[Jetboy]

I have warped rotors and need new ones. The braking power is just fine. I have no issues stopping. Either way I'm swapping in a tundra set. I've already got the calipers and rotors, so all I need are pads and a few odds and ends. I plan to do it this weekend.

So here's my question...

Why? Why do tundra brakes work better? The rotor is no larger in diameter. It is wider by lets say 10mm (although I think it's closer to 4-5mm). So let's say it's roughly 300mm in diameter, that means that there is a grand total of roughly 180sq cm of added area to dissipate heat. The disk area alone, not counting any heat dissipated into the hub wheel etc, has roughly 4370sq cm of surface area. The calipers appear to be identical with the exception of having a wider center slot for the wider rotor. So at best the tundra rotor is adding 4% increase in surface area. And the brake pads appear to be interchangeable although the tundra ones seem to have larger pad area.

Anyway I think it's fair to assume that the brakes will generate the same total thermal energy in a given stop (it has to if it's converting kinetic energy to thermal..). So taking that as a given, why are tundra brakes so much better? A 4% increase in surface area? Or is it just the thicker rotor can absorb more heat and keep the average disk temperature down?

So, why do tundra brakes work better?

[cackalak han]

Yes, basically what you said. The sheer mass of it will keep it from warping as easily. It's almost double the mass. Good luck with the swap.

[FlatlandTRD]

I think saying it's double the mass is a gross over exaggeration. Yes, you will get greater heat dissipation, and the 231 calipers will provide slightly larger hydraulic clamping power (with basically the same size pad).

But you have to look at the facts, basically everyone who has done the swap is going from warped rotors, shot pads, and black fluid to new rotors, pads, and fluid. So the change is drastic, and spectacular. And half of them even upgrade to braided stainless lines while doing the swap, so of course it's the greatest thing since aerosol cheese. Then they slap on new tires, new suspension, and stop driving like they stole it, and voila, it's a whole new vehicle.

Of course there's also those who do the swap, and note no differences. These of course are the outcasts who probably also claimed the deck plate mod didn't give them 20hp and 5 more mpg (bunch of pessimists). Don't get me started on the tundra coils!

Point is, you will notice a difference. Has any R&D gone into this swap? Nothing scientific. Will I also do it, probably at some point, but I would only go to the 231s. I did notice a slight increase in stopping power just from braided lines, but I also flushed the system and put in new fluid. So it was hardly worth starting a new thread about my new-found magnificent stopping power.

Good luck with the install, hope it all goes smoothly, and make sure to let us know what you think. I honestly hope it's as glorious as some claim, because then I can justify the expense

[Jetboy]

Thanks for the responses.

Flatlander; I think you're probably correct in that there isn't quite as much difference between new 3rd gen to new tundra, but a big difference between 170k mile worn out 3rd gen and new tundra. Unfortunately I don't have a decent way to measure the weight of each disk. Otherwise I'd do a better comparison.

My braking force is just fine. I actually have zero problem with brake performance. I can stop my sailboat anytime without trailer brakes (although it's not that heavy). I have towed my fj40 on a flatbed and stopping was acceptable without the trailer brakes (of course I had trailer brakes, I just tried it around town without them to see what it would be like). Ultimately the current brakes have enough friction to lock up the tires any time. And they are considerably larger than what I have on the fj40 which stops 38's with no problem at all. Same with the 80 series. Heavier vehicle, smaller brake disks, no stopping or warping problems.

Unfortunately I also have warped rotors that need replacement. So the Tundra swap seemed like the better option. I hope that everything claimed about better performance is accurate. The only part I really care about is the warping and I don't see any reason a 231mm pad would generate less total heat. I guess it might dissipate heat faster though.

I'll post up some good pics with all the critical measurements.

[LukeZero]

If I might talk you out of it...

Get some new rotors (high quality)- switch to the upgraded Toyota pads for the 3rd generation 4Runner. You'll be exceptionally happy, without spending much time, money or effort.

I switched to the better pads (from CDan) about 22,000 miles ago- mucho, mucho mejor (better). The only thing I can figure is that the composition of the upgraded pads dissipates heat better off the rotor. The difference is like night and day. With the stock pads and new rotors, I was warping them within 500 miles.

Good luck,

Luke
http://forum.ih8mud.com/95-gen-toyot...ds-rotors.html

Toyota part number appears to be 04465-35240

[Jetboy]

Originally Posted by LukeZero

If I might talk you out of it...

Get some new rotors (high quality)- switch to the upgraded Toyota pads for the 3rd generation 4Runner. You'll be exceptionally happy, without spending much time, money or effort.

