If you're like us, your rig is older, and this means it probably sports rear drum brakes. Sure, they work OK, but the reality is that they suffer from some inherent flaws. Most notably, they're heavy, they retain heat and they lose some stopping ability when they get wet. This is why modern disc brakes are so desirable. They're lighter than a comparable drum brake, they dissipate heat far better and they retain their effectiveness even when wet.
It's for these reasons that we wanted to say adios to the rear drum brakes on our '99 Chevy Tahoe. Actually, the other reason is that we've fitted the SUV with 35-inch-diameter tires, and this has taxed the stock braking system even further, so an upgrade was crucial and welcome.
Enter Stainless Steel Brakes Corporation, which makes rear disc-brake upgrade kits for a number of trucks and SUVs. In most cases these kits are designed to simply bolt in place of the stock drums. The company also makes brake kits that allow you to fit larger disc brakes under your disc-brake-equipped vehicle. We ordered the standard rear disc-brake kit (PN A126-4), which includes everything needed to upgrade the rear brakes on our Tahoe. The kit includes 45mm single-piston aluminum calipers, 11.61-inch-diameter vented rotors with Turbo slotting, Firm Feel master cylinder that eliminates the Tahoe's inherent spongy brake feel and new rear brake lines, hardware and instructions.We completed this driveway install in about four hours. After the pads and rotors broke in and we coaxed the last of the air from the brake lines, we're pleased to report that braking has improved, and, thanks to the Firm Feel master cylinder, we've got a much firmer pedal feel. Makes us feel like dancing.
The first step in installing the new brakes was to raise the truck and remove the wheels and tires. With these out of the way, we could remove the stock drum brakes. In order to remove the stock backing plates on our 10-bolt axle, the axleshafts must be removed as well. Once they're out of the axlehousing, the four stock backing-plate retaining nuts and bolts and the backing plates can be removed from the mounting flange on the axlehousing. The new caliper mounting plates, caliper mounting straps and rotor splash shields go on next (shown), and then the axleshafts are reinstalled in the axlehousing and the rear axle cover is reinstalled. Don't forget to install a new differential gasket and the correct grade of gear oil.
The new calipers slide into place over the rotors and they're secured with the supplied 12mm bolts. The block end of the flex brake hose is affixed to the caliper using the supplied hollow banjo bolts and copper washers. The new brake lines are then installed in place of the stock lines and the parking-brake cable is connected to the new calipers. Due to differences in brake-line routing on Tahoes, SSBC includes longer brake lines with this kit. We had to shorten and flare the lines, which added some time to our install. Also noteworthy is that our Tahoe has a 6-inch suspension lift and this required that we let all the slack out of the parking-brake cable at the adjuster of the framerail so the cable ends would reach the new calipers.
The new Firm Feel master cylinder bolts in place of the stock unit to provide the proper pressure and fluid volume for disc brakes. The new unit requires that you reverse the attachments of the brake lines at the master cylinder. The new unit must be bench-bled after it's filled with fluid (shown), and the hoses and instructions to complete this step are included with the kit.
The stock distribution block must be modified to increase rear-brake pressure. This is accomplished by removing the end nut on the distribution block to allow access to the internal spring and rubber seal on the piston (shown). The spring and rubber seal are removed and the piston and nut are then reinstalled. The final steps to complete the brake install are to fill the braking system with fluid and follow the instructions to bleed the system and check the new lines for leaks.
Here is the kit installed. Not only is the rear disc much more effective at dissipating heat, it also looks a lot better than a rusty old drum, especially if you have open wheels to show off your new stoppers.