TBU 231mm vs. 199mm Pad Size

X

xcmtb83

Member
Well even though there are countless threads on the Tundra Brake Upgrade I wasn't able to find an answer to my questions. My apologies for yet another TBU post!

Pictured below on the left is a 231mm caliper (13WL) and on the right a 199mm caliper (13WE). I noticed the opening is larger on the 231 caliper which allows for a larger brake pad, or atleast a larger steel pad "backer". The actual length of both pads is about 4.7 inches but notice the gap between the pad of the 231 and the actual caliper. This seems like wasted area that a pad could occupy.

Why wouldn't the pad on the 231 extend as close to the caliper as the pad does on the 199?

Do all 231 pads have this gap?

Was Toyota strictly wanting more thermal mass by going with the later model 231mm caliper versus the 199mm caliper or did they also increase the surface area of the pads and I just happen to have a weird aftermarket pad in the 231mm caliper?

Also, the rotors for 231mm calipers and 199mm calipers are identical, correct?

TIA!
 

Attachments

  • 231 vs. 199 2.jpg
    231 vs. 199 2.jpg
    140.8 KB · Views: 2,026
Register to hide this ad
The gap is there by design. It helps allow a path for gas/heat/brake dust to escape without having to go through the entire length of the pad to escape.
 
Bad Luck said:
The gap is there by design. It helps allow a path for gas/heat/brake dust to escape without having to go through the entire length of the pad to escape.
Click to expand...

The gap I was referring to was the gap between the pad material and the metal caliper. Not the slot in the pad material. :)
 
xcmtb83 said:
The gap I was referring to was the gap between the pad material and the metal caliper. Not the slot in the pad material. :)
Click to expand...
I see. Yes, all the 231 caliper pictures I've seen have that gap including the OEM calipers I rebuilt and installed on my 4Runner with OEM pads.
 
The larger/stout 231mm calipers have a greater breaking force... don't be misled by visuals in this case. Similar size (in length) pads though a step up in performance. Judging by the post date, you've probably made your decision by now and are enjoying the drastic change in breaking performance. Either one, 199mm or the 231mm, will be a night and day difference from stock. Anyone considering this upgrade will benefit from both, its merely a choice of what fits inside your wheels.

Sent from my SM-G955U using Tapatalk
 
I’ve put 2005 tundra 4x4 rotors, calipers, and pads on 3 different rigs. Night and day difference. Better stopping, they don’t warp in 6 months, much less fade, oh and better stopping.

I just tell the parts counter I want rotors, calipers, and pads for a 2005 tundra 4x4.
 
Last edited:
Dieselchessy said:
This is wrong. Tundra 231 rotors are noticeably thicker, real noticeable.

I’ve put 2005 tundra 4x4 rotors, calipers, and pads on 3 different rigs. Night and day difference. Better stopping, they don’t warp in 6 months, much less fade, oh and better stopping.

I just tell the parts counter I want rotors, calipers, and pads for a 2005 tundra 4x4.
Click to expand...

I think he means that the rotors you need for either the 231 or 199 upgrade are the same. The stock 4Runner rotors are smaller.
 
JZiggy said:
I think he means that the rotors you need for either the 231 or 199 upgrade are the same. The stock 4Runner rotors are smaller.
Click to expand...

Having re-read the statement you are correct.

Having now gone through the mental game of “why would someone half step to first gen tundra/sequoia brakes rather than full step to second gen”.
Do folks really consider this to avoid cutting 2 little corners off the dust shield?

A rattle can of black paint and a 4 inch grinder and your there. It’s not worth the mental energy trying to consider 199mm brakes.
 
Last edited:
Dieselchessy said:
It’s not worth the mental energy trying to consider 199mm brakes.
Click to expand...



Back when I did my upgrade I ran into several threads where people who upgraded to 231 had ABS issues. It was theorized that the 96-00 master brake cylinder (or booster, i forget) was more likely to have issues dealing with the increased amount of brake fluid needed for the 231 calipers. I believe that it was said that the 01-02 had a different master cylinder or brake booster or something that didn't seem susceptible to this issue. Again, its been a while since I researched this upgrade in depth so I may be remembering incorrectly. Since mine is a 00 I decided to go with 199 to avoid this potential issue. The 199 is night and day way better than the stock brakes. I also replaced the rubber brake lines with braided SS so I'm sure that helped as well.

Here is the post when I did the upgrade.

My New 2000 Limited 4x4 E-Locker - Toyota 4Runner Forum - Largest 4Runner Forum
 
Last edited:
I did the larger TBU, (as per Timmy), and it was a huge success, great bite, immediate stops, no delays, feels like the brakes that Should've come OEM. :brushteeth:

IIRC wasn't the smaller of the two upgrades for folks with the smaller SR5 rims, (not fitting over the new, larger calipers?), mine is a Limited, so the larger wheels prevail.
 

Attachments

  • tbu.jpg
    tbu.jpg
    49.4 KB · Views: 1,606
Last edited:
Novashards said:
Back when I did my upgrade I ran into several threads where people who upgraded to 231 had ABS issues. It was theorized that the 96-00 master brake cylinder (or booster, i forget) was more likely to have issues dealing with the increased amount of brake fluid needed for the 231 calipers. I believe that it was said that the 01-02 had a different master cylinder or brake booster or something that didn't seem susceptible to this issue. Again, its been a while since I researched this upgrade in depth so I may be remembering incorrectly. Since mine is a 00 I decided to go with 199 to avoid this potential issue. The 199 is night and day way better than the stock brakes. I also replaced the rubber brake lines with braided SS so I'm sure that helped as well.

Here is the post when I did the upgrade.

My New 2000 Limited 4x4 E-Locker - Toyota 4Runner Forum - Largest 4Runner Forum
Click to expand...

Just for another data point for you.

I've done 3 of these on personal rigs and been involved in 3 more on friends rigs. My 3 include 2, 98 manuals and a 99 auto. The other 3 are pre-99 (no fat lip) and a 2000 or 2001 auto.

In all cases no issues with ABS. I currently drive a 98 with no issues for the last 6 months or so, and own a 99 that's had no issues with the swap in maybe 5 years or more.

I live in the hills and drive in ice and snow a few weeks every winter. I've chattered the ABS plenty of times, sometimes for 50 foot stretches. In my estimation it works as it always has.
 
Somewhere in the inter webs there is a thread where folks commented on what rims fit and what don't.
I don't know all the lingo for the rim names. Of the rigs that I've dealt with all the 16 rims have fit.
 
I did the 199mm (13WE) swap because I found information threads on this website that the 231's would not fit with the specific existing stock wheels. It wasn't a reluctance to cut the dust shield.

Was having to replace existing stock rotors anyway so when I found a pair of 13WE calipers on ebay for $50 (plus $20 for the seal kits) I figured it was a nominal price for a good upgrade. They work great and the the brakes are noticeably better.
 
Varangian said:
The larger/stout 231mm calipers have a greater breaking force... don't be misled by visuals in this case. Similar size (in length) pads though a step up in performance. Judging by the post date, you've probably made your decision by now and are enjoying the drastic change in breaking performance. Either one, 199mm or the 231mm, will be a night and day difference from stock. Anyone considering this upgrade will benefit from both, its merely a choice of what fits inside your wheels.

Sent from my SM-G955U using Tapatalk
Click to expand...

FYI - The piston sizes of 231 and 199 are identical, I measured them myself. My point is, the braking forces are the same for 231 and 199. The major difference is the amount of thermal mass when comparing 199 to 231.
 
xcmtb83 said:
FYI - The piston sizes of 231 and 199 are identical, I measured them myself. My point is, the braking forces are the same for 231 and 199. The major difference is the amount of thermal mass when comparing 199 to 231.
Click to expand...
Do you remember what the pistons measure out to?
 
You must log in or register to reply here.

Members online

No members online now.
Total: 211 (members: 0, guests: 211)

Forum statistics

Threads
278,306
Messages
3,554,045
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top