I switched to the better pads (from CDan) about 22,000 miles ago- mucho, mucho mejor (better). The only thing I can figure is that the composition of the upgraded pads dissipates heat better off the rotor. The difference is like night and day. With the stock pads and new rotors, I was warping them within 500 miles.

Good luck,

Luke
http://forum.ih8mud.com/95-gen-toyot...ds-rotors.html

Toyota part number appears to be 04465-35240

I've already got the tundra stuff. And I'm only into it $150 for the tundra calipers and rotors from a low mile junkyard Tundra. That's probably what I'd spend on a good quality pair of rotors. I've been shooting some pics and taking detailed measurements to make a better comparison.

What's clear is that the rotors are nearly identical in surface area, but the Tundra rotors are probably 50-70% thicker in the wear surface. However I think the real difference is in the pads. I'm guessing that the upgraded pads are just tundra pads. The calipers are identical except for the width. The pads are interchangeable. However the Tundra pads cover almost the entire surface area available for friction. The 4runner pads have much less surface area. Additionally the 4runner pads have a sort of V shape where they have more contact area at the outer edge than in the center. My guess is that based on the shape of the 4runner pads, they heat up a narrow outer band of the rotor and cause warpage.

In the end I'll end up with Tundra brakes because I already have them. I'll do the swap today. Ultimately I think you're right. The swap, while certainly upgrading rotors to thicker heavier material, is unnecessary. The pads are where the real difference is. In fact I think you could just turn the rotors and throw tundra pads in an it would give a similar effect.

[theferg]

Originally Posted by Jetboy

In the end I'll end up with Tundra brakes because I already have them. I'll do the swap today. Ultimately I think you're right. The swap, while certainly upgrading rotors to thicker heavier material, is unnecessary. The pads are where the real difference is. In fact I think you could just turn the rotors and throw tundra pads in an it would give a similar effect.

Hmm. This has got me thinking. I've been loading more and more weight on my 4Runner and I have started to think a lot about how all the extra weight is affecting my brakes (among other things...). This thinking has brought me searching over and over about the "Tundra brake upgrade" and I have just about been sold on it--mostly because of all my extra weight. This new info you've posted has got me thinking a bit more now as well. I may just try some nice new rotors and some nice new OEM tundra pads and see how she feels.

Now I've not got any warpage or anything, but I can def feel all the extra weight fighting against the brakes and I could def use some more efficient braking. I'll keep ya posted when I get to this, but I prob won't worry about it until after the Holidays.

-Ferg-

[Jetboy]

I'll try to post up more info and pics later tonight when I get home, but the overall impression is good. The stopping power is very similar to what I had with the OEM brakes. I can't say there's a noticeable difference except bviously the warpage is gone. And it should be the same. The piston size is exactly the same in the tundra caliper as the 4runner. So the clamping force is identical between the two brake sets.

One thing I noticed when installing that I hadn't noticed before is that the actual wear surface of the Tundra rotor is wider. That is why you need to grind a bit off the dust shield. Not for the 199mm caliper, but for the rotor. (for the larger caliper some is needed for both) It has approximately 7 mm more material on the wear surface on the inside. I'm not sure how much effect that has. What it does mean is that tundra pads will NOT work on 4runner rotors. On the outside they'd be fine. On the inside they would hang slightly over the inside lip of the rotor. (They fit just fine in the calipers.)

Each wear surface disk (I'm not sure what to call it, but I'm referring to the thin disk that's ~4" that the pad contacts and not the full disk. so each rotor has 2 separated by slots) on the tundra is ~3mm thicker or ~30%. Also the tundra rotor has more slots. The spacing on the cross braces in the slots is about twice as far on the 4runner calipers. Also keep in mind that this may not be a perfect comparison. This is new OEM tundra rotors compared to aftermarket 4runner rotors that were installed by the PO. Not sure what brand or level of quality. Some aftermarket rotors are thinner lighter castings than OEM.

Also the stock 6 spoke 16" wheels fit just fine without any grinding. I've read on some guides that you had to take a bit off the wheels. Mine fit with ~ 2mm of clearance. No rub, no problem. I also have a set of FJ cruiser wheels and they fit with lots of space. Probably over an inch.

So those are my impressions. If I had it to do over I'd probably just buy a good quality, maybe OEM, rotor and the upgraded pads. I see no reason why good stock rotor shouldn't be up to the task. I took a sharpie and outlined the 4runner pad on the old rotor and then outlined the tundra pad next to it. That's where the difference is IMO. The 4runner builds up a lot of heat in a narrow ~1.5" band where the tundra pads spread the friction more evenly over the rotor surface.

