Read around the forums for years and some people say its not worth it if you aren't towing.

My family did get in an accident years ago in a 2.7L 4runner. Did toyota really make too little brakes and cause a higher chance? I don't know.

I have a 4x4 V6. Should I do the TBU 231mm for DD and not towing? No major cargo, etc.

Just want some feedback.

I did on my Sport more because my daughter was using it in the mountains and I felt better giving her more brakes up front.

Ok thank you.

What about city driving?

Less noticeable,of course, unless you tend to tailgate or stupid people do stupid things in front of you on a regular basis.

for stock conditions in city driving, reduction in stopping distance may be minimal. since the tundra calipers have bigger pistons, there is an improvement in brake torque. the diameter of the rotors are the same so the improvement is small.


improvement is more noticeable when you drive over mountains and when you tow. this is due to the bigger calipers, thicker rotors, & bigger brake pads. you get better brake modulation, less brake pad deposits on the rotors, and less warping of the rotor means less chance of brake vibration

I warped two set of rotors before doing the upgrade. Mostly flat ground, but occasional trip to the mountains - I believe that's when they warped. I did have a really scary moment driving down a mountain - I was riding the brakes too much and they heated up and lost most of their braking power. I barely had enough to pull over and let them cool off. I know that was partially my fault, but if you ever plan to take it too the mountains, I'd recommend it.

I've towed maybe 4 times ever with the 4Runner, I live in an urban area and DD my 4Runner. I did the TBU 5 years ago and never regretted it once. The brakes have more stopping power with less fluid pressure so my ABS doesn't kick in prematurely and try and kill me. Especially in the rain, it's much better.

If you keep your brakes properly adjusted and you are running stock tire size, your brakes should be fine.
I drive in the mountains at least a couple times a month and my brakes work fine.
I almost did the upgrade about two months ago, but I decided to stay stock with new rotors and pads.
If you start going to bigger tires and adding weight like aftermarket bumpers and junk then I think the TBU would be recommended.

Just a word of warming. There is a bunch of us who did the upgrade and seem to have a pretty long push before the brakes firm up. Its like air is in the system. once it firms up its strong but more work than factory.

We may just have the issue of getting air out but ive bleed many times and even used auto bleeders and techstream. Might be a bigger problem with the 2001/2002 models since they have the newer brake pressure unit.

I'm an odd-ball, I honestly can't even find a reason to deviate from stock... and that's TRYING. Don't know if it's only knowing how to drive one way (grew up in Wyoming, learned to drive there from a man who sold insurance and saw lots of crashed vehicles, I don't "ride" the brakes, ever), but even towing a loaded 16' dual axle equipment trailer down a steep (but short) grade, I simply can't find a reason to change. And I *absolutely* don't have ABS kicking on, ever. Wait, I have to go way, WAY, out of my way to make it trigger... driving too fast on a dirt road and absolutely slamming on brakes. It's not like I live in a dry area, Georgia gets a lot of rain and wet roads, braking is never a problem under any conditions I've experience.

For DDing, I'd only ever consider the change if I had to replace the calipers (but I'm a mechanic, I've never replaced a caliper in my life).

If you drive like a reasonable human (not the type who only understands full throttle or full brake), there shouldn't be any reason to change the brakes from a Function standpoint. I suspect most people make the change simply because they want to spend money on some sort of "upgrade" just to say they've done it (or to feel something about themselves). The silent majority (those other 750 million 4-runners that aren't in this forum) have never heard of a TBU and wouldn't spend their money if they had heard of it.


Obviously, mine is only one opinion and it is Just an opinion. There's no right opinion, just yours. Obviously there are a number of people on here who like the change. Of course, walk through any parking lot anywhere and you'll see there are a number of people who think it's perfectly fine to drive around on bald-to-the-cords tires too.

I'm also in this camp. I've had the '97 for 11 years and figured when the brakes needed service I might just go ahead with the TBU. As the years keep going by, it seems less worth the time & money vs. a set of new decent pads. Maybe it's because mine is a 5 speed and I generally downshift to slow vs. going for the brake every time. I'm amazed the clutch is hanging in there with 225k on it (I assume it is since I bought it with pretty decent service records).

That's due to the larger brake caliper pistons. It takes more fluid (you have to push further) to get the same amount of movement from a larger caliper piston compared to the stock caliper piston. Consider your brake pedal a water faucet, the stock caliper pistons a 1 gallon jug and the tundra caliper pistons a 1.5 gallon jug. Because you did not change the faucet out for a larger faucet (a larger master cylinder bore) it's still the same amount of fluid and pressure so it takes longer to fill up the 1.5 gallon jug vs the 1 gallon jug. A larger caliper piston means you get more clamping force with the same volume input. You could also say that a larger caliper piston requires less fluid for the same amount of clamping force.

I am happy with my OEM brakes after I got brake checked on at 80 MPH! I came to a complete stop on the left lane on I-20 within like 2 seconds! No skidding or any thing... I am in fact stunned at how well the truck came to a stop and on it's factory brakes. People complain about drum brakes in the back of tacomas. Nothing wrong in those if you know how to press the brake in an emergency.

My wife warped two sets of stock rotors on her 96 before doing the TBU, then no more issues. So when my 99 warped its first set, I just went ahead and did it as well. No issues in the 70K miles since.

33" tires, regular city driving, occasional trips out west in the mountains.

If you're not warping rotors and having issues like that, then not much of a reason to upgrade. It's not like they stop the truck any faster.

This is something I have been looking into and would like to address at some point. I wonder if a matching tundra master would fit in the 4r?