How To Change Drum Brakes | Autoblog Wrenched
[00:00:00] [Larry] Drum brakes were the first generation of braking systems in vehicles from the early 1900s all the way up to the 1980s and 90s. Most older vehicles still on the road today only have drum brakes on the rear of the car. Here are the tools you’ll need to do it yourself. Drum replacement hardware kit, shoes, pliers, screwdriver, Spring set, wire brush, needlenose pliers, protective eyewear, and of course, brake clean. I’m Larry Kosilla, pro detailer and trainer for the last 15 years.
[00:00:30] But when it comes to what’s under the hood, I’m the student. Follow me as experts teach me how to diagnose, fix, and modify cars on Autoblog’s Wrenched. – Alright, so what’s the difference between disc brakes and these here, drum brakes. – Well the disc brake actually has two brake pads that squeeze together hydraulically through a caliper and create the friction to slow the car down. – Okay. – A drum brake has two shoes which sit with springs on the inside of this drum, and through a wheel cylinder, hydraulically expand and cause the friction
[00:01:00] on the inside of this drum. – [Larry] So a caliper squeezes, and a drum kind of pushes out. – [Spencer] Exactly. – [Larry] Okay. Alright well I’ve done disc brakes before and those went pretty well. Is this the same kind of idea? – Once I show ya how, you’ll be able to do it. – [Larry] It’s important to understand that this is a complicated job that has many different set-ups unique to each respective vehicle, so keep in mind, your specific drum brakes may not exactly resemble the ones show here, and you might need more information or tools
[00:01:30] specific to your car to do the job properly. Remember, our goal with this video is to give you an idea of what’s involved in these types of projects should you choose to replace the brakes yourself. If you’re uncomfortable, simply hire a professional mechanic. First, we remove the drum with two bolts that, once screwed in evenly, will slowly push the drum away from brake assembly. Otherwise, a few hits with a sledgehammer on each side will help dislodge the rusty drum, revealing the pads underneath. For novices like myself,
[00:02:00] Spencer suggested I take a cell phone picture of the brake assembly after I pull the drum off and especially before I start pulling the shoes apart. This is essentially disassembling and then reassembling a big jigsaw puzzle, so a picture is worth a thousand words to a novice. There are a lot of special tools that make your life easy when removing drum brakes, but most can be done with your standard needlenose pliers. Begin by removing the top return spring with needlenose, or the special spring pliers found at any auto store.
[00:02:30] This spring is used to pull the brake shoes away from the drum when the brake pedal is released. Next remove the spring and pin that holds the brake shoe to the backing plate by compressing the small spring and twisting to unlock the pin holding it in place. Then remove the lower spring, and the star wheel adjuster. One side should be removed at this point, and each piece continually placed on the floor or bench in the exact position it was removed to help you reassemble.
[00:03:00] Now remove the other shoe’s spring and pin holding it to the backing plate to allow you the flexibility to remove the emergency brake cable, which can be tricky at times. The emergency brake assembly is typically attached to only one side of the brake shoe. Sometimes the front shoe, or sometimes the rear shoe, depending on the particular car. Either way, you’ll most likely need to reuse this hardware, so be extra careful when disassembling these components. We’ll come back to this shortly, but let’s take a closer look at the parts. Notice the shoe closest to the front of the vehicle
[00:03:30] is shorter in length than the shoe closest to the rear. That’s why it can be helpful to only do one brake job at a time, and always compare the old shoe with the new shoe to make sure they are the right part before you go any further. Continue to pull out all the new parts from the auto store and lay them out in order and do a quick inventory. Once all the parts have been accounted for, clean the old parts that you’ll be reusing with brake clean, including the new drum, which comes from the factory with a thin protective coating for shipping
[00:04:00] that should be removed with brake clean prior to installing. Use a wire brush to clean up the brake shoe’s contact points with the backing plate. There are typically three spots on each side. Here, here, and here. Once brushed clean, add a light dab of high temp grease to each spot. Now swap out the old parts with the new replacement parts on your bench diagram, and double-check you have all the pieces in your kit. Reinstall the old emergency brake arm on the new shoe, but be very sure it’s the proper length shoe.
[00:04:30] Keep referring back to your picture to double-check what else needs to be added to the new shoe for your particular drum brake set-up. Reinstall the emergency brake spring to the holder and secure the clip. Reattach the the e-brake cable, and slide the pin from the back side through the backing plate and the shoe, and compress and twist the spring over the pin until it catches. This spring and pin is what holds the shoe in place.
[00:05:00] Now, reinstall the star wheel adjuster, but make sure it’s clean, then lubricate it, so it moves in and out freely. The adjuster threads are showing, or in other words, have been extended due to the wear on the old shoe. However, because we’re replacing with new or thicker shoes, we have to thread back the star wheel to reset for the new shoes, and to allow the drum to fit over them without touching. Next, focus on the lower spring and top spring, then install the spring and pin like we did on the other shoe.
[00:05:30] Before we put the drum back on, quickly wire brush the hub face and add a light dab of high temp grease to ensure the drum lays flat and doesn’t wobble in the future. Afterwards, Spencer has me tap the shoes to make sure everything is connected and centered in order for the drum to sit properly. Now install the new drum and hand-tighten a few bolts to have it full seated. We’ll retorque the bolts properly when we reattach the wheel.
[00:06:00] Spin the drum to get a feel for how loose or tight the star wheel adjuster might be. At this point, it’s normal or okay to have the drum spin freely. However, a brake adjustment must be done with a screwdriver or a brake adjustment tool that fits in a small hole in the back side of the brake assembly. The goal here is to spin the star wheel until the shoe is extended enough to have the drum spin, but has a bit of drag when it’s doing it. When you’re all set, put the wheel back on and be sure to torque them to your manufacturer’s suggested foot-pounds.
[00:06:30] As I’m sure you’ve noticed by now, replacing your brake shoes and hardware is no simple task. Each brake assembly may be slightly different from the one shown here, but use this video as a reference if you choose to take on this project. If you’re uncomfortable, seek a professional mechanic. For more how-to car repair videos, visit Autoblog.com/wrenched. I’m Larry Kosilla from AmmoNYC.com. As always, thanks for watching.