Brake Upgrade Help

[Matthew Jeschke]

Update: It looks like the CTS-V brake upgrade requires a larger wheel (possibly 20"?). Might be better to do the new Silverado brakes if going that route and having a smaller wheel. The CTS-V looks like but cannot confirm, would require an adapter plate as well. Very little info on swapping these into a GMT800 although a popular swap on other vehicles.

I'm back to the original CMT900 brake upgrade. My question on that upgrade is, I'd like the AC Delco Gold calipers. However, they are 150% the cost!

AC Delco Gold GMT900 Front Calipers

The only thing I think is different are some of the seals??? I'd venture a person could rebuild another caliper with the upgraded seals??? I could care less about the powder coating... Any idea?

 

[Marky Dissod]

If you want to be sure of getting better seals, ask for the 2010-2014 Tahoe PPV calipers.
Those come with high temp seals.

 

[Matthew Jeschke]

I got my upgraded brakes. They're from GMT900 Silverado. After further research I see up to 2018/2019? the part numbers are the same for the calipers. I bought them used and am rebuilding them. Did my test fit on passenger side and it bolts up perfectly to the steering knuckle.

Only thing, where do I get the larger dust shields to protect the larger rotors?

GM PN 25918337 (left) and PN 25918338 (right) are discontinued.

 

[Marky Dissod]

I got my upgraded brakes. They're from GMT900 Silverado.
After further research I see up to 2018/2019? the part numbers are the same for the calipers.
I bought them used and am rebuilding them. Did my test fit on passenger side and it bolts up perfectly to the steering knuckle.

... where do I get the larger dust shields to protect the larger rotors?

GM PN 25918337 (left) and PN 25918338 (right) are discontinued.

At risk of jinxing myself ... so far ... my GMT800 dust shields have sufficed ...

 

[Matthew Jeschke]

I am going to stick with the GMT800 ones as seems oddly nobody makes the gmt900 ones anymore. If I am lucky to find a gmt900 in the junkyard I will snag them but for whatever reason I NEVER see gmt900 in the junkyard here.... Did they make far fewer gmt900s?

 

[Marky Dissod]

... going to stick with the GMT800 ones as seems oddly nobody makes the gmt900 ones anymore.
If I'm lucky to find a gmt900 in the junkyard I will snag them,
but for whatever reason I NEVER see gmt900 in the junkyard here ... Did they make far fewer gmt900s?

Maybe the GMTK2xx & GMT1xx are teaching people to take better care of their GMT900s?

 

[Matthew Jeschke]

hahahaha yeah, interior quality dropped off around the GMT800... but mechanical complexity got a little out of hand after the GMT900.

I'd still like to find this dust shields. Nowhere on eBay though and the part number isn't found anywhere on the internet. The old ones are 0.8" shorter, likely is fine, maybe fine regardless.

 

[Matthew Jeschke]

Anybody paint their calipers? I may have jumped the gun. I use rustoleum a lot to paint various car parts. I used it on my control arms and worked like a champ! However, cleaned up the calipers then sprayed them with rustoleum and it doesn't seem to like to bond. With little effort the paint comes off. I also forgot probably calipers use special paint as the brake fluid will dissolve paint.

 

[Marky Dissod]

I've never painted calipers myself. My mech insists you're supposed to use special paint on them.

 

[Matthew Jeschke]

Ended up saving notes from this project on my website:

GMT900 brake swap - Matthew Jeschke

My Tahoe is the GMT800 truck chassis from General Motors. The rear brakes always seem overworked and hard braking leaves something to be desired. If you also have a 4 wheel drive GMT800 SUV and are wanting to upgrade your brakes then this is the right place. Poor brake performance I’m told the...

matthewjeschke.com

I need to organize more of my notes! I've probably got something ridiculous like a TB of photos and videos on my project to build up this truck. They're just sitting on my hard drive.

 

[Paul_Kaos]

If you want 17's you'll have to get some off a 19+ or get aftermarket with the 19+ offset and back spacing. They do still run 17's on the new trucks.

Working really hard in this thread not to say *wheel spacers* lol

Basically any 17s will clear with the right offset. All wheel spacers do is adjust offset. Theyre not going to kill your wheel bearings any more than a similar backspaced wheel...

Will h2 wheels clear the 4pot fixed fronts without a spacer?

Also... I see the 2pot tahoe pbr back on a 13" and the 4pot fixed front on a 13" are the biggest oem anything that fits under a 17...

Anybody ever made brackets to use that same rotor combo, but swap the 4pot front caliper to the back, then force the bigger caddy 6 (or is it 5?) pot caliper over the 13" front, under an aftermarket 17" setup?

I think you could drive those with a hydroboost right?

 

[Paul_Kaos]

Working really hard in this thread not to say *wheel spacers* lol

Basically any 17s will clear with the right offset. All wheel spacers do is adjust offset. Theyre not going to kill your wheel bearings any more than a similar backspaced wheel...

Will h2 wheels clear the 4pot fixed fronts without a spacer?

Also... I see the 2pot tahoe pbr back on a 13" and the 4pot fixed front on a 13" are the biggest oem anything that fits under a 17...

Anybody ever made brackets to use that same rotor combo, but swap the 4pot front caliper to the back, then force the bigger caddy 6 (or is it 5?) pot caliper over the 13" front, under an aftermarket 17" setup?

I think you could drive those with a hydroboost right?

Is this even feasible? I cant remember what the back of the caddy calipers looks like?

[Edit] anything is *feasible* and its a great caliper combo but im asking if there is room to drop the caliper down via the casting idk if theres a bracket from memory or could it easily by cut down and redrilled lower etc...

If junkyards were like the south ten years ago Id buy cores and cut some up for lols to see

 

[Marky Dissod]

No clue how to make 6piston calipers and their corresponding rotors fit inside anything under a 20" wheel.

If you carefully machine the excesses off the GMTK2 caliper and its 13.5" rotor, and space everything just so,
I've READ that there are SOME 17" wheels that can be finagled to work with the GMTK2 caliper & rotor,
but 18" wheels just make everything so much easier.

 

[Paul_Kaos]

Dude there are whole threads if people talking about 17"s on the 2020 front brakes the ******* spares on the 2020 trucks are 17 they still put 17 on those trucks stop ******* lying to people on the internet

Its an *offset* issue

The 13" rear setup fits under factory *16*s

A fixed caliper isnt taller, its *thicker*

Its an offset issue stupid

You need wheel spacers and then any 17" fits over 2020 4pot calipers

 

[buckwild27]

Don't go stringing up the rope but I believe the spare 17's in some cases are ment for the back only. So if you get a front flat you have to take one off the back and put the spare on the back. I personally got a 20" wheel from the PPV tahoe and made it my spare.

 

[buckwild27]

Dude there are whole threads if people talking about 17"s on the 2020 front brakes the ******* spares on the 2020 trucks are 17 they still put 17 on those trucks stop ******* lying to people on the internet

Its an *offset* issue

The 13" rear setup fits under factory *16*s

A fixed caliper isnt taller, its *thicker*

Its an offset issue stupid

You need wheel spacers and then any 17" fits over 2020 4pot calipers

You need to back it down about 25% bud. Some of us don't want to run wheel spacers we prefer a direct bolt on.

 

[Paul_Kaos]

The inside space on the wheel is 16" at the center, the disk in question is 13"... The 2020 front rotor isnt 13.5 its 13 same as our backs, it might be a smidge over because its some mm number but when I specifically looked it up in inches they round them to 13"

*My whole hand slides between the slider caliper and the wheel in the back*

Youre telling me the fixed caliper will rub in that space?

Or am I messing up somebodies con they ran on the wife for why they had to donkify their truck "for safety" lol

I use it offroad any benefit of better brakes is immediately degraded by turning it into a hotboy takeover heap...

Literally there are entire discussions on this topic

Youre trying to argue about things I already know for facts

Why?

We should ban donk wheels on trucks if its a car drive a car you dont need a truck to drive on pavement lol...

No vehicle needs wheels larger than 22" sans heavy equipment lol...

 

[Paul_Kaos]

Sorry I just get sick of cults

20" wheels ruin a truck for me unless youre talking about a 2500 or bigger on like duce&a½ axles or something lol

Or its a Mega truck or anything else where youre stuffing them in a tire over 44" in diameter lol

These trucks take a 35, a 37 with glass. By the time youve got a 40 actually *inside* the wheel opening youve cut away most of the truck and youre half framing a cab lol... Ive seen the inside of the back half of "Loki" and we are not doing all of *that*

Everybody on these truck forums just wants to bling up their 25yo grocery getter so they can be "ballers" at the EBT Store/Take-Over lol... Chop cam on a 4l60 with 26" wheels either donked out or their wides and only the front is lifted. Probably underglow neons (oh my bad "rock lights”)

Oh, or its literally just a Goodguys Boomers Drag vehicle because he cant afford a Nomad or a Panel Truck...

Or its literally Hank Hill Stock ”OEM quality delivers slow and dependable performance and the tortoise and the hhair taught us that slow and dependable always wins the race, I tell ya hwat!"

I wish these trucks were more popular in cool truck things but when you go to look at cool truck things you are just short if told to buy a f*ckin Raptor or a Toyota or something made by a company who gives a **** about us...

 

[Paul_Kaos]

Oh yeah and the subwoofers... Forgo any benefit of driving a 6klb freight vehicle so we can force everyone around us to hear our credit score...

"Let me sing you the song of my people"

Its literally never Mozart...

Its some complexion of "shops at Walmart” (pick one theres three shades of shit in this toilet )

 

[Paul_Kaos]

Backed down enough M8?