Drum Brake Repair and Brake Shoe Replacement Instructions
As I walked past my wife's (Mac's) van, I noticed a puddle of fluid at the passenger's side rear wheel. I walked in the house, dirty word, dirty word, dirty word, dirty word, and asked about the van. She said that she lost the brakes as she pulled out of the parking lot at work. Luckily the school where she works is only a mile away and all back/residential roads.
How many rear-drum brake jobs have you done? I can't count the number I've done. I know two things about doing rear-drum brakes: I usually cuss a lot, and bust a few knuckles. I'm always in the middle of the job, and thinking there must be a better way. But I'm always too angry, and in too much of a hurry to stop and think about it.
For years I used a pair of slip joint pliers to try and hold the shoe retaining springs and pull them off the top mount. Then again to remove the stupid little round disk that hold the brake anchor pins in place. I guess that's the way my dad did it, so I stayed with that
I've had people tell me about the multi-purpose brake shoe tool. One day I finally broke down and bought one. I decided to try it on the next rear-drum brake job I did. Well, I must say, I could never master it. In fact, I finally dumped the multi-purpose tool and went back to my old stand-by - slip joint pliers. If any of you reading this have used the multipurpose tool with success, I applaud you.
Fortunately, ScottE, my youngest son, was already out of college for the summer and not working that day. So he and I started the brake job, and discovered the wheel cylinder had blown out. I let him do most of the work so he could learn how to do it.
The first thing you have to do is to think SAFETY! Jack the vehicle up, put it on jack stands and chock the front wheels. Don't ever use cinderblocks. This can have deadly consequences.
If you have a digital camera you'll want to take pictures as you go so you have a reference even if you have a shop manual for the vehicle.
Tip 1: I suggest that you now squirt the brake line attaching nut, the wheel cylinder mounting bolts and bleeder screw with something like PB blast. Repeat this spraying several times while you are trying to get the drum off. This will help loosen the various nuts and bolts that you will have to remove later.
Remove the brake drum. You'll need to remove the grease dust cap. I usually use a screwdriver and a hammer to get between the lip on the dust cap and the hub. Then slowly work the dust cap out of the hub. Next you'll need to remove the cotter pin holding the retaining nut in place. To remove the cotter pin,use a pair of diagonal cutters (dikes). Start by pulling the 2 bent ends down back into alignment with the rest of the cotter pin. Then grab the top (loop) of the cotter pin with the dikes and pry up against the hub. As the cotter pin comes out, you'll have to release the bite on the cotter pin, and take another bite lower on the pin. Continue until the pin comes out. Remove the nut.
Here, cleanliness is next to Godliness. Place some old newspaper under the brake drum, and have a roll of paper towels handy.
Look closely at the drum, many have two small bolts or screws that hold the drum to the hub on the assembly line. These will have to be removed. Now you can try to remove the drum. The outer bearing should come out next as you wiggle the drum up and down a little. Wrap the bearing, nut and washer in a paper towel and set it aside.
If you are lucky, the drum will pull straight off. You may have to wiggle it a little but it should pull straight off.
In some cases, the drum will not pull off, but appears to be pretty loose. What is happening is that a lip, caused by the drum wear, has formed on the outer edge of the drum and is catching on the brake shoes. You will have to retract the shoes, by turning the brake adjuster. Look on the backside of the backing plate (towards the center line of the car) you should see a small rubber plug, about 3/4" to 1" long and about 1/4" tall. Pull this plug out to reveal the access hole to the adjuster. Retracting the shoes can be a real pain because the self-adjuster wants to turn the adjuster in the direction to tighten the shoes against the drums. You will have to really play with a flat blade screwdriver or a brake adjuster bar to "unadjust" the brake shoes. As you turn the adjuster, try rotating the drum. Is it getting harder to rotate? If so, you are turning the adjuster in the wrong direction.
Another problem is that the drums can get stuck to the shoes if the car has been sitting for a long time, especially if the emergency brake has been set. If this is the case, you should know this before you removed the axle/retaining nut. If not, replace the nut. Now try to move/rock the vehicle back and forth. If it's drivable, try letting the engine do the work for you and try and drive the car forward or backward a foot or so to break the bond between the shoe and the drum.)
If you decide to beat on the drum with a hammer, be very careful! The drum can and will break very easily. Try using a block of wood against the outer rim of the drum and don't hit the drum directly.
So we (ScottE, with me watching over his shoulder) got the drum off and took several pictures of the springs and how they were attached with our digital camera. We went inside and downloaded the pictures to make sure that they showed what we needed.
(You can remove both drums, but only work on the brakes on one side. That way, in addition to the pictures, you will have the other side to look at for a reference.)
So we are ready to remove the retaining springs. Of course I get him a pair of slip joint pliers to remove the springs and shoe anchors. This is the first time I can remember sitting back, watching, not being upset, and in the middle of the job not covered in grease and brake dust. Watching him fight with the slip joint pliers and the springs, I thought there must be a better way.
It dawned on me to give him a pair of vise grips. That was a lot easier! He could concentrate on stretching the springs and not also having to squeeze the pliers to keep the pliers from slipping on the springs.
