What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Sir_Hiro

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mikez71

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Not sure there is much advantage, but...
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Rotor -tiny- bit larger.
4 pistons spread out instead of 1.
Calipers don't use sliders. (Maybe a little better feel or responsiveness?)

Braking force should improve a little bit..
(Stock piston is 51mm x 2 51mm x 1, 2020+ are ~42mm x 4..)
Not sure if you calculate both sides of pistons?
But one half caliper has an area of ~260mm^2 combined vs ~160mm^2 for the single larger cylinder...

Surface area of stock brakes ~320mm^2
Surface area of '20+ 4 pots ~525mm^2.


The not-so-good,
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These calipers protrude further, often requiring spacers or new offset wheels..
But I have some later model wheels that should fit propery.

May need centering washer behind the caliper..

I'm wondering if I should get the OEM composite rotor which is 28mm thick (possibly FNC treated).
Or Delco/centric/bosch full cast rotors that are 30mm thick.
The 28mm gives an extra mm of clearance, that might make the difference between washers or not..

I ordered 30mm thick discs.
 
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Scrappycrow

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The not-so-good,
-------------------
These calipers protrude further, often require spacers or new offset wheels..
But I have some later model wheels that should fit
Include your spare in the scenario.

If the spare will still fit on the back, at least, you'd have to do a double tire change for a flat on the front (which was the case when I went to discs up front on my '57 Chevy and only had a 14 inch spare). If it won't fit either front or back, it ain't of any use.
 

the_tool_man

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These calipers protrude further, often require spacers or new offset wheels..
But I have some later model wheels that should fit already.

May need centering washer behind the caliper..

I'm wondering if I should get the OEM composite rotor which is 28mm thick (possibly FNC treated).
Or Delco/centric/bosch full cast rotors that are 30mm thick.
The 28mm gives an extra mm of clearance, that might make the difference between washers or not..

But I'll probably just stick 30mm thick discs in there..
The calipers need to be centered laterally on the rotor, because they're rigidly bolted onto the spindle and don't slide to compensate for alignment or pad wear. The only way to know for sure how thick any spacers would be is to assemble and measure. I haven't installed these myself. But I'm not aware of anyone installing them without spacers. I recommend precision spacers, not run-of-the-mill SAE or whatever washers, which can vary in thickness by quite a bit.

Wheel fitment is a huge issue. The newer platforms changed the OEM wheel offset, which provides more clearance to the caliper than most GMT900 OEM wheels. I have lobbied for someone to make a template of the caliper and hub cross section so that people can check their wheels. But no one has done it yet AFAIK. You have to either scour the internet for someone who happens to use the same wheels that you do, and has upgraded, or be okay with using spacers or swapping wheels. Some have either ground off the bulge on the outboard side of the caliper, or added 1/4" spacers, or both. It's a bit of a gamble.
 

mikez71

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Include your spare in the scenario.
Thanks for reminding me!

That reminds me of the time I bought this old ford turbocoupe.. 2.3 turbo was great!
Then I got a flat on the highway and the spare would not fit!

If the spare doesn't fit, I'm buying a new spare. Forget about the double wheel change!

The calipers need to be centered laterally on the rotor, because they're rigidly bolted onto the spindle and don't slide to compensate for alignment or pad wear. The only way to know for sure how thick any spacers would be is to assemble and measure. I haven't installed these myself. But I'm not aware of anyone installing them without spacers. I recommend precision spacers, not run-of-the-mill SAE or whatever washers, which can vary in thickness by quite a bit.
Precision spacers sound good. Haven't sourced them yet..

I think I heard one guy claim he didn't need spacers on his GMT900 but he did on his GMT800.

And I thought someone mentioned they might not be needed, but they wanted to center the rotor.
1mm off isn't going to bother me, so long as the piston doesn't get cocked when the pads are worn down.
(I prefer not to have to keep spacers around in case I lose one... )

Hopefully can install in a week or two...
 

