Hooniverse 101- Let’s Do Drum Brakes (Part Two)


Hooniverse 101 is intended as an introduction to auto maintenance and function, so as to give inexperienced car owners a leg up on either tackling simple maintenance tasks themselves, or being better informed when going to a shop, potentially helping to not get ripped off. Today, in part 2, we are wrapping up our discussion on the function and maintenance of the drum brake.

Out With The Old, In With The New

When we last left our poor Datsun 240Z, it was up in the air with its shoes pulled off. Now that we’ve completed our inspection of the wheel cylinder and bearing surfaces, we’re going to start reassembling the brakes, and will  be replacing a number of parts.

If everything looks good then it is now time to lube up and dive in with the new shoes. In the case of the Datsun, you’re expected to put a little high-temp grease on the supporting blocks on the backing plate (there are three on each side, looking like little dashes) as well as on the pivot points.

Once that is done you’ll need to decide which spring goes where in re-assembly and this is where pictures and the properly assembled other side become invaluable. In my case, the black spring with the s-shaped ends proved to be the one that is impossible to install with the shoes in place so I slotted that in while they were off the car. The spring and shoes combo then gets put in place, with the bottom of the shoe correctly slotted into either side of the wheel cylinder.


Now it gets tricky and this is where an extra set of hands becomes valuable, but not required. First, slide the anti rattle pins in through the back of the backing plate and through the aligning holes in the middle of the shoes. Assemble the rear seat, spring, and front cap and slide it over the pin ensuring the flat slots through the front cap.

Next, hold both shoes in place and, using your long nose pliers, grab the flat of the pin while you push down on the cap with your thumb and forefinger. Twist the pin to seat it in the cap. The second shoe will prove much easier.

Now comes the really hard part so put on your muscles and get ready to use them. The remaining spring now needs to be stretched in place. I do this with the brake shoes off their pivot block perches, just to allow a little more ease. I first slot the spring into one shoe and then, using the hook (Arrr!) of my brake tool, pull the spring to the lip of the hole on the other shoe and then seat it with the end of my mallet handle. Then I use my channel locks to pull the shoes into their perches on the pivot block.

Now you’re done with the hard stuff. . . for this side at least. Check your work, making sure everything is in its respective slots both top and bottom, and that the anti rattle pins are seated fully 90-degrees in their cups.

Slide the drum back in place and give it a spin to ensure that there are no areas binding, but don’t put the wheel on just yet.


Let It Bleed

If you haven’t opened up the hydraulic system any then there’s little need to bleed your brakes after changing the shoes, but it never hurts to go in and give the system a good burp any time you’ve messed with the brakes.

The purpose of bleeding the brakes is to remove air from the system. Hydraulic fluid doesn’t compress, air does. Air in your hydraulic lines means that when you press the pedal, the air gets compressed rather than the brakes and you won’t stop. You’ll also want to bleed them out in the event you want to change the fluid en toto.

To bleed your brakes you need to follow a pattern which is to start the farthest away from the Master Cylinder working your way to the wheel that’s closest. There are a couple of ways to do it, one requiring a vacuum pump which allows you to undertake the task solo, should you be the Earth’s last inhabitant or an angry loaner. The other is to enlist a friend, family member,  or street person promised a can of beer to push down the brake pedal while you selectively open and close each brake’s bleeder.

Whether you choose to go the introspective vacuum approach or the pump and dump, one thing’s for certain, you will need a flare wrench. This is an open-ended wrench that has an extra pair of flats over a standard wrench, and which will prevent the fragile bleeder from getting rounded over, which would be a bad thing,


In my case, all the bleeders are 10 MM. Let’s go ahead and walk through the friendlier method. Your goal is to remove any air from the brake lines, and to do that we want to pressurize them, just like applying the brakes.

First pop the cap off of your Master Cylinder – it’s that reservoir that’s likely ahead of your steering wheel and perhaps even markets as BRAKES. Look at the side of the reservoir, there’s likely a pair of lines marked on there, which are minimum and maximum fluid level. Top up the reservoir with your car’s required brake fluid.

