Drum brakes

I just did some work on my rear brakes, and I'm very happy with the results, but it was a lot of work.

Firstly, I want to recommend that you all service your rear brakes much more frequently than just when you need to replace your shoes. Drum brakes go out of adjustment after a while, in spite of the automatic adjusters, and the grease in the brakes will dry up faster than the shoes wear out.

The differences to me are phenomenal. My brakes were a bit loose. I could tell because the parking brake uses the rear brakes, but mechanically instead of through the hydraulics. This makes the adjustment issue evident because my brake pedal was a little soft, but it would firm up if I had the parking brake on a couple of clicks. In essence, the brakes would be firmer when the rear brakes started off being partially engaged, but not enough to make the brakes drag.

The second difference it makes is that with fresh grease installed, there is less friction fighting you from within the brake, so the same effort at the pedal produces more braking force.

Between the two differences, my brake pedal feels the same at first, but the brakes engage more quickly as I press the pedal down, and I get much more braking force with the same effort! I am very glad I did it, but it was a lot of work, and I learned a few things from it that I didn't know from working on previous drum brakes I've serviced.

Most of my difficulties were from the upper shoe return spring. Those of you who have worked on drum brakes will be thinking 'duh!' but bear with me.

The return spring on these brakes was both stronger than on previous brakes have worked on (like almost twice as strong as the Toyota I used to drive), and positioned in a much less convenient way.

On other drum brakes I've worked on, the mechanical adjuster is usually positioned next to the return spring. On the CRV it is positioned inside the return spring. That makes it much more difficult to reinstall the two because they fight with each other over position. Luckily, the mechanical adjuster has a groove in the outer side of end towards back, which helps with reinstalling the two together.

The first thing I will say is whenever you take the adjuster out, always, always, always clean and completely regrease the mechanical adjuster. This is something that needs lubrication in order to work on its own without mechanic intervention.

Unfortunately, there was no specific procedure in the service manual for reinstalling everything, however I found it it worked best like this:

Completely remove the parking brake lever adjustment before reinstalling shoes. The parking brake lever adjustment will throw off your other adjustments.

Also, make sure you clean and put fresh brake grease on all of the shoe contact points on the shoe guides, wheel cylinder and backing plate, before installing the shoes.

Install the rear trailing shoe first with the parking brake lever completely installed and setup. (The parking brake lever that is attached to the shoe, not the one on the floor of the car next to the driver seat.)

Next you will need to make sure that the mechanical adjuster is assembled inside of the return spring. The parts that screw together have to be screwed together while they're inside the return spring, or you won't be able to put them inside. The longer end of the return spring needs to point toward the front of the car, and it needs to hook onto the leading shoe from the inner side, toward the center of the car. the ratcheting gear screw also needs to be toward the front of the car, with the tube that it screws into toward the back of the car.

The next thing to do is to hook the lower return spring on to the trailing shoe that's already installed in a car, and leave it hanging.

After that is where things get complicated. The upper return spring, mechanical adjuster, and leading brake shoe have to be manipulated as a single unit. the reason is because the ends of the return spring wrap around the adjuster; they will try to occupy the same space as the ends of the adjuster, and prevent you from hooking the ends of the adjuster into the shoes where they need to be.

Hook the leading end of the upper return spring to the leading shoe from the inward side, toward the center of the car. The trailing end of the adjuster has a groove in it. That groove has to be on the outside where you can see it. After the return spring is hooked into the brake shoe, and the leading edge of the adjustment mechanism is also hooked into the leading brake shoe, you need to pull the trailing end of the spring to the side and hook it into that groove on the side of the adjuster.

The end of the spring and the end of the adjuster need to stay completely flat with each other, or they will fold up, and the spring will prevent you from hooking the end of the adjuster in to the trailing shoe.

After that gently push the adjuster into its slot in the shoe, while sliding the return spring away from the shoe as far as you can, keeping the end of the spring set into that groove. The friction between the adjuster and the spring when it is being pulled like that will help to prevent the spring from unhooking from the leading shoe.

Then hook the bottom of the leading shoe into the lower return spring, and swing the shoe, upper return spring and adjuster up as a unit. While swinging it up, the first thing to do is to carefully fit the adjuster and return spring between the wheel hub backing plate and wheel cylinder.

Again, the return spring and the end of the adjuster need to stay completely flat so that they are hooked into each other and cannot fold up on you.

As you fit the return spring and adjuster through the brake, make sure that the lower end of the brake shoe gets hooked into the correct position of the cradle at the bottom that holds both shoes.

After that, fit the top edge of the shoe into the slot in the wheel cylinder piston, as you fit the trailing end of the adjuster sort of into the slot in the trailing shoe. I say sort of, because if you completely shorten the adjuster, it won't be quite long enough to reach, with the wheel cylinder separating the two shoes.

Then comes the trickiest part. To protect the wheel cylinder from being damaged, gently hold the return spring and adjuster so they do not fold up and interfere with each other, while extending the adjuster by unscrewing the racheting gear until the adjuster makes contact with both shoes.

To prevent the leading shoe from just pushing the trailing shoe right out, by way of pushing on the wheel cylinder, I put a clamp on a backing plate to stop the trailing shoe from moving away from the wheel cylinder. With that clamp there, I used a pair of vice grips to grab the upper return spring, stretch it out and hook it into the trailing shoe.

I am told there is a pair of pliers just for installing the upper return spring, but I have never seen one and have used vice grips every time I have assembled drum brakes. I really don't think it's possible to assemble a drum brake without using a pair of vice grips or otherwise very strong locking pliers to stretch out that spring.

That last bit was the most difficult part. After that everything was pretty much easy.

The next thing to do is to adjust the adjuster so that it was as tight as you can get it, while allowing you to turn the drum freely back and forth with your hands after you put the drum on.

I also found it easier to make the adjustment to the drum if I left the automatic adjusting arm out of the brake until after I made my adjustments. After making my adjustments I then put in the automatic adjusting arm and the adjusting spring.

After adjusting both brakes, and reinstalling both wheels, you can readjust the parking brake. I found it surprisingly easy to adjust the parking brake. I pretty much tightened the adjusting nut with my fingers until it was just tight enough I that would have needed a wrench to go father, and that actually made the parking brake exactly as tight as it is supposed to be. The specification in the manual is that it should take about 44 pounds of force to lift to the parking brake lever six clicks.

I figured I ought to spell out the procedure I used because I was not able to fit together any other way, and it would have been a lot less frustrating if I had had a step-by-step like this before I started.

I tried to fit my left rear brake together at least a dozen times before I figured this procedure out. After I had the left brake together, the right brake took me all of 20 minutes from start to finish.

Hopefully this helps you guys to do brake work with less time and aggravation spent. I really do like the results that it gave me, with pretty much just lubricating and readjusting the rear brakes. It actually makes a big difference when you're not wasting fluid pressure just by pushing the shoes out into the drum, and when the rear brakes are doing their fair share of the work.