looks and see if there is a BPV valve. I had to do that on my Tacoma. I started at the right rear then left rear front right front left. I’m pretty pretty sure there is no air in the system.

 

Is a 2000 limited. I can’t find a lspv valve. Pretty sure it doesn’t have one

 

So update. Cleared abs of bubbles. It actually would stop now but still only engage at the floor. Extended the throw of the booster also Mechanic looked at the drums cleaned em out adjusted the shoes and e brake and bled the system again. Still same thing. It ended up being the power brake booster. Previous owner had had it replaced and the guy who did it for him installed a Tacoma booster not the 4Runner which was a whole inch and a half shorter throw that the 4runners. That was causing the pedal to not engage until the floor. Replaced every single part on the brake system except the booster because because it was done last year . Stops like a dream with the correct booster in there. Definitely a must do upgrade on any of these trucks.

 

So tundra brake upgrade and stock booster worked out good, way better than stock??

 

oh ya for sure!! Much more pedal grab. It starts right when you touch the pedal. You do need to bleed them good and get any air out of the abs system and I do have SS brake lines all around which I recommend too. A definite upgrade for sure. I got the calipers and power stop tow pads and slotted rotors on Amazon for like 350 bucks. 2005 tundra stuff with 13wl cast calipers. On my Tacoma the upgrade is even better. And I have a crap load of weight on my truck. I think the master cylinder design is a little better in the 2003 Tacoma’s.

 

Thanks for the tips

 

gotta have 16’ rims or bigger to clear the calipers FYI. There are lists on the internet for what will fit