Now enlist a friend to sit in the car and roll down the window so you can hear one another. You’ll need to reach under the car (again make sure it’s securely supported before sticking your mellon under there) and place your flare wrench at the farthest point on the bleeder nut (it looks like a hex nut with a nipple on it) allowing a counter clockwise arc.


Once the wrench is in place, attach a length of hose – I told you that you would need a length of hose, right? – well you will. Attach one end of the hose to the nipple on the end of the bleeder nut, and the other end submerged in a jar with about an inch of brake fluid in the bottom.

Ask your friend to pump the brake pedal one-two-three times, and then to hold it down. Once they are pushing steadily down on the pedal, turn open the bleeder valve. You will hear a sputter of air and see bubbles in the jar fluid, as the air is pushed out by the pressure from the pedal. Meanwhile the brake pedal should fall to the floor under your friend’s foot. You’ll need to repeat this a couple of times until no more air comes out, and then on each of the three remaining axles.

Once you’ve done all that, it’s time to take the car for a test drive, but be very careful here as the brakes may need some pumps to fully seat the new shoes and ensure everything is working okay. Remount the wheels hand tightening the lug nuts and then drop the car off the jackstands. Torque the lugs to specs once the weight of the vehicle is on them to prevent spinning. Now you are ready get in and start it up.

Don’t however go anywhere just yet. First pump the brake pedal and make sure that it feels solid and doesn’t have an excess of travel. Next apply the hand brake and see if it is functioning as expected. If it exhibits too much travel then it will need to be adjusted, which will require a visit to your service manual to determine the details of just exactly how to do so. It will likely self-adjust as you back the car up and apply the brakes.

Now, slowly move the car and, ensuring that it is safe to do so, apply the brakes. Listen for any weird grinding or hissing noises. Once you are sure that the brakes are properly seated and working as they should, go ahead and repeat the last action at a slightly higher speed. Note if there is any feeling of grabbing or pulling.

If everything feels good, head back to your work area and stop the car. Get out and do a visual inspection of your work. Are there any signs of fluid leaks? Recheck all your lug nuts and if you need to adjust your hand brake cable this would be a good time to do that.

If everything checks out in both your visual and driving test, then you have successfully changed your brake drums, and can check that skill off your bucket list. Being able to undertake these basic auto maintenance tasks will not only fill you with a sense of accomplishment and earn you bragging rights at the Sports Bar, but they’ll also let you save a load of money over having a shop do the work. If you are more experienced and have additional tips to share, please feel free to do so below.

Images: ©2013 Hooniverse/Robert Emslie

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39 responses to “Hooniverse 101- Let’s Do Drum Brakes (Part Two)”

  1. dukeisduke Avatar

    What kind of vehicle is this, Robert? It looks like it has semi-trailing arm rear suspension.

    1. Robert Emslie Avatar
      Robert Emslie

      That's my 1971 Datsun 240Z

  2. dukeisduke Avatar

    Also, be careful about breathing in brake dust. Modern brakes don't use asbestos anymore, but you still don't want to breathe in a lot of dust. A friend's dad was an auto mechanic for a many years, and did a lot of brake work. He died from mesothelioma, most likely from all that asbestos dust.
    He did tell me something about doing brake work in the old days. If a car came in with a leaky wheel cylinder, but the shoes were still good, they would take the shoes off and throw them in a fire (What kind of fire? I don't know), to boil out the brake fluid, and then put them back on.

    1. krazykarguy Avatar

      At the shop I worked at, contaminated brake shoes were ALWAYS replaced. Oil, grease, brake fluid, it didn't matter.
      If your brakes stop working as a result of your mechanic's decision to re-use contaminated parts, and your brakes fail, I can't think of a bigger justification to sue for negligence. When working on a system as critical as the brake system, you don't cut corners.
      Over what? A $30 set of brake shoes? Not worth it.

