4 Piston Big Brake Upgrade from 2019-20

[Dantheman1540]

Yes, you may be right, but this is the 2000-2006 section of the forum. So this thread was started to suggest an upgrade to the GMT-800 2-piston brakes which are grossly inadequate. The GMT-900 already had larger brakes (and rotors, I believe) so I wouldn't have expected as much difference. Plus, if you just put them on yesterday, are they even burnished yet. If not, they will probably improve over the first couple of weeks of driving.

I totally agree with SRQ that they will get a little better as they wear in. I was surprised at how little of a difference they felt at first but after a few weeks, they seem much more effective.

But still, they aren't gonna stop like hitting a wall.

 

[SRQYukon]

If anyone thinks this upgrade is going to be equal to Brembo or Wilwood big brakes with 6-pistons and mega 16" rotors, then they're engaging in wishful thinking. But for those that want much better braking for less than 1/2 the cost of these aftermarket brake kits, it's an option. Once I get mine installed and dialed-in, I'll post a comparison between the original GMT-800 brakes and the 4-piston upgrade.

 

[1BADI5]

I just installed these brakes on my dad’s 2012 yesterday. I drove it and they do feel better than the stock GMT-900 brakes but it isn’t a massive difference like going to the Brembos. If you’re expecting Brembo performance from these, you will be disappointed. They are an upgrade but it isn’t worth buying new wheels just to fit these brakes in my opinion, they aren’t that good. We already had AT4 wheels on his truck so it made sense. I will not be bothering with these for my Yukon since they don’t work with my wheels. I suspect similar performance could be had with EBC Yellowstuff pads in the stock 900 brakes.

Now throw some YellowStuff pads in those new calipers, bet that would be a solid set up.

 

[ivin74]

I think this might be the route i will go........unless someone else wants to be the 99-13 guinea pig???

I had a buddy of mine do the ctsv brake conversion and he stated that the ctsv brake pads had less contact surface in his Siera brake rotors. Not sure how much effect that would make on stopping these 5k lbs rigs. Something to think about.

 

[lucas287]

On a different forum a self-proclaimed brake expert (worked in the industry for decades) chimed in about this new setup. My biggest takeaway from his contributions were that he was really impressed with the GMs new brake pad formulation. He claims that it's one of the highest friction coefficients to come on an OE-vehicle - HH. As others have mentioned before, these new ceramic pads will require quite a bit of break-in with that level of friction. But - should be excellent once fully bedded.

I propose that anyone who leaves a review of their thoughts also share the specific pads they used since we all know how big of a factor that plays.

Side note - i'm not a Tahoe, or Yukon, guy. I have a '16 Silverado with the little 6.2. I have all the parts sitting in the garage waiting for some free time so I'll be sure to share my thoughts when the time comes!

 

[91RS]

I’ve never had brakes improve a noticeable amount after being bedded in but regardless I was comparing the stopping power to the Brembos which stopped significantly better from mile 1 (I was comparing to the Brembos because I believe someone was saying earlier in this thread that these brakes should be close in performance and they are not). I understand the forum I’m in. I said these brakes are better than the GMT-900 brakes BUT aren’t a value if you have to buy wheels just to fit them. Unless you were already buying wheels anyway, just get the GMT-900 brakes and Yellowstuff pads.

 

[SRQYukon]

I completed the 4-piston upgrade this weekend. So far I'm impressed with the performance, though not able to thrash it much yet. Since we also replaced the rear differential at the same time, I'll need to complete the break-in before I see how it works for trailering. For the cost, I say it's well worth the investment. I cannot comment on comparisons to Brembo, Wilwood, Baer, or other big brake upgrades, because I've never had any of those. Here are some observations:

It was actually one of the easiest upgrades to do.

The whole installation took about 2 hours, which included replacing the brake lines and bleeding the system. That's with an assistant for the bleeding. This assumes you've test fitted your wheel and there are no clearance issues. I had already spent another three hours ahead of that smoothing the calipers and painting them.

I did go with R1 Concepts drilled and slotted rotors and their Optimum OE pads. I doubt that adds much beyond stock braking performance, but I've had better success with d&s rotors when it comes to warping from heat. The set I took off had 130k miles and had never been turned and were still running true.

The only tricky part is getting the calipers centered. One standard washer was not enough, and two were too much. We scouted around and found some thinner washers and put 1 thick washer and 1 thin one. That was perfect. So if you do this, have an assortment of 1/2" washers of varying thickness on-hand to try.

I'll post more later, once I have used them for a while under varying conditions. I won't mess around with measuring stopping distance, but I will post my review based on my driving experience compared with the previous 214,000 miles with the stock brakes.

 

[Fjs0001]

I made some 0.133" spacers to center my calipers on the rotors. For mock up, I stacked 0.365" of washers to use as wheel spacers and the 2010 22" Escalade wheels are 0.14" away from touching the bump on the caliper.

The caliper bump is 0.3" tall, so if I grind it off I should be about 0.075" away from the caliper without using spacers. How close is too close? I think I can only get away with a 1/8" wheel spacer and still have proper support between the hub and wheel. I don't care about these rims enough to spend big money on spacers. I'm going to grind down the calipers unless I find a used set of spacers somewhere.

Now I'm trying to decide if I want to powder coat these calipers or just spray paint them.

 

[Dantheman1540]

These brakes impressed me again last night, I was coming home late and admittedly looking at my laptop when the car in front of me stopped at a green light for no reason. luckily I saw the brake lights and had more than enough time to stop but since I was startled at the odd event I smacked the brakes hard and sent my laptop into the floorboard, kinda forgot how good these things are.

 

[SRQYukon]

I made some 0.133" spacers to center my calipers on the rotors. For mock up, I stacked 0.365" of washers to use as wheel spacers and the 2010 22" Escalade wheels are 0.14" away from touching the bump on the caliper.

The caliper bump is 0.3" tall, so if I grind it off I should be about 0.075" away from the caliper without using spacers. How close is too close? I think I can only get away with a 1/8" wheel spacer and still have proper support between the hub and wheel. I don't care about these rims enough to spend big money on spacers. I'm going to grind down the calipers unless I find a used set of spacers somewhere.

Now I'm trying to decide if I want to powder coat these calipers or just spray paint them.

I think you can go up to 1/4" without losing support. I've been running 1/4" spacers of the rear of my Yukon Xl and towing a 4000 lb. trailer several times a week (for a couple of years) without any issues. You really need to look at how much wheel stud there is beyond the lug seat. 0.14" clearance should be fine. I only have 0.125 and no issue in the first 150 miles. I don't think aluminum wheels have much flex even when cornering.