The Hawk HB921Y.670 is a rear brake pad set built on the manufacturer's LTS (Light Truck and SUV) compound, a Ferro-Carbon friction formula sold for light and full-size trucks, vans and SUVs. The manufacturer says the compound gives a strong and balanced initial bite, hot or cold, along with greater fade resistance and low dust output. Because Hawk compounds are meant for metal rotors, Hawk pads are designed to work with Iron/Metal rotors, so this set is for a standard cast-iron rear rotor setup and not carbon-ceramic.
The case for paying for LTS over budget pads is wear life and consistent braking on a heavy truck. The manufacturer lists excellent pad & rotor life for this compound. The rear fitment is listed for 2019–2020 Silverado 1500 and Sierra 1500 models and is broken down by trim, engine, and whether the truck has the OE wear sensor, so confirm your configuration before ordering. For installation, owners on user forums report that you should enter brake service mode, and you will need a caliper retractor tool since the calipers cannot be compressed by hand. Owners also report that one set of pads wore far unevenly, with the inboard pads much more worn than the outboard ones, so inspect both sides.
No. The manufacturer states that its compounds are designed for iron or metal rotors and are not compatible with carbon-ceramic rotors.
Per the manufacturer, apply a thin layer of silicone anti-squeal lube only to the back of the pad. Getting it on the rotor face or the friction surface can cause the pad to glaze and reduce stopping performance.
Yes. The manufacturer explains that proper bedding brings the pad surface up to temperature and creates a transfer film of friction material on the rotor, which increases stopping performance and can reduce pad and rotor wear.
This is a hands-on rear brake job, and the electronic parking brake is the main gotcha. Per the manufacturer, install the brake pads properly and check the brake fluid. Owners on user forums say the rear caliper motors must be retracted through brake service mode before the caliper comes off, and one owner who removed the caliper first ended up with warning lights and a reduced-speed fault that took a dealer-level reset to clear. Check that rotors are not badly worn or damaged, since the manufacturer advises against using worn rotors with new pads, and clean any reused rotor surface with fine sandpaper or steel wool before installing. For bedding, the manufacturer says to allow 15 minutes for brake system to cool down and not to drag brakes while car is moving during break-in procedure. Owners on user forums describe making 6-10 slow-downs from approximately 30-35 mph to 5 mph, applying moderate pressure, without coming to a complete stop, then letting the system cool before normal driving.