      1. dukeisduke Avatar

        Well, we're not talking about today, we're talking about the 1950s and 1960s. It was a different era. I knew one guy who was a Chevrolet mechanic then, and they weren't allowed to do things like simply remove generators, starters, a/c compressors, etc., and replace with new. They were expected to tear down parts like that, repair them, and reinstall them.

        1. krazykarguy Avatar

          While I appreciate your story for how things used to be in the '50s and '60s, it's 2013.
          Tossing contaminated brake shoes into a fire to 'boil off the brake fluid', while awesome on a bunch of different levels, doesn't fly in today's world of auto repairs. While it may work to 'save' the parts for re-use, I wouldn't even attempt it when a brand new set of shoes is so incredibly inexpensive.

          1. dukeisduke Avatar

            I'd never do it today, especially with bonded shoes, because you couldn't be sure if the lining would stay on.

          2. mdharrell Avatar

            Automotively speaking, it's only 2013 for some of us.

          3. Tony Smith Avatar

            aahh.. but, you gotta love this traditional beast in some way other. BTW, this is my opinion. 🙂 http://www.avac.com/vacuum-chambers.php

    2. toxonix Avatar

      Was he a mechanic in Karzikistan? Brake fluid is just another type of hydraulic fluid, and is flammable. Those brakes would burn out the brake fluid, and whatever binder that holds the shoes together. This kind of thing sounds like something he picked up while in a Central African republic.

  3. frankthecat Avatar

    Another protip:
    Before you put the shoes back on, lift up the boots on the ends of the wheel cylinders. If you see any fluid weeping, go get yourself a new set and replace them all. Brake fluid + drum = not much braking power, so fix it before they fail completely.

  4. muthalovin Avatar

    Unrelated: after I ran my first half-marathon, I had bleeder nipples.

    1. dukeisduke Avatar


    2. calzonegolem Avatar

      From the friction of your shirt? Or did you just squeeze them too hard in excitement?

      1. muthalovin Avatar

        Why not both?

        1. ˏ♂ˊ mzs zsm msz esq Avatar
          ˏ♂ˊ mzs zsm msz esq

          Also you should lube them next time, get a nipple fitting for your gun, and squeeze until some oozes or spurts out.

          1. muthalovin Avatar

            TMI dude. T. M. I.

  5. Alff Avatar

    Performing a lot of adjustment on the star wheel through the little slot on the backing plate can be tedious. I like to do a rough adjustment from the front with the drum off, even to the point of overspreading them so the drum doesn't fit and then backing off.

    1. Van_Sarockin Avatar

      There's always measuring internal drum diameter, then adjusting the shoes to be a little smaller…

  6. ReneM Avatar

    I've tried the hand pump vacuum and it never really worked for me. Not enought patience maybe? Probably also to do with the amount of volume a car brake system has, and being able to keep the vacuum from the vacuum pump to the master cylinder. It is quite easy to lose the vacuum at the bleeder valve and have nothing happen.
    Anyway, If you have the funds, are an angry loaner, just like tools, or do a lot of brake bleeding I'd recommend something like the Mityvac 6830.

  7. FЯeeMan Avatar

    WARNING: Threadjack!!
    Anyone know what's involved in replacing the alternator on a B5.5 VW Passat? A quick perusal of VWVortex looks like it's nearly $1000, mostly labor, at a dealership… 🙁

    1. FuzzyPlushroom Avatar

      How is that even possible? It's a six-pack job on a D-engine Civic, and only then because the power steering pump's in the way.
      [youtube xS_5axvU1s8 http://www.youtube.com/watch?v=xS_5axvU1s8 youtube]

      1. FЯeeMan Avatar

        And… that's why the stealership will charge you wads of cash.
        Fortunately , I've got the 1.8 turbo 4.
        Disconnect the air intake (one hose clamp, one little springy clip)
        Remove the fan. One bolt
        Remove the alternator. 2 bolts
        Remove the negative & the controller? wire. 1 bolt, 1 clip
        Took more time than it should have, but then I was feeling my way along and learning. Probably about 3.5 hours work time plus a trip to the parts store for the replacement.
        Worked with my youngest son. We had fun.

