Admittedly, the vast majority of classic truck ownersconvert to disc brakes in the rear for one reason and one reason only: to get rid of the unsightly drums and replace them with something that looks similar to the front when looking between the spokes. But have you ever thought about all of the other advantages there are to adding rear disc brakes to your truck?
Front brakes can only do so much. Most rear drums do very little for stopping power, which is usually why a set of rear shoes will last two to three times longer than the front pads. By adding rear disc brakes, you can add as much as 30 percent more brake force to your braking system. Disc brakes offer a number of advantages over drum brakes. The design of disc brakes dissipates heat much more quickly than drum brakes. Also, heat causes the disc to expand, which has no effect on braking ability, but when the drum expands, it increases the amount of travel required for the shoes to apply effective stopping force. When disc brakes become wet, the large majority of the water is spun off of the disc during rotation. In a drum brake setup, water can become trapped inside the drum and act as a lubricant between the drum and shoes, causing water-induced brake fade. Since disc brakes apply equal force through clamping, they are also much safer during straight-line braking. On a practical note, disc brakes are much easier to service than drum brakes and are lighterweight.
Stainless Steel Brakes Corporation has over 30 years of experience in brake system upgrades. Like in our case with Project Old School (which is rapidly becoming less and less old school), SSBC has several stages of conversion kits available for different vehicle models. We chose the Force 10 four-piston caliper and 13-inch rotor for the front, which we'll be telling you about next month. This month we focus on the rear where we used conversion kit A126-1 to convert our GM 12-bolt rearend. This is a kit that is designed to fit within any 15-inch wheel. Since this is technically a kit for '73-and-later trucks, we also needed to update the axles with five-lug units, which we picked up from Classic Performance Products. Follow along as Installation Jason (aka Jason Scudellari) helps us make the transformation. And stay tuned for next month when we tackle the frontend--give Old School a new look--and even do a little testing.
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 Stainless Steel Brakes Corporation...  Stainless Steel Brakes Corporation offers this rear brake conversion kit (PN A126-1) for '73-87 Chevy 1/2-tons, but it should also work on any of the earlier models with the same axle flange (assuming you're willing to convert to five-lug axles). The kit comes complete with 11 1/2-inch rotors, which we ordered with SSBC's optional Turbo Slotting and Xtra Life plating, calipers, powdercoated brackets, all the necessary hardware, and detailed instructions with special sections on torque specs and bleeding procedures. |
 The SSBC rear caliper is a...  The SSBC rear caliper is a single-piston, cast-iron unit. The piston measures 45 mm, and it features a built-in parking brake. We ordered ours with a black powdercoated finish to match the fronts. |
 Pad replacement is not an...  Pad replacement is not an issue because these calipers are designed after units found on mid-'80s SVO Mustangs and were later used on Lincolns, so the part numbers are supplied and readily available. Of course, SSBC replacement pads and rotors are available as well. |
 Once in the Primedia Tech...  Once in the Primedia Tech Center, Jason raised Old School up on the lift and pulled the wheels. The first item to be removed was the stock drum. |
 Next, we unbolted the diff...  Next, we unbolted the diff cover and drained the fluid into a pan. Then Jason pulled the pinion shaft by removing the lock bolt. |
 Now the axles could be pushed...  Now the axles could be pushed inward, allowing the C-clip to be removed from each end. |
 Jason then slid each axle...  Jason then slid each axle out of the housing. These will be replaced on this truck for five-bolt units. |
 The removal of the axles gains...  The removal of the axles gains access to the backing plate bolts, which were the next to go. Once the four bolts were removed, off came the backing plates. |
 We also pried out the axle...  We also pried out the axle seals to inspect the bearings. They rolled smooth and had no visible wear, so we left them in place and covered them as we cleaned up the ends of the housing. |
 Classic Performance Products...  Classic Performance Products offers these stout five-on-five axles for converting to the five-lug pattern. We also picked up the new seals and studs at this time. |
 With the housing ends cleaned...  With the housing ends cleaned and painted, Jason pressed the new axle seals into place with a large socket of like diameter. |
 The caliper mounting plates...  The caliper mounting plates install over the end of the axle tube against the mounting flange. It looks crooked, but the correct position is with the plate tilted toward the front of the truck. |
 With the four supplied bolts...  With the four supplied bolts installed through the holes on the mounting plates, the splash guard slid into place with the open end pointing toward the rear of the truck and the lip pointing outwards. |
 After the splash guard, a...  After the splash guard, a 3/4-inch tubular spacer was installed over each of the four bolts. |
 The caliper mounting straps...  The caliper mounting straps were next. They're identical and one goes above and the other below the axle housing facing rearward and toward each other. The mounting bracket for the brake line also fits on the top rear bolt. |
 Next, the new axles were slid...  Next, the new axles were slid into place. We were careful not to disturb the new seals. |
 The C-clips were slipped over...  The C-clips were slipped over the end of each shaft before the pinion shaft and lock bolt were reinstalled. |
 Then the diff cover was cleaned...  Then the diff cover was cleaned up and treated to a bead of RTV sealant before being reinstalled. |
 Jason then torqued all of...  Jason then torqued all of the bolts to the required 70 lb-ft. |
 Next, the rotor was installed...  Next, the rotor was installed onto the axle and held in place with a lug nut. |
 The caliper was slid over...  The caliper was slid over the rotor and in place over the mounts. |
 Jason installed the caliper...  Jason installed the caliper mounting bolts and torqued them to 100 lb-ft. |
 We forgot to include them...  We forgot to include them in the product shot, but we also upgraded to steel-braided lines, which were installed on the calipers using banjo bolts and torqued to 20 lb-ft. |
 The opposite end was secured...  The opposite end was secured to the mounting brackets using the provided clips. |
 Jason bent up new lines to...  Jason bent up new lines to run along each axle tube. |
 And it was a good thing too...  And it was a good thing too because they were replacing these mangled lines. |
 One end was secured to the...  One end was secured to the existing "T." |
 And the other end was installed...  And the other end was installed into the braided hose at the mounting bracket. |
 The SSBC rear kit definitely...  The SSBC rear kit definitely brings this old 12-bolt up to date. We can't wait 'til next month to show you the Force 10 system on the front and do a little testing. We recorded some 60-to-0 braking distances before installing the new booster/master combo, so we were really curious to see how many feet we could shave thanks to these improvements. |