'15+ brake upgrade? OR upgrade to 2500 brakes

[kbuskill]

I have seen where guys upgrade the GMT800 trucks to the GMT900 front brakes.

My question is twofold.

1. Are the '15+ brakes any bigger/better than ours and will they bolt up, perhaps with a bracket to move the caliper out???

2. I was reading the GMT800 brake upgrade thread and read that the GMT800s run better rear calipers. If this is the case will the rear calipers bolt onto a GMT900 without much trouble???

I was looking at the '15+ section and read where someone said the brakes are 14" diameter but looking up the rotors for a '15 Tahoe I found conflicting info. Some said 13.5" some said 12.99".

I am very content with the cross drilled and slotted rotors and ceramic pads I am currently running but I am always interested in upgrading where I can. I just hadn't seen any discussion about this being plausible so I thought I would get the conversation started.

Any info is appreciated.

 

[kbuskill]

Really?.... Nobody?....

I figured I could at least count on someone to call me names if nothing else.


******* EDIT *******

I added to the title since we started talking 2500 components.

 

[Ilikemtb999]

Really?.... Nobody?....

I figured I could at least count on someone to call me names if nothing else.

So what I gather from looking at part numbers, from my 2010 to a 2016 Tahoe they use the same caliper and caliper bracket. Same with front rotors.

 

[kbuskill]

So what I gather from looking at part numbers, from my 2010 to a 2016 Tahoe they use the same caliper and caliper bracket. Same with front rotors.

Any thoughts on running the GMT800 rear calipers on the GMT900?

 

[Ilikemtb999]

Any thoughts on running the GMT800 rear calipers on the GMT900?

You do get a dual piston caliper it seems with a gmt800 but the 900 has a .5” larger diameter rotor so you’d need an adapter bracket. Unsure you really want that much more pad in the rear if you’re not upping the front. Here are the pad differences too, I’m guessing all things considered it probably evens out (larger diameter vs more pad surface area)
Gmt800

Gmt900

 

[Ilikemtb999]

I think the coolest upgrade would be to 2015+ 2500hd brakes front and rear. Large calipers and larger rotors (and much thicker). The ones on my gmt900 2500hd were awesome (same diameter as my Tahoe but much thicker with bigger calipers). The rear calipers were actually the same as the front calipers on my gmt800 truck. One day I’ll mock up some brackets to put a set on my k5 blazer as the Dana 60 front calipers are pure trash.

 

[intheburbs]

I would go with this^^^^^

I've always felt the half-ton GM trucks are underbraked. Both my '01 Burb and '09 Denali have had chronic rotor warping problems, and seemed to need new pads more frequently than usual.

Contrast that to my 2500 Burb. I bought it with 100k miles, it now has 185k miles and hasn't even needed a brake job yet. That includes at least 20,000 miles of towing really heavy stuff. Also includes my stint in Ann Arbor as an Uber driver - lots of short trips and tons of starts/stops. When I rotated the tires back in October there was still plenty of meat on the pads. Never have had a warped rotor, and when you hit the brakes even at extralegal speeds, she stops smooth and sure.

If you're going to go through the effort/expense, I would definitely upgrade to bigger and better.

 

[Ilikemtb999]

I would go with this^^^^^

I've always felt the half-ton GM trucks are underbraked. Both my '01 Burb and '09 Denali have had chronic rotor warping problems, and seemed to need new pads more frequently than usual.

Contrast that to my 2500 Burb. I bought it with 100k miles, it now has 185k miles and hasn't even needed a brake job yet. That includes at least 20,000 miles of towing really heavy stuff. Also includes my stint in Ann Arbor as an Uber driver - lots of short trips and tons of starts/stops. When I rotated the tires back in October there was still plenty of meat on the pads. Never have had a warped rotor, and when you hit the brakes even at extralegal speeds, she stops smooth and sure.