  8. Kris_01 Avatar

    So far no one's talked about gravity bleeding. You can actually bleed the brakes using nothing more than gravity to push the air out.
    Basically, the premise here is that the master cylinder is located on a higher plane than the rest of the braking system. If you crack a bleeder nipple, the weight of the fluid in the master cylinder reservoir will cause the fluid to move in the open line, resulting in air bubbles eventually being pushed out.
    I wouldn't do this if I installed something like one new wheel cylinder, for example. In actual practice, I use this process when I install a complete set of new brake lines on a vehicle (being in Eastern Canada, lines rot out with depressing regularity). It's time consuming, and you have to keep an eye on the fluid level in the reservoir, but it makes for an easy way to fill all the lines without your helper's foot getting cramped from all that pedal pumping.

  9. Van_Sarockin Avatar

    Nice write up. I wish you'd told us how to find the spring or circling that flies away to the darkest, inaccessible grubby corner of your garage.
    If you can, bleeding the brakes is an excellent task whenever you do other brake maintenance. Brake fluid doesn't last forever, and it can get sludgy with debris and contaminants-especially near the wheel cylinders- and it picks up water as well as stray air bubbles. All of that is bad for your brakes, and for braking performance. Having a friend helping to pump the brake pedal is ideal, but there are a number of vacuum and pressurized pump systems available to ease the bleeding. Pro Tip: overfill your master cylinder reservoir before bleeding, and check its level frequently. If you bleed so much fluid that the reservoir is emptied, you'll introduce new air in the lines, negating all your prior bleeding effort.

    1. krazykarguy Avatar

      The biggest issue with brake fluid is that it's hygroscopic, meaning that it absorbs water.
      Water + steel brake hard lines = potential for failure. It also decreases the boiling point of the brake fluid, which can lead to brake fade with repeated hard stops.
      Always a good idea to flush your brake fluid every 30k or so.

      1. needthatcar Avatar

        Oh yeah, I always flush out my brake fluid. That stuff's always going bad. I usually replace a fender or two every 6 or 7k miles too. You know, they start to break down. Shocks? Every oil change.
        Seriously though, if the brake system is working properly, and there are no leaks, there will be no water in the system. Condensation? Maybe, but so minimal – that's why they put that little expanding rubber boot on the underside of the master cylinder cap, to keep air out of the system. I totally disagree with the idea of flushing brake fluid inside of anything less than 10 years. The likelihood of screwing something up or causing a leak by opening up the system is, in my opinion, much greater than the likelihood of a failure due to old brake fluid.

        1. cheapthrills Avatar

          I used to have the same opinion: it's a sealed system, so why change anything?
          As someone whose family has had brake lines rot out on 5 occasions, I fully disagree with your assessment. Brake fluid is often visibly contaminated within 2-3 years on older cars. Flushing it adds ~20 minutes and $15 onto a brake job. Removing the nasty brown gunk will greatly reduce your chances of having a failure. Fully flush your brake fluid (i.e. empty out the master and get clear stuff to every wheel and clutch) every 2-3 years or at every brake job.

          1. HTWHLS Avatar

            I agree that I used to have the same opinion, well..also a little more "if it ain't broke, don't fix it" mentality. But then someone straightened me out. Dipping a clean cloth in the master cylinder, the fluid looks clean; run a finger along the inside of the master cylinder and "yuck" will be on your finger.
            I'm a dedicated convert to flushing the entire system every 2 years/25K miles, whether or not the pads/shoes need changing. Now, if only someone here can tell me where to safely get rid of this dirty brake fluid…THAT would help!