In the end I'm only into the brakes for ~ $300 and $100 was due to having to buy a rebuilt caliper on Sunday because I needed to get it back together and the salvage yard one had a bad piston.

[simpletallman]

From your description, you have the 199mm Tundra brakes. I have those too. I haven't noticed much improvement for regular duty braking, but when they get hot, like when I'm pulling my trailer, the difference is obvious... as has been said, due to the thicker rotor and extra pad surface. There are however bigger Tundra brakes (231mm), that have much bigger calipers and pads, while using the same rotors. These supposedly work even better, but are more expensive, and require the removal of some of the material of stock rims for clearance.

[Jetboy]

I do have the 199mm calipers. I figured they'd be good enough although they are actually more or less identical to the 4runner in every dimension except center gap width.

If anyone has the 231mm calipers, I'd be interested to see what the piston diameter is. My guess is that they also share the same piston diameter (and therefore same clamping force) and the braking difference is in pad contact area.

Here's a couple pics

Tundra rotor left, 4runner right
4runner caliper left, Tundra right,
outline of tundra v. 4runner pad (note that the tunrda pad would actually hang about 3mm off the inside of the rotor). This is where I believe the key difference is. If you look at the shape of the 4runner pad it heats up a relatively narrow ring of the disk. I think that's the root of the heat/warp problem.

[Jetboy]

One more: This is where the grinding needs to be done. Note that the clearance is for the tundra rotor having more material on the inside, or a smaller inner radius.

[theferg]

Thanks for the pics jetboy.

So the idea of tundra pads with 4runner calipers and rotors is obviously out, but perhaps tundra rotors and pads, and the 4runner calipers? Thoughts?

-Ferg-

[FlatlandTRD]

Originally Posted by Jetboy

I do have the 199mm calipers. I figured they'd be good enough although they are actually more or less identical to the 4runner in every dimension except center gap width.

If anyone has the 231mm calipers, I'd be interested to see what the piston diameter is. My guess is that they also share the same piston diameter (and therefore same clamping force) and the braking difference is in pad contact area.

This is interesting, as everyone else who has done the swap, and took the time to measure, resulted in a slightly larger piston with the tundra calipers. Since this mod in '05, I believe you're the first to say different. Guess that shows how great the info has been

Apparently, the one thing they did better on the tacomas were the calipers, as our are around 219mm. I'm over 140K with no warping our shutter under hard braking (I should probably think about getting new though). But the thicker rotor should make things better with the improved heat dissipation.

Also, with larger calipers is there an increase in fluid capacity, although minimal, does that effect fluid dynamics? Glad it went smoothly.

[Jetboy]

Originally Posted by theferg

Thanks for the pics jetboy.

So the idea of tundra pads with 4runner calipers and rotors is obviously out, but perhaps tundra rotors and pads, and the 4runner calipers? Thoughts?

-Ferg-

Won't work with the 4runner Calipers. The center gap isn't wide enough to fit with new pads. Might work with slightly used pads, but I doubt many would be into it.

[theferg]

Originally Posted by Jetboy

Won't work with the 4runner Calipers. The center gap isn't wide enough to fit with new pads. Might work with slightly used pads, but I doubt many would be into it.

Ah yes. Forgot for a moment about the tundra rotor being thicker.

-Ferg-

[Jetboy]

Originally Posted by FlatlandTRD

This is interesting, as everyone else who has done the swap, and took the time to measure, resulted in a slightly larger piston with the tundra calipers. Since this mod in '05, I believe you're the first to say different. Guess that shows how great the info has been

Apparently, the one thing they did better on the tacomas were the calipers, as our are around 219mm. I'm over 140K with no warping our shutter under hard braking (I should probably think about getting new though). But the thicker rotor should make things better with the improved heat dissipation.

Also, with larger calipers is there an increase in fluid capacity, although minimal, does that effect fluid dynamics? Glad it went smoothly.

I guess I could be wrong. I didn't pull the pistons out, but I measured the rim. I assumed if they are were the same the piston diameter is also the same. I was just using a cheap vernier caliper. Could be a bit difference, but I'm reasonably confident it's less than a mm difference. I'm also pretty sure that the pistons are interchangeable. FWIW I also measured every other dimension I thought of. All the casting widths and bolt spacings are also the same.

[Jetboy]

Originally Posted by theferg

Ah yes. Forgot for a moment about the tundra rotor being thicker.

