replacing rear drum brake calipers and shoes

I hate doing drum brakes, say a full shoe replacement. It's like taking apart a watch, and the springs are tough and tricky. With the right tools it goes easy, I've been told... Maybe in another life I'd get the hang of it. I did it once, on a Honda, with the wrong tools: swore I'd just let the pros do it next time.

The most I'll do is take the drum off, remove the clips that tension the shoes, holding them against the backing plate, lube the contact points with backing plate (typically 3 per shoe), carefully, you don't want to lube the shoes. Then put everything back together, done.

For getting the drum off, there's usual a pair of threaded holes: if the drum is refusing to come off, you screw bolts into the holes, back and forth, until the drum is pushed off the shoes. Bolt size is M8x1.25.

This might help too, 2nd gen Repair Manual excerpt:

 

It's not that bad just takes practice

 

and the right tools

 

Watching YouTubes would help, nowadays, help you understand the tools and techniques. It was the dark ages when I (once) changed drum brake shoes. Ugh.

 

DANGER WILL ROBINSON. I did not look at the video
but the Prius is an odd beast. It has battery powered brakes. Make sure you disconnect the 12volt battery and wait the specified time for the brake capacitors to discharge. Otherwise you will have problems.

 

Yup, that's always step one. And before reconnecting the battery: pressure up the system with multiple brake pedal pushes, on the off-chance the system could detect excess brake pedal travel.

Maybe goes without saying, but don't use a memory saver device.

 

All drum brakes are similar in design and activation. Differences between manufactures seems to be around where springs are located.

Disengaging the return spring is a PITA! I can't see how mechanics can prevent the shoe from moving, causing the piston to move/dislodge, introducing air. When you work on it, you will see what I mean. The return spring is STRONG!!!!! A lot of force is required to disengage it.

Right tools is also having Techstream to bleed the system; you have determined you need to replace the rear drum cylinder (not caliper). You should be replacing the brake hardware (hold down springs, return spring, tensioner spring) too.

You should have access to a manual.

 

One thing, drum brake shoes last a long time. I resigned myself to just pulling the drum off once in a blue moon (official service interval ), lubing the contact points between shoe and backing plate, never needed to go further.

 

.? Only tools needed are flat blade screwdriver or the angled flat blade brake tool and a good set of needle nose pliers.

 

That's one of these?

 

The one on the left, they make slightly different ones. I recognize these, most you can get by without if you have a stocked toolbox, if not then u definitely need this.

 

The center springs are pretty easy to do with needle nose pliers. My shoes are like 3mm at 195k miles but I'm putting some grease on the contact points. Whatever.

 

Any idea how to correct problems if we did not remove 12v when changing cylinders and all, for rear brakes?
did i ruin accumulator?
i seems to run louder and longer...

Also would a heavier non OEM (steel) cylinder make a difference ?
otherwise brakes are good... better than she was... 04, 184k
thx

 

It would probably help to have more of the story.

You did some rear brake work, including changing cylinders?

What original complaint(s) led you to do that?

Did anything happen while you were doing the job to make you think "nuts, should have disconnected the 12V"?

If so, what did you do about it?

Since the job was completed, what current complaint(s) make you think something is amiss?

 

If you replaced the rear brake wheel cylinders, what procedure did you use to bleed them afterwards?

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