Braking Point: The Ancient Art Of Rebuilding Drum Brakes Part 1

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Drum brakes – remember them?  A few decades ago, they were the norm rather than the exception. And even when disc brakes made their debut, 99% of those cars had drums on the rear axle. Plenty had drums all the way around too.  Certainly drum brakes weren’t (aren’t) perfect.  Drums can fade. Drums are affected (adversely) by water. Plenty of them mandate periodic adjustment.  The reality is, disc brakes are definitely superior when it comes to stopping power.   They’re simpler too.  For example, a typical set of drum brakes can have dozens of individual parts.  And you have to deal with all them (correctly) in order for the brakes to function properly. 

Fair enough.  Swapping over to a complete set of disc brakes can be pretty easy  (there are all sorts of options out there), but if your car is original and you want to keep it that way, there are some alternatives.  You can purchase backing plates that are already “loaded”. But on the other hand, assembling a set of drum brakes really isn’t all that difficult. Honestly, there are quite a few parts involved and you’ll need a couple of special tools too but both the tools and the parts inexpensive and easy to source.  Once the drums have been turned (by a brake shop, and where necessary) the task at hand really isn’t exactly difficult. The parts aren’t hard to find either.  Your local jobber or online auto parts store most likely has everything you need in stock.  For a closer look at how it’s done, check out the accompanying slide show (Part 1 – in a couple of weeks, Part 2 will follow):

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Clearly, tools are important when performing a brake job. This is the bare basics – a set of brake pliers (on the right) and a brake shoe spring retainer tool (the one with the red handle.). You’ll also need a small packet of synthetic brake grease along with a can of brake cleaner (not shown).

Another option is this all-inclusive OTC drum brake tool set I have. It covers all of the bases, but for my purposes, it’s really no better than the pair of tools shown previously.

The place to start is with a set of undamaged, clean backing plates. Or you can buy new backing plates such as these.

Here, the anchors were removed from the original backing plates. I usually get them silver cad plated or powder coated. GM has a torque spec of 140 foot-pounds for the anchor nuts (yes, that’s a bunch).

This is a look at the collection of little parts you’ll need in order to assemble (and completely rebuild) one rear drum brake. Most of these pieces are available from Summit Racing. Depending upon kit you purchase, you might have to reuse some of your original park brake hardware.

The place to begin is with the wheel cylinder(s). They’re installed as shown here. They can only go in one way. During assembly, it’s a good idea to lightly lube the pushrods (they’re definitely subject to corrosion).

Drum brake parts are typically “sided” left and right. It’s easy to figure out: The opening for the e-brake cable faces forward.

Note the shoes are different. The brake shoe on the right is longer than the one on the left. The RH or longer shoe is the trailing shoe. The leading shoe is shorter.

Before going any further, you should lubricate the backing plates. Note the raised, dimpled surface? That’s where the lube goes. Carefully apply a small amount to each lubrication point. The lube must not come in contact with the brake shoe surface (if it does, clean it with brake cleaner). The idea is to provide lube for the sides of the shoes.

The park brake lever fits into the trailing (longer) shoe. It slips in from behind, and in most cases, it must be assembled before the shoe is assembled onto the backing place (although we’re skipping the cable for this series of photos).

The adjuster is installed next. But before proceeding, lightly lubricate the threads. On used brakes, it’s not uncommon to come across adjusters that are seized, simply because they were never lubed.

Now you can install the adjuster. The adjuster “wheel: is closest to the park brake lever. Each (side) backing plate is different.

Both the leading and trailing shoes are held in place by a coil spring perched over a “nail”. In a typical GM application as shown here, the leading shoe incorporates a beehive style of spring.

The installation tool (an OTC tool is shown here) is used to compress the spring while you hold the nail in place (it passes through the back end of the backing plate). Twisting the tool allows the nail to seat in the spring retainer. You’ll note the retainer has two recesses that lock the nail in place.