-Ferg-

The way they are built (two piece, bolt together), you could just machine two spacers for each caliper and be in business. Of course you can get junk yard tundra calipers for $35/ea so it's just cheaper to use Tundra parts.

[Bighead]

I'll be curious to see how you like the brake upgrade. It has been interesting reading everybody's impressions of this change. Personally I have not done it since I have never had a problem with the stock set-up...my only brake upgrade has been extended rear, braided stainless lines.

Good luck with the swap.

Originally Posted by FlatlandTRD

Don't get me started on the tundra coils!

Hey....I like my Tundra coils.

[Jetboy]

Originally Posted by Bighead

I'll be curious to see how you like the brake upgrade. It has been interesting reading everybody's impressions of this change. Personally I have not done it since I have never had a problem with the stock set-up...my only brake upgrade has been extended rear, braided stainless lines.

Good luck with the swap.



Hey....I like my Tundra coils.

Overall the feel is just like stock. If someone snuck into my garage and swapped them during the night, I wouldn't notice. Except they don't warp when they heat up. Nice smooth linear stops, not shimmy at all. It's gotten chilly here, so I'm not sure I'll end up towing the boat till next spring. I'm pretty sure that was what did me in as far as warping goes.

I also suspect that rear brakes being out of adjustment may have added to the overuse of the fronts. I've been using the back up/ pull the e-brake adjustment to try to make sure they are doing their share of the braking. They might be due for a rebuild soon too. I've had them in salt water a couple times putting the boat in and I can only imagine that there might be some rust inside.

[austintaco]

My experience. I swapped the 199mm calipers on my 03 double cab Tacoma. I didn't really notice a difference, but I would expect to notice a difference when towing. I did flat tow a 1st gen 4runner and the brakes never faded and felt like stock, but I have nothing to compare it to.
I actually found a guy on craigslist who had his old calipers and rotors from the recall and I bought everything for around $50, so my investment was small.

[cackalak han]

Originally Posted by FlatlandTRD

I think saying it's double the mass is a gross over exaggeration. Yes, you will get greater heat dissipation, and the 231 calipers will provide slightly larger hydraulic clamping power (with basically the same size pad).

But you have to look at the facts, basically everyone who has done the swap is going from warped rotors, shot pads, and black fluid to new rotors, pads, and fluid. So the change is drastic, and spectacular. And half of them even upgrade to braided stainless lines while doing the swap, so of course it's the greatest thing since aerosol cheese. Then they slap on new tires, new suspension, and stop driving like they stole it, and voila, it's a whole new vehicle.

Of course there's also those who do the swap, and note no differences. These of course are the outcasts who probably also claimed the deck plate mod didn't give them 20hp and 5 more mpg (bunch of pessimists). Don't get me started on the tundra coils!

Point is, you will notice a difference. Has any R&D gone into this swap? Nothing scientific. Will I also do it, probably at some point, but I would only go to the 231s. I did notice a slight increase in stopping power just from braided lines, but I also flushed the system and put in new fluid. So it was hardly worth starting a new thread about my new-found magnificent stopping power.

Good luck with the install, hope it all goes smoothly, and make sure to let us know what you think. I honestly hope it's as glorious as some claim, because then I can justify the expense

I'll agree with you there. Just like people who get drilled/slotted rotors and think they stop so much better, but in reality, it's just the new pads/rotors vs old.

But I do believe the benefits are there for the Tundra upgrade. R&D? I don't think anybody went through any thermal testing or 60-0, 100-0 tests, but from people that tow quite a bit, they have noticed no or less warpage, whereas they went through the s12/s13 rotors like crazy. That's got to account for something.

Also, if it's no big deal adding 50-75% more mass with slightly larger pads, why did Toyota even do a TSB from 199 to 231's? I'm sure they put their time and efforts in testing out various systems and concluded the 199/231's were the best for heavy hailing and towing. Like I said, if I start to tow more, I'm doing this upgrade.

[Jetboy]

Just wanted to add a note that the antirattle clips from the 4runner will fit on the tundra set and work just fine. None of the auto parts stores around here had them. Dealer only I guess. They had a different style of little thin wire springs, but no need to buy them. You do of course need longer caliper pins.

[Aznwolf118]

I agree with flatland trd.
i did the trundra brakes while i installed my ss1.2 kit. just made sense to me while everything was off.
i ended up with the 231mm calipers and got SS brake lines to go with them.
biggest imporvement i felt was from the brakelines, the pedal felt better. i have yet to tow of wheel and see how the brake perform.