-In trying to fit the springs and mount the new shoes, the piston of the wheel cylinder moved back and forth a lot, I may have over-compressed and/or overextended the pistons. Unlike calipers, they seem to just “slosh” around with no resistance. This concerns me but there is no evidence of leakage but I wonder if this is normal.
This design features two return springs, an inner and an outer (see pic.) I forgot to install the inner springs, but the outer springs are so strong it was very hard to put in place, really struggled with this. I’m going leave out the inner return springs and just see if this works OK. Remember, with drum brakes UNEVEN wear is NORMAL----the design is so inelegant and imprecise that I’m betting this won’t be a problem.
The brakes are now spongy but if you pump the brakes it becomes firm again, then becomes spongy again at the next brake application. A Google search reveals that this is because the adjuster wheel wasn’t adjusted, which is true, I did not adjust the star wheel. I will do so tomorrow.
I replaced the rear shoes on my Corolla not too long ago. There’s a couple of tricks which make the job quite a bit easier. One problem I recallI had was getting the parking brake cable re-attached. When I learned the trick, it was a piece of cake. Unfortunately I no longer remember the trick. I think it involved using one of those surgeon’s locking pliers gadget. But it doesn’t matter if I recall or not, b/c there’s plenty of u-tube vdo’s on this exact topic. That’s how I learned easier ways to do it. Just takes 15-20 minutes of watching them is all. Just do one side at a time is all, so you have the other for reference.
A lot of it is the order you attach things. That’s important for the springs for example. If you do it in the wrong order it can be a bear. Ask me how I know … lol …
I had some frustrations keeping the wheel cylinder’s “ears” aligned and staying where they should too. They do have a tendency as you say to move in and out as you fiddle w/other stuff. But no harm came to the wheel cylinders in the process. You just want to make sure the little slots in the “ears” are lined up with the tabs on the shoes when the job is complete is all.
Be sure to pull the rubber boots back for a look-see. If there’s a lot of brake fluid in there good idea to replace the wheel cylinder.
Suggest you look at some u-tube vdos to learn the tricks and tools used to make the job easier, then disassemble it all to the point just the shoes are held on by the spring clips. Then re-assemble the whole she-bang properly, including all the springs. Then adjust the shoe adjusters so you can just barely install the drum over the shoes. You can tighten the adjuster up further once the drum is on by pulling on the parking brake handle a few times. I think you’ll discover this won’t take you nearly as much time now you’ve got the basic idea and learned the best order and the special tools you need to attach the stuff.
This is the style of the surgeon’s locking pliers I’m talking about. You need the basic drum-brake tools also, which I presume you already have. I think most diy’ers doing drum brakes for the first time remove and re-install everything 2 or 3 times minimum before they get it to the point where the job is pretty easy and is done correctly.
Drum brakes are old tech, proven, but a PITA for someone unfamiliar with them.
Put in all the original springs, they were there for a reason and you don’t want to find out why “by accident”. Check out a Utube video for the reassembly order and life will be a lot easier.
“Spongy” often means air in the lines so while you’re in there, do a complete brake bleed. Cheap and easy to do (some brake fluid, a wrench, some vinyl tubing and a friend for half an hour to pump the brakes). Again, check out Utube for how to do it and look for any leaks while you’re doing it.
Unlike Disk brakes, Drum brakes are generally self activating and not self adjusting, which means that they require their initial contact on the drum to power them. I’ve seen adjusters so far out of whack that the pads didn’t make contact with the drums at all or the new pads were in constant contact (Lord knows how they managed to get the drum back on)
Generally you start the job by backing off the adjuster to get the drum off and end the job by tightening them up until the wheel won’t spin and then backing off until it spins freely. Again, see Utube.
Finally and VERY IMPORTANT, always wear safety glasses when messing about with the springs!
I’ve had them spring off like a shot and it can be very sobering.
Brakes are a safety issue so either look up how to do it, take your time, do it right and don’t cut corners or take it to a mechanic.
I will get a specialty tool for next time, turns out Harbor Freight has a set of 3 tools for a mere 13 dollars. It’s well worth it.
My reasoning for leaving the outer springs:
It’s a low-risk experiment. I can always redo the job with a new set of drums and shoes ( a mere 50 dollars total at RockAuto.) I pondered the risk—the shoes don’t return as quickly which means there is a risk of it dragging momentarily against the drums, causing perhaps uneven wear. Since the drums do so little of the braking, there is very little chance that it causes the car to steer in an unexpected direction should it someone lock against the drum (impossible really.)
I want to see how much tolerance is built into the design. I think there’s a lot.
An inelegant design:
-The contact points of the shoes has to rub against the backing plate when it operates. There is a lot of resistance in the parts rubbing against each other. a LOT of rubbing even with a generaous application of brake grease.
…and next time hire someone to do your drum brakes if you’re not up to doing it right. There is no shame in farming out work you don’t want to do, particularly if you can’t change the shoes without sliding out the brake pistons and having to worry about air getting in the system or damaging them to where they might leak.
That might be why they feel spongy, because air got in the pistons when they slid out, so you’re going to need to bleed your brakes.
Yes, drum brakes take more work and effort than disc brakes, but since most of the braking is done in the front, you shouldn’t have to do the job more than 2-3 times during the time you own the car.
Exactly. It’s not that you’re truly interested in conducting an experiment, it’s that you don’t want to re-do the job and are justifying it through some sort of empirical endeavor. Ask a question, get an answer…though maybe not the one you want
Suck it up and do the job over, and do it right. It may seem like a low-risk experiment, but if the drum brakes were so inconsequential, automakers wouldn’t even have brakes on the rear wheels in the first place. Yeah, they do less work than the front brakes, but it’s some amount greater than zero, which could mean the different between hitting a child who wanders out into the street vs. stopping inches in front of them.
Besides, don’t underestimate Murphy’s law…I can think of about ten “freak” scenarios where a slow-returning brake shoe could jam in the drum and do damage to your car, yourself, or others…
I’ve seen mechanics that prefer doing drum brakes. There’s less cleaning and less lubing. After they’ve done several dozen, they can change these things out extremely quickly and do a great job. It’s amazing to watch an experienced professional do it.
Without going into too much detail, those who warned about this were RIGHT on. I ended up blowing the wheel cylinder, with brake fluid leaking out. The spongy brake pedal was mostly caused by this, as stated earlier----rather than lack of adjustment because the drums were on tight. But I did something stupid to cause this latest mess (tried to turn the car around without installing the drums back on, causing the wheel cylinder to blow) real dumbbbbbbbbbb
Good lesson learned, that’s the upside.
No one was injured but I got brake fluid on the ground which is very messy and ugly.
You aren’t the first person to step on the brake pedal after removing the drum … ask me how I know
Years ago an auto-shop instructor showed me how to replace the shoes on my truck. He told me to remove the drum then he’d show me. He removed all the parts from the backing plate then put it all back on in less than 5 minutes. His “trick” was to assemble both shoes w/the springs while everything was still laying on the garage floor. Then he positioned everything onto the backing plate as a single unit. In other words the last thing he did was attach the spring clips to hold the shoes to the backing plate. This is a bit of a magic act, a juggling act, something I wasn’t able to do with any consistency. When I tried it most of the parts would drop off and land on the floor before I could get the spring clips on. But I think if you want to be a drum brake speed demon mechanic that’s the way it’s done.
I found the link below to be an interesting thread about drum brakes. Won’t be of much value for the OP’s practical problem, but maybe still interesting.
@COROLLAGUY1 … just curioius, what’s that “Sealey” cylindrical shaped tool used for?