If you're going to go through the effort/expense, I would definitely upgrade to bigger and better.

My 2500hd had its first brake change at 120k. Was still wearing factory rotors and pads (pads were cracking and almost to the wear bars). Replaced with new centric stuff and ac delco pads and good as new. Huge difference in just size and stopping power compared to 1/2 ton stuff. The 15+ looked like it’s got almost 14” rotors with similar looking calipers so can’t imagine how much better it stops too.

 

[kbuskill]

You do get a dual piston caliper it seems with a gmt800 but the 900 has a .5” larger diameter rotor so you’d need an adapter bracket. Unsure you really want that much more pad in the rear if you’re not upping the front. Here are the pad differences too, I’m guessing all things considered it probably evens out (larger diameter vs more pad surface area)
Gmt800
View attachment 213882


Gmt900
View attachment 213883

Thanks for the info...

This is why I asked.

On my, 1st gen, 2000 Escalade (basically a '98 Tahoe) I upgraded ALL the brakes.

I used the master cylinder from an '03-'06 Tahoe (If I remember correctly) along with 1 Ton rear wheel cylinders (bigger diameter) and I believe it was the (bigger) PPV front calipers. It has been so long ago that I forget all the details.

Anyway, prior to the upgrade the pedal always felt kinda soft even with brand new stock parts.

Afterwards the pedal was nice and firm and it felt like less effort was needed to stop.

The only issue I had with brakes on that truck was the drum brakes just would not stay adjusted. I would have to back up to self adjust the brakes every couple days.

I changed all the hardware inside several times to no avail. The worst part is it was my wife's daily and she wouldn't do the backing procedure to adjust them because it made her sick... I used to do it with her in the truck just so I could pick at her, she will ride roller coasters all day long but put her in a vehicle and back up quickly and hit your brakes a few times, or do some donuts on a dirt road, and she's ready to vomit.

Any way, when she would let the rear brakes get out of adjustment and keep driving it like that it would end up shearing the brake shoe retainer pins off. If we had kept the truck, I was seriously considering swapping over to disks on the rear.

I had read that the drums not staying adjusted was a fairly common issue on those but not entirely sure.

Any way back on topic.

I haven't really researched any of the possibilities for upgrading the GMT900 so I thought I would ask in case I just missed it.

Thanks for the help so far.

 

[Ilikemtb999]

You could always do hydroboost. That’ll get a firm pedal and lots of stopping pressure going.

 

[kbuskill]

You could always do hydroboost. That’ll get a firm pedal and lots of stopping pressure going.

I am pretty happy with the current setup I am running on the '08 Burb. I am always looking for ways to upgrade though.

I currently have cross drilled and slotted rotors, front and rear, with ceramic pads. I also just flushed all the old fluid out and replaced with new DOT4 synthetic brake fluid. Nice firm pedal and she stops very well.

At some point I may install SS braided lines all around.

 

[kbuskill]

So I have been doing some more poking around on rock auto and found out some interesting info.

The 2011 Suburban 2500s calipers have slightly bigger pistons.

2.3" on the 2500 VS the 2" on the 1500. That's a net gain of .6" in diameter combined. The pads are bigger also, so more surface area.

Here are the specs I copied down for the front of both 1500 and 2500 trucks for comparison.

2011 Sub 2500
Front Caliper ACDELCO 18FR1380
Dual 2.3" piston
Rotor 12.8 diameter
Thick 1.5
Height 3.51
Center bore 4.65
Pads 216.2L x 67H x 18.2T

2011 Sub 1500
Front Caliper ACDELCO 18FR2659
Dual 2" piston
Rotor 12.99 diameter
Thick 1.2
Height 2.2
Center bore 3.1
Pads 184.2L x (59.4)63.9H x 18T

***********************************

And for the rear for comparison...

