GMT T1XX brake upgrade

[mars2878]

Went on GMC's website to do some research. Went to the build a brand new vehicle link. It gave options for 2025 & 2026 Yukon At4 Ultimate. Tried with both the Turbo Diesel & 6.2L engines. The R4L Rim, which is what have, is the standard Rim. No optional rims were offered. Left everything as standard equipment, except for when I got to the Brembo 6-piston upgrade. That I selected. So in total, I did this 4 times with all of the standard equipment & the only options being the engine & adding the brake upgrade.
All 4 times it let me get to the last screen showing the grand total price. Then it shows if any of that model are available. It showed like 6 available for, but none with the brake upgrade.


As you can see in the next picture, it is showing the 6-piston brakes with R4L rims.

 

[mars2878]

This is the screen after selecting the more info tab. It doesn't specify as to which specific requirements are required.

So I'm still at a lose as to why GM says that the Vin# that I have is no-go for the factory brake upgrade?

 

[AuroraGirl]

Lots of interesting info.

Never knew about the ABS module having tire specs in them. When selling them, we always matched the part number on them. Our system only gave a year, model, engine interchange on those.
Didn't know about reprogramming them either.

We usually just gutted the ABS system when it was faulty.

the numbers and features listed on them are important because of hardware differences. a ABS module with more features even without external differences might have additional board components

 

[AuroraGirl]

This is the screen after selecting the more info tab. It doesn't specify as to which specific requirements are required.
View attachment 5955
So I'm still at a lose as to why GM says that the Vin# that I have is no-go for the factory brake upgrade?

what about a vin being told is a no go?

 

[mars2878]

the numbers and features listed on them are important because of hardware differences. a ABS module with more features even without external differences might have additional board components

I understand what you are saying.

You're just the 1st person that I ever notice saying anything inregards to the ABS module when upsizing wheels.
Even when I worked in shops that installed aftermarket rims.
We did always tell people that the speedometer might be off, so they needed to it calibrated to make sure that they didn't get a ticket.
Even the current threads on other sites when people are talking about upsizing the wheels on a gmt800 or gmt900, no one mentions the ABS. It's always about backspacing, spacers, clearing the brakes, fitting within the wheelwell. Some of that info varies depending upon if stock height, lowered, or lifted.

I wonder what year that became a thing with ABS modules?

 

[mars2878]

what about a vin being told is a no go?

I have a Vin # for a 2025 Yukon at4 Ultimate 6.2L with the R4L rims & 4-piston calipers as I currently can not find a Vin for one the 6-piston setup. On GM's site, I select the 6-piston upgrade part package. It then asks for the Vin #, so I enter it. It then says that it's not compatible.

The whole point of this thread was to figure out what options are needed on a 2025 Yukon at4 Ultimate with R4L rims to compatible with the 6-piston brake upgrade.

If I go to the GMC site, I can build out both a 2025 & a 2026 Yukon at4 Ultimate with R4L rims with either the Turbo Diesel or the 6.2L it let's me option it with the 6-piston upgrade. Everything else is standard equipment including the no-charge White paint. It then tells me that none are currently for sale & wants me to proceed to order to have it built.

 

[AuroraGirl]

I have a Vin # for a 2025 Yukon at4 Ultimate 6.2L with the R4L rims & 4-piston calipers as I currently can not find a Vin for one the 6-piston setup. On GM's site, I select the 6-piston upgrade part package. It then asks for the Vin #, so I enter it. It then says that it's not compatible.

The whole point of this thread was to figure out what options are needed on a 2025 Yukon at4 Ultimate with R4L rims to compatible with the 6-piston brake upgrade.

If I go to the GMC site, I can build out both a 2025 & a 2026 Yukon at4 Ultimate with R4L rims with either the Turbo Diesel or the 6.2L it let's me option it with the 6-piston upgrade. Everything else is standard equipment including the no-charge White paint. It then tells me that none are currently for sale & wants me to proceed to order to have it built.

it may just be about it not being on dealer lots then tbh

 

[AuroraGirl]

I understand what you are saying.

You're just the 1st person that I ever notice saying anything inregards to the ABS module when upsizing wheels.
Even when I worked in shops that installed aftermarket rims.
We did always tell people that the speedometer might be off, so they needed to it calibrated to make sure that they didn't get a ticket.
Even the current threads on other sites when people are talking about upsizing the wheels on a gmt800 or gmt900, no one mentions the ABS. It's always about backspacing, spacers, clearing the brakes, fitting within the wheelwell. Some of that info varies depending upon if stock height, lowered, or lifted.

I wonder what year that became a thing with ABS modules?

1988 when they introduced the EBC4 4WAL abs on the C/K trucks (i think the suburban/blazer may have had some on the R/V line somewhere 1988-1991), would have only used a calibration for tire size for wheel speed sensor calibration so it knows the proper speed of the tires only.

The EBC310 in the 199(4?) to end of Gmt400 would have used the info the same way.

The EBC325 and EBC325v in the Gmt800 trucks use the calibration a little bit more. 1) since there is DRP(Dynamic rear proportioning) It uses this info to help know modulating the rear brake pressure what the road contact patch, tire diameter, etc look like so it can assign the right value since this is going to use static math for crude curves/scenarios, its not the biggest change in the world but its still gonna be considered.

The biggest thing is for calibrating the speed of the wheel as it rotates, since there were many tire size options it wants to know what one so it uses th right tables.