231mm / 199mm Tundra Brake Upgrade ABS Function Survey

[gamefreakgc]

Was gonna make the switch soon after my lift, and after seeing the poll I'm curious as to why someone would choose the 231mm over the 199mm? Especially considering it needs a little fitment

More pad surface area = more stopping power. If you've got extra weight with armor, bumpers, gear, or if you are towing, that extra braking power is very good to have. A lot of us already have wheels that clear, it's only the split-spoke wheel users that have issues.

For me, it was a combination of occasional towing at the time as well as faster speeds. I darn sure needed to know I could stop fast before I could go fast.

For the poll question, for me it was the opposite. On stock brakes and so-so tires, my brakes would not engage when I needed them most. On several occasions I skidded out into intersections with moderate braking in the rain (I know how to brake, this is my first vehicle with ABS). I felt safer WITHOUT the ABS system. After switching brake size, the ABS behaves much better. Still comes on if I hit a speedbump too fast though...

 

[NachoRunner]

Late to the party here but thought I would offer my insight with a useful post to up my post count so I can create a new post...I have a 2002 and a 1997 both with the 231 setup.

The '02 I've had the longest with over 100k miles on the Tundra brakes and zero issues. Awesome upgrade. Currently about 330k on this rig. Pretty much all stock except this brake upgrade.

The '97 is a little bit of a different story. Only about 35k miles with the Tundra brakes. I immediately had issues with the ABS. I dis-abled ABS by removing the fuse and it has been great since. I don't really like the ABS light on or dis-abling such vital equipment but I found it necessary. I leave the light on so anyone that should drive it would know it's dis-abled. This is a relatively low mileage rig with about 170k currently also all stock except the brake upgrade.

My theory, and perhaps it's covered other places, is the larger brake booster on the 2002 deals with the bigger brakes better. There was no conclusion to this survey but that is my conclusion based on this experience over 9+ years with these rigs. Maybe the 199 would be a good compromise for some with the pre2002 but I think bigger is better here. Particularly since I am in the Colorado mountains and heat fade is real.

Quickly reading the previous posts it seems some people with the bigger booster also had issues so maybe this is not a definitive conclusion but like I said, this has been my experience. HTH someone!

 

[T4R2014]

Two 4Runners. 1996 and 1998 with the 199mm upgrade. The 1996 is going on to nine years with the upgrade and the 1998 is going on to 8 years. This upgrade did not necessarily correlate to reduction in brake rotor warpage, and I cannot speak with data on whether my braking distance was reduced. The 1996 warped a set of WBR rotors and a set of Brembo rotors within 2 years, both had Axxis Semi Metallic pads. The 1998 warped a set of Powerstop Rotors in less than two years with same brand ceramic pads. Warpage stopped when I switched to EBC rotors with Greenstuff pads in the 1998, and EBC rotors with whatever lower grade pad they sell, both 4Runners were able to achieve full brake pad service life without warpage. I can't really find a cost effective source for resurfacing rotors, so I cannot speak on how much more life the EBC rotors had to offer. So I'm concluding for now that quality and spec of parts is of way more importance than the upgraded calipers in reducing warpage.

Also, neither truck had ABS issues that could be attributed to the upgraded calipers, and I can't see how that would be. I notice the information on 3rd gen 4Runner ABS system diagnostics is slim to say the least. Maybe [MENTION=120071]mtbtim[/MENTION] could solve that issue. I recommend you pull codes using whatever method applies to your model year (I can tell you the method for a 1996 is different from a 1998). From that you determine where to look. Most of my ABS issues have been related to bad rear ABS sensors or damage to the wiring harness that routes through the fuel pump wiring access hole and across the tubular crossmember. You would need to inspect wiring, and then isolate the issue to the sensor or pump by analyzing waveforms via oscilloscope. Picoscope is definitely more cost effective for this, I don't think you need a $1k+ Fluke to do this. Saying the TBU caused ABS issues is just guessing.

 

[WayneM]

I have a 2001 Limited that I've had for 21 years. I have done both 13WE/199 and 13WL/231 TBU on this same vehicle.

In all those years, I've only had 1 incident where I expected ABS to do something, and it did -nothing-. That was a glazed snow, ski area, parking lot on a minor incline. I had HT road tires. As I tried to turn/park, I faced the choice of a turning into a snow bank (front wheels rolling) or sliding into another car (front wheels locked). I slowly drove into the snow bank.

Admittedly, it was a very slow speed situation on a very slippery surface. This was when I had 13WE/199 TBU. I'll add this to the survey, but it may be an unfair statistic.

I now have the 13WL/231 TBU. Next time I'm on gravel, I'll try a few tests.