Parking Brake Adjustment -- Take II -- Or I request some guidance..

I think it's very important to know what you're doing with brakes. Anything that can go wrong....usually ends up costing your life or someone elses life.

 

Hmmmmm......
This is a wobbler (pun nearly unintended) but I would see if the local Autowhammy lends jack stands. Often some of the larger auto parts retailers will lend out tools with the hopes that you'll break something and need to buy some additional parts to fix the car.

If not, I'd consider a pair of jack stands anyway. They're cheaper than a ER co-pay and you'll probably find an excuse to go poking around beneath your car before the next year has elapsed.
If noting else you can yank the drum and clean things up....and maybe take a look at the other corners to see what's happening.

Old Man Winter is about to take up residence in some of the less fortunate parts of this nation, and they sometimes use salt and sand as friction modifiers where you live...er....are living now temporarily.

I'm curious about one thing though.....
The last time I was in Iowa it was flat enough to go without a parking brake.

No.....it's not Nebraska, where you can stand on a bucket and see the back of your head - but I'm thinking that this is a non critical repair.
JUST THE VERY REASON to go poking around inside the drum.....

Good Luck!

 

Gotta admit, I have never adjusted the parking brake on any car. I didn't even know it was a thing to maintain. Last I checked, the only people who used their parking brake drove standard or in other words no one uses their parking brake, except my wife and I.

 

I would agree with this sentiment.

Kris, you might also try backing up the car on a road with no traffic, and pressing the brake pedal hard a few times. Maybe you can get the automatic drum brake adjustment to take up some of the slack that currently exists.

Removing the drums for inspection is not difficult. If they do not pull off by hand when the parking brake is released, you would use a couple of metric bolts (8 mm) inserted into the drum to force the drum off.

If you are not able to obtain the proper tools now I suggest you wait until your return to Oregon.

 

Not sure what your going to do even if you get the drum off. It's probably pretty corroded in there and probably needs a full overhaul based on where you live and all the dirt roads it's seen. I'm saying if your going to go through the trouble of taking the drums off I would be ready to replace the shoes and clean and lube it.

Short of a overhaul the only quick thing you can do is adjust the star wheel. And thats available from the outside. There's a rubber plug on the top of the wheel. Take the plug off and there's a star wheel adjuster in there.With the back of the car up in the air pump the brakes a few times hard and then spin the wheel and adjust the star wheel with a screwdriver till the wheel stops. Then back off till you can just start to spin the wheel.

If you do want to take the drums off just to be safe I would unclick the power line off the 12 volt battery post fuse assy and unclick the thick cable.... it just unplugs...then push on the brakes a few times. That way you don't inadvertently push on the brakes with the hub off as you won't be able to get the hub back on.

 

M8x1.25 if it's the same as Gen 3, I'd assume so. You want the bolts to have about 1" of thread. The same size is used for the similar task of getting rotors to come off.

I got that info from "Eric the Car Guy" (Youtube). The first time I used the bolts, taking off a rotor, I was seriously sceptical that I had the right thread: it was really rusty and reluctant. Just keep screwing them in 'till they really start to seize, then back them out, blow out the rust dust, start again. Eventually you get them all the way through, and can get the bolt pushing against the backing plate. There's two bolts at 180 deg. So just give one a turn, then the other back and forth, 'till it pops off.

 

Prius drum brake is not the type that is adjusted by braking in reverse!
We do have rear disc brakes here but since I think it’s mostly American cars that use that setup I checked and Self-adjusters

It’s rare in any car that has rear drum brake that e-brake problems are caused by anything other than stuff in the brake itself. Mostly just automatic adjusters not working. Normally when the car gets old cables are stretched a bit. That can be seen by difference in place of pedal or leaver. But it is almost newer enough to cause e-brake not to have full strength.

Adjuster in the cable in Prius (and in other cars as well) is only for compensating for the stretched cable.

 

Not me I'll miss you.

Be careful. Jack up the rear and put some big logs under each side. Buy some brake cleaner and some lubricant first. And a roll of the blue paper towels sold in a parts stores. My favorite lube is CSP from Home Depot. Corrosion Prevention Spray. When you see an area you want to work on spray it clean with the brake cleaner. Anything that looks corroded under there hose it down with that lubricant. You may find the star wheel is hopelessly corroded. Get a hand mirror and a flashlight and take the plug off and see if you can see the adjuster wheel. You adjust it with an up/down motion of the screwdriver.

Dont forget to release the p brake after you get it up in the air. Spin the wheels and see how they sound. And while your under there spend some time looking at everything closely.

Good Luck!!!!!

 

Oh and I like to stretch for quite a while before I begin that. I'm speaking as someone who has hurt himself numerous times under a car.
It puts your muscles in positions you never ever use.

 

don't be too anxious, drum brakes aren't rocket science. I'll echo a few things others have said.

I'm lucky in my Gen 1 there's no need to futz with electric power before looking in the brake drums, but your Gen 2 apparently can do more automatic stuff when you might not expect it, so just as well to unplug the positive battery cable.

The Prius rear drum brakes, pace Patrick, are not the kind that self-adjust when you step on the brakes backing up. They are the kind that self-adjust when you ... use the parking brake. There you go - another reason to be the kind of driver who uses the parking brake routinely. If you don't, the rear brakes go gradually out of adjustment for normal braking too, not just for parking.

One thing that means is - if the star wheels do turn, they're not frozen up and the misadjustment is only because the parking brake hasn't been used regularly enough, you could get them back into adjustment just by applying and releasing the parking brake a whole bunch of times. Doesn't make you look nearly as dorky as the people who have the reverse-travel-adjusting kind of brakes, who have to keep backing up and jerking to a stop.

If they're badly out of adjustment that would take a while, as each apply-release of the parking brake will get you one star wheel click, changing the adjustment by a whopping 0.03 mm.