2011 Sub 2500
Rear caliper
ACDELCO 18FR1379
Dual 2" piston
Rotor 12.99 diameter
Thick 1.14
Height 3.64
Center bore 4.84
Pads 177L x 59.6H x 18.5T

2011 Sub 1500
Rear caliper ACDELCO 18FR2471
Single 2" piston
Rotor 13.57 diameter
Thick .79
Height 3.35
Center bore 3.1
Pads 142.7L x 45.3H x 16.9T

I believe the 2500 calipers would bolt directly onto the GMT900 1500s caliper brackets because the cross reference shows the 2500s caliper brackets fitting the GMT800 1500 and 2500 and we know the GMT900 calipers and rotors are a direct bolt on for the GMT800.

The only thing I'm not sure about is if the throat of the caliper, where the pads go, would line up with our rotors because of the difference in overall height but I imagine they would. The height difference is probably in the hat area of the rotor.

The diameter of the 1500 rotors is slightly bigger than the 2500 rotors.
1500 Front rotors are .20" bigger.
1500 Rear rotors are .58" bigger.
This would equate to an 1/8" closer to the front caliper and 1/4" approximately closer to the rear caliper because the overall diameter is split in half. I doubt that's a big enough difference to matter.

Also the thickness of the rotors are a little different but the 2500 pads are also ever so slightly thicker.

1500 Front rotor is .3" thinner
2500 front pad is .2mm thicker which is like .008"
Which is negligible.

1500 Rear rotor is .35" thinner
2500 rear pad is 1.1mm thicker which is like .04" again negligible.

The only time this should ever be a problem is if you ever let your pads get wore down to bare metal it might cause the pistons in the caliper to over extend... but how many of us let our brakes go that long???

Any way... I'm not saying it would work. I would have to compare the 1500/2500 calipers first hand before I would say for sure.

Now the 2500s with...(***with 9,900 lb Hydraulic Power Brakes, Active Brake Control (JL4)
Or 4-Wheel Disc Brakes w/Single Rear Wheels (J95), Active Brake Control (JL4)***) have a bigger bore master cylinder than the 1500s or even the 2500s with the 7,700 lb tow capacity.

2500 Master cylinder
ACDELCO 1741189
Bore Diameter 1.5 in
Primary Outlet Thread Diameter 14 MM
Secondary Outlet Thread Diameter 14 MM
***********
1500 Master
ACDELCO 18M2560
Bore Diameter 1.25 in
Primary Outlet Thread Diameter 14 MM
Secondary Outlet Thread Diameter 14 MM

Its only .25" bigger but it would definitely make a difference in the pedal feel and the amount of force applied to the calipers. I know it made a substantial difference when I upgraded my 1st gen Esky to the newer body style/bigger bore master.

Now...

Would it even be worth the effort??? Maybe, maybe not. I'm guessing it would, if it will all bolt up.

Bigger pistons equal more force applied for the same amount of effort/force. This applies to both the master and the calipers.

Bigger pads = more surface area which = more friction area.

I am 99.9% certain the master cylinder I listed above is a direct swap onto the 1500.

The rest is debatable at this point.

Maybe if I get bored later I will crunch some numbers on piston bore size comparisons of force applied.

 

[Ilikemtb999]

Does the 2500 burb have hydroboost? I think the bigger benefit is the thicker rotor which you’d have to either redrill or convert to 8 lug. The knuckles on my Sierra seemed much taller than the Tahoe so not sure how easy that is to do.


Some light reading on caliper piston sizes and brake pad sizes.

http://www.stoptech.com/technical-support/technical-white-papers/brake-system-and-upgrade-selection

 

[kbuskill]

Does the 2500 burb have hydroboost? I think the bigger benefit is the thicker rotor which you’d have to either redrill or convert to 8 lug. The knuckles on my Sierra seemed much taller than the Tahoe so not sure how easy that is to do.


Some light reading on caliper piston sizes and brake pad sizes.

http://www.stoptech.com/technical-support/technical-white-papers/brake-system-and-upgrade-selection

I am not 100% sure on the hydroboost... my guess is yes, but that shouldn't affect the master cylinder compatibility I wouldn't think.

Also I'm not considering swapping to 2500 rotors.

I was simply listing the rotor sizes for comparison.

My thought process was to use the 2500 calipers and pads on the 1500 rotors and then use the 2500 master in place of the 1500s.

 

[Ilikemtb999]

I am not 100% sure on the hydroboost... my guess is yes, but that shouldn't affect the master cylinder compatibility I wouldn't think.

Also I'm not considering swapping to 2500 rotors.

I was simply listing the rotor sizes for comparison.

My thought process was to use the 2500 calipers and pads on the 1500 rotors and then use the 2500 master in place of the 1500s.

My hydroboost experience, there’s just different depth master cylinders which require a different length rod so worst case scenario you have to make your own or swap rods. I had to do that upping my master cylinder size on my cucv when I changed to 1 tons. I’m also adding hydroboost to my Buick.

 

[fozzi58]

Not to derail your growing love of the 2500 braking system, but I threw a set of Powerstop rotors and calipers along with steel lines on my 08 Avalanche (gmt900). Powerstops are a poor man's Wilwood braking system. It was night and day before and after. And when I went from that to my 17 burban, the brakes in the 17 feel like shit even though it was brand new. Powerstop also offers a lifetime warranty on the calipers for as long as you own the truck so its a nice feature if a caliper ever freezes up on you.

Interesting to see what info you have accumulated on the 2500. Not sure I would want to go through all those changes myself but interested in seeing the outcome nonetheless.

 

[91RS]

Basically the 2005/2007 (05 on the pickups 07 on the SUVs) to 2018/2019 (18 for pickup 19 for SUV) front brakes are the same. The caliper brackets changed in 2008.5 and the OEM pads change part numbers (probably different pad friction materials) a few times. Some aftermarket pads show to fit 2005-2018. I can't see 2500 brakes being worth the trouble because there's no bolt-on solution for the rotors. You'll either need custom rotors to fit the 6 lug hubs or do an 8 lug swap to do this properly and safely. Brakes are not something to half-ass. Why not just buy the Brembo 6 piston front brake GM accessory? That'll increase your stopping power!

 

[kbuskill]

Basically the 2005/2007 (05 on the pickups 07 on the SUVs) to 2018/2019 (18 for pickup 19 for SUV) front brakes are the same. The caliper brackets changed in 2008.5 and the OEM pads change part numbers (probably different pad friction materials) a few times. Some aftermarket pads show to fit 2005-2018. I can't see 2500 brakes being worth the trouble because there's no bolt-on solution for the rotors. You'll either need custom rotors to fit the 6 lug hubs or do an 8 lug swap to do this properly and safely. Brakes are not something to half-ass. Why not just buy the Brembo 6 piston front brake GM accessory? That'll increase your stopping power!

I wasn't necessarily planning on doing this "upgrade". I was just curious and trying to start a conversation about the possibilities of what could be done using existing parts in the GM parts bin.

I already have cross drilled and slotted rotors and ceramic pads and that in itself was a noticeable improvement in braking. My next logical step would be to upgrade the rubber lines to SS.

Why not just buy the Brembo kit???

Because anybody can buy a kit. It's more fun, for me, to figure things out than to simply "buy and bolt". I am a tinkerer. I enjoy it. Its like solving a puzzle... lol

IF I were to ever persue this I would just reuse the 6 lug rotors. They are essentially the same diameter as the 2500s and only slightly thinner.

 

[intheburbs]

IMHO, the biggest weakness of the 1/2 braking system are the rotors. Not as beefy, prone to warping. If I was doing any kind of brake upgrade, I'd make sure it includes beefier rotors. What good are six-piston calipers if they'll just warp the rotors more readily?

 

[Ilikemtb999]

Warped rotors is a myth.