        2. krazykarguy Avatar

          The likelihood of 'screwing something up or causing a leak' is because you waited 10 years to open up the system and bleed it. Leaving it be that long is asking for a brake line R&R, especially in the salt belt or humid climates. Not to mention that any moisture in the lines will corrode the steel from the inside out.
          I can't think of a single car/manufacturer in recent history that doesn't recommend a brake fluid flush at a set interval.
          The moment that the brake fluid is introduced to the system, it immediately begins to absorb water. It's from the air, not condensation. It's NOT a completely sealed off system – water enters through pores in the dozen or so rubber seals and hoses in the system. In addition, rubber seals wear out, especially with brake fluid – which is nasty stuff. The next time you get it on your skin, take note of how extremely dry that area gets even after you wash it – the brake fluid has literally sucked the moisture out of your skin.
          Try reading this, and maybe you'll change your mind: http://www.aa1car.com/library/bfluid.htm

          1. prismatist Avatar

            Any time I do brake work, I bleed the system for whichever wheels I am working on. And when I bleed, I always use up one entire container of brake fluid since the stuff does not keep once opened. Another good reason to bleed them any time you open up the system is to keep the bleeders from seizing.

        3. C³-Cool Cadillac Cat Avatar
          C³-Cool Cadillac Cat

          Damn. It.
          Accidentally voted 'up'.
          Every year, I'll suck out all the fluid in the reservoir, making note of the level, beforehand.
          Refilling with fresh mixes enough with that in the lines it appears to keep the entire system pretty funk-free.

  10. Alff Avatar

    I built a pressure bleeder (pushes fluid downstream from the reservior) from an inexpensive garden sprayer, a spare reservoir cap and a couple of hydraulic fittings. Total cost – $20. Works like a champ. Just don't over pressurize.

  11. danleym Avatar

    I always replace the springs and such. It sounded like you reused yours, which isn't necessarily wrong, but I don't know how to look at a spring and tell if it has lost it's spring rate. A hardware kit is $5, maybe $10. If I'm in there, I'm going to spend the 5 or 10 bucks so that I don't have to do it again any sooner.
    And yeah, the always pump your brakes before putting the vehicle in gear is good advice. I was helping a friend change his brakes once, and as soon as I put the car in reverse once we were done it started taking off, despite my foot being on the brake. In a half second I realized what I had done and I started pumping the brakes very quickly. Fortunately I got enough pressure built up to stop before I hit anything.

    1. cheapthrills Avatar

      What I've learned regarding drum hardware: the rusty OEM stuff lasts longer than fresh cheapo stuff. I replaced all mine with the $10 set from the discount auto parts store, and they rusted and snapped within a year. YMMV

  12. Bob W Avatar
    Bob W

    how did I ever managed to survive into my adult life without knowing about flared wrench?
    No wonder I keep stripping the bleed nipple on my motorcycles. And I had put that down to my impatience when working…

  13. jaseman Avatar

    Just an FYI on the rubber hose…
    Instead of finding a section of scrap of old fuel line (or other black tubing) save those old vent hoses from motorcycle/lawn tractor/utility batteries. Not only are they the right diameter for most bleeders, but they're clear! Helps you see the air coming from the lines, well before it ever makes it to the jar. Actually saves a good bit if fluid, as you're spotting air much sooner.
    Any clear tube will work. I just happen to have a lot of 'toys' that use the old vented MC batteries!

  14. Otto Nobetter Avatar
    Otto Nobetter

    Maybe I missed this part, but when your Friend pushes the pedal to the floor, make sure he holds it there until you close the nipple…otherwise you're sucking air back into the line if he lets up on the pedal and the nipple is open..
    Harbor Freight sells an air-operated brake bleeder if you want to (or have to) do the job yourself. As the Primer states, just be sure to keep the reservoir topped off as the power bleeders can use fluid at a quick clip. And for the nipple, a box-end wrench(or a 6-point socket) works fine-no need to invest in a Flare Wrench except for brake lines/clutch lines/fuel lines, etc

  15. HTWHLS Avatar

    I had (can't find it right now) a bottle that kept the m/c fed while you were using a Mityvac or one of those venturi-effect (air-powered) bleeders. Worth it's weight and it made the brake job a true one-man job.
    One other add on: get the gauge and check the drum in multiple places. Even if's good, have it "cleaned up" (lightly turned) anyway to ensure its clean, and round. If you're in this deep, just do it.
    Now, does anyone know of a chain store you'd trust to turn drums or cut rotors? That's getting damn near impossible around here these days.

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