Once the springs were off, he started to tackle the infamous shoe anchors. Again he was having a heck of a time, trying to get the pliers on, squeezing them, turning them and hitting the side of the backing plate. Again a light bulb moment!
Tip 4: I went and got him a pair of needle-nose vice grips.
That worked so much easier.
So now we have the brakes shoes and most of the parts off - except the wheel cylinder. It's time to clean the backing plate and the adjuster. We used a can of the spray brake cleaner, sprayed the backing plate, then we used an old 1" paint brush to try and get the dirt and crud off. We used an old steak knife to scrap the really heavy gunk off the backing plate.
I really suggest that you replace the wheel cylinders, if they are available, anytime you replace the brake shoes. They are typically $10 to $30 each. You might also want to think about replacing the springs. The springs are in a "brake hardware kit." [Webmaster addition: definitely replace the springs. Note that Mopar now sells "value line" kits which, they say, contain all needed brake rebuild parts.]
If new cylinders aren't available you'll have to hone the old ones to clean the bore, and put new seals (from a rebuild kit) on the piston. If you are dealing with an unusual car - keep the old wheel cylinders so you can have them sleeved if, at some future date, you can't get new cylinders. If you don't replace the cylinders or rebuild them, you'll be doing the job again very soon! Why? Because dirt or junk will collect near the center of the cylinders. With the new shoes installed, the piston and seals will be forced back towards the center of the cylinder. Consequently, the seals will be working in all the dirt which will tear up the seals and cause the wheel cylinders to start leaking.
DON'T use an open end wrench to loosen the brake lines. You are supposed to use a "flare" wrench. I've had flare wrenches open and slip on me. This will bugger or round off the nuts making it harder to get them off. I prefer to use a pair of vise grips to initially break any hydraulic line loose from its seat. You may bugger a flat or two on the nuts, but you'll still be able to get an open end wrench on the nut to finish unscrewing it.
From Malcolm on Chrysler Minivan Forum: "Turning the nut will twist the brake line, causing it to break and add another fun experience to your job. Try removing the bolts from the wheel cylinder and pushing the cylinder (still attached to the brake line) off the backing plate. Then just turn the brake cylinder while holding the brake line nut still. This way the brake line is not twisted."
You will want to place a catch can under the brake line as the brake fluid will drip out of the brake line as long as there is brake fluid in the system. Also, remember that brake fluid will eat paint. So be careful of what you touch after you get brake fluid on your hands, and where the fluid is dripping. It's not too bad when it takes the paint off of the backing plate (unless it's a show car), but you don't want to touch the body and mess up the exterior paint job.
If for some reason, you have to pull the emergency brake cable from the backing plate, use a small hose clamp to compress the fingers. Then simply push them through the hole in the backing plate. Then remove the hose clamp.
Everything was ready to go back together.
We started by putting the new wheel cylinder in.
Trying to get the metal brake lines to re-connect to the wheel cylinder after the cylinder is mounted can be a real pain and you can strip either the nut or the threads in the cylinder. To help get the line aligned, hold the wheel cylinder up and screw the brake line to the cylinder before you mount the cylinder. This way, the cylinder can be moved around to get the right alignment with the brake line. Then put the cylinder in place on the backing plate and bolt it down.
I slid the nut as far back on the brake line as I could, and put a little dab of antisieze compound on the steel line. Then slid the nut forward and twisted it. Hopefully, this will help keep the nut from freezing on the line in the future.
Now we started to mount the shoes. Watching him try and hold the shoe to the backing plate and try and get the anchor pins in to hold the shoe looked like the old monkey and football routine. Usually I'm doing a brake job by myself, so I didn't want to hold the shoe for him. It finally dawned on me how he could hold the shoe to the backing plate.
Tip 10: Hold the shoe to the backing plate with a 4" C clamp.
Now he only needs 2 hands, one to hold the anchor pin against the back of the backing plate the with the spring balanced on it, and the other to hold the locking disk in the needle-nose vise grips.
Once the shoes are on, it's time to put the adjuster and springs back on. We put some antisieze compound on the threads of the adjuster, and put it in position. Then the springs were put back on using the vise grips.
You are now ready to reinstall the drum.
At this time, you should think about repacking the wheel bearings. If you haven't repacked the bearings, it might be a good idea. I usually do it every time I replace the brake shoes. If you are going to repack the bearings, you'll need a new grease seal for the inner bearing (total of 2 required - one for each side). To clean the old bearings, I take a jar, something like a peanut butter jar, and put some gasoline in it. Then set the bearings in, one at a time, and slosh it around. This will get most of the old grease out. Then I use the garden hose and water to rinse the bearings off. Now it's time to put new grease in the bearing. A lot of people pack the bearing by hand, just pushing grease into the gap between the inner and outer races. I prefer to use a bearing packing tool. These are pretty inexpensive, between $7 and $15, and available at most auto parts stores in their tool section. Simply unscrew the top, put the bearing on the lower plate, screw down the top plate, attach a grease gun to the fitting and squeeze the trigger on the grease gun until grease comes out the bottom of the bearing.
One side down, one to go. The other side went a lot smoother!
Hope this helps.