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’re wanting to upgrade your GMT800 brakes then this is the right place.
Poor brake performance
I’m told the GMT800 has a system where under light braking the rear brakes are only applied. Maybe the case as the rear brakes get super HOT if I do light braking in prolonged conditions such as coming down a mountain.
This lead me down a rabbit hole where I continually pull over and check heat on front and rear brakes. One thing is clear the rear disc brakes work much harder on my truck. Searching forums I’m not alone. People are using up rear brakes faster than fronts. Typically you’d go through multiple sets of front brakes before your rears ever need changed on a vehicle.
Some (if not all?) of the GMT800 pickup trucks came with larger brakes. However, the SUV variants didn’t seem to get them till the GMT900 chassis was released. I theorize the original 16″ wheels on those vehicles wouldn’t fit the larger rotor so they stuck with the smaller brakes until they released the next revision GMT900 chassis.
Brake tuning
One should be careful installing new brakes especially if ONLY upgrading front or rear. There’s a brake balance built into the system where the rears brake less than the fronts. If you create an unbalanced condition if the rears lock before the fronts. Specifically it may oversteer for which can lead to complete loss of control of the vehicle. Ever try pulling the parking brake at high speed? Then you know what I’m talking about.
Without theoretical models of the truck itself I cannot say with much certainty what will happen swapping parts like this. However, I can say it’s a VERY popular upgrade for which I’ve not heard of any serious concerns and it slightly increases braking torque only to front wheels by going from a 12″ rotor to 13″ rotor.
There are people are swapping MUCH larger brakes from the C6 Z06 Corvette, the first generation Cadillac CTS-V, or the 4th generation Silverado. These are not direct fitment although the 4th gen Silverado brakes are close. You’d want to make sure your brake balance is good with these larger brake systems. Most likely you’d have to tune brake bias and or swap the rear brakes as well if you choose to do this. I’d say if you do the 4th gen Silverado upgrade you’d want the rear brakes as well.
GMT800 versus GMT900
If you do this swap I’m told you need to use brakes from 2010 or later GMT800 to ensure they are direct fitment. Otherwise they’re some jury rigging you have to do to pull it off. Additionally, some of the GMT800 pickup trucks already came with a very similar if not same front brakes.
Another plus for this upgrade is you can use 17″ rims from the GMT800. Other proposed upgrades require 18″ to 20″ rims! I off road and appreciate the extra sidewall the 17″ rims afford me so it’s a hard sell for me to go to larger brakes than the GMT900.
| GMT800 (2001 Tahoe) | GMT900 (2010 Tahoe) | |
| Caliper Pistons | 2 | 2 |
| Rotor diameter | 12″ | 12.99″ |
| Rotor Thickness | 1.14″ | 1.18″ |
I’ve been unable to confirm master cylinder brake bias between these models of trucks. Specifically how much pressure is applied to the front versus rear. With this information you can get an idea of energy dissipation ratio between the front and rear axles. Brake bias is pretty well always higher on the front axle say 55% of braking is done with front wheels while 45% is rear.
Part numbers
First I upgraded my brake hoses. They stopped making the GMT800 truck chassis in 2006. That makes these trucks all well past due for new brake fluid and brake hoses. My Tahoe is a 2001 so I inspected all the metal brake hoses and replaced all the rubber lines.
I couldn’t recommend Classic Tube enough. They have a steal braided brake hose kit that’s direct fitment for our trucks. It was slightly more than factory rubber hoses but much higher quality. I highly encourage this upgrade when you change your hoses out. If you plan to do a brake upgrade other than the GMT900 proposed here you may also need to get an adjustable master cylinder to tune your brakes.
I’m going with AC Delco Gold part numbers for my swap. They are AC Delco Gold 18FR2659N (right) and 18FR2660N (left). Those are it! Buy the calipers w/ brackets and a set of rotors & pads. I’ve yet to do the swap as I’m going to run my pads down then do this when I service the front brakes next! Just pick yourself some pads and rotors from a 2010 GMT900 and you’re good to go.
As a side note, I’m not too big a fan of aftermarket parts when I can avoid them. Rebuilt parts are okay but I prefer to rebuild them myself. My ultimate goal is to buy the calipers at a junkyard and rebuild them myself. However, I’ve yet to find them. Otherwise, when comes time for new brake pads I’ll upgrade do the GMT900 brake upgrade.
Related platforms
This project isn’t limited to my my 2001 Chevy Tahoe. It should work on any of the following so long as you have the smaller 12″ front brake rotor. Otherwise, probably not worth it if you already have 13″ rotors.
Most if not all the GMT800 Suburban, Tahoe, Denali, Yukon, Escalade have the 12″ rotors
Years 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
Most of the GMT800 Pickup trucks seem to already have the 13″ front brake rotor but if they don’t this would be a viable upgrade.
Feel free to message me with questions.