LSCALADE

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I can chime in, I have done the brake upgrade on both my Escalades and now everytime I drive my Suburban I cant stand how spongy the pedal feels and how reduced the brake bite is, so they do work excelent and are worth the effort even if you have to deal with wheel spacers etc.

The extra force preovided by them gives you a very nice firm pedal that can be very easily modulated.
 

Scrappycrow

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I was up with some indigestion and instead of riling myself up with doomscrolling, I figured I'd work on the parts list for the Tahoe.

The biggest ticket item on my list is the Luk TorCon TC0017 converter, and I saw RockAuto has it for $348.79. That's much better than Summit's price of $491.99 ($467.39 w/ military discount), so I was about to put it in my RockAuto cart, but figured I'd check elsewhere. It just so happens that AutoZone has a "20% off over $100" 24-hour coupon code "GETITDONE," which makes it $342.39 from them, so with tax, it's $368.93 to my door.

Ordered! :D

Oh, dang -- with that 20% off, I should have added more stuff to the order. :( Well, I definitely have more than $100 in parts I need, so time to start another order...
 

lowh07

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Got a “new” key fob. I’ve been using a 2015 style retrofit for about 4 years, but it was looking pretty bad and it has some extra buttons I don’t need. Also those buttons seem to press more easily (when I don’t want them to) so I’d always walk out to rear hatch being open.

Felt like returning to the old simple one. I got this from NorthCoast Keyless and picked the “lightly used” option (it’ll get scratched up anyways). $24.94 shipped and it appears to be an oem one

IMG_0705_SnapseedCopy.jpeg
IMG_0706_SnapseedCopy.jpeg
 

j91z28d1

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had checked the catch can about a month ago, wasn't bad. few oz of normal looking oil with about 2500mil on it. Just changed it at 3k and checked it again. week or 2 of cold Temps below 32 and short drives. crazy amount of condensation to me since I've never seen any before.

Img_2026_02_03_08_37_21.jpeg
 

Sir_Hiro

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had checked the catch can about a month ago, wasn't bad. few oz of normal looking oil with about 2500mil on it. Just changed it at 3k and checked it again. week or 2 of cold Temps below 32 and short drives. crazy amount of condensation to me since I've never seen any before.

View attachment 477493
I keep debating on adding one to mine. Seems easy enough.
 

mikez71

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Realized upper part of 07-09 and 10-14 door panels are different. (So I'm not swapping halves)

Brackets different too. I had to drill a couple slots on the bracket.
There is a nut plate, with tabs that poke through the door and metal bracket...(two vertical bracket slots seen on right panel)
'07-'09 must not use that nutplate as the bracket has no slots. (left panel)

IMG_0848.jpeg


Old handle feels much better without the seam!
 
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SpareParts

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had checked the catch can about a month ago, wasn't bad. few oz of normal looking oil with about 2500mil on it. Just changed it at 3k and checked it again. week or 2 of cold Temps below 32 and short drives. crazy amount of condensation to me since I've never seen any before.

View attachment 477493

Checked mine today after about a month and the exact same stuff in mine, About a cup worth. Same type of driving also.
 

lowh07

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My alternator finally gave up... pretty sure it's the original one at 198k. I think my nitrous bottle heater put it over the edge. Today I heard it whining very loudly, followed by a really bad smell, followed by my gauges and stereo cutting out and seeing smoke come out from under the hood.

Ordered a Mechman 320 amp "racing" alternator and some 0 gauge cable from KnuKonceptz to do the big 3 upgrade. I want it to be future proof for the heat exchanger pump and beefy fuel pump (and probably other things I'm not thinking about).
 

Doubeleive

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after changing the door handle and vacuuming the rear of the truck I had a very annoying rattle in the back couldn't quit figure it out so had my son ride in the back and had him pinpoint it, discovered it was coming from behind the passenger rear side lower panel (where the rear ac/heater box is) so pulled out my subs the 3rd row seats, pulled all the panels out and the rattle disappeared......put it all back together and rattle gone, so really don't know what it was but thank the gods.....
it was a buzz buzz buzzz about 30mph+, super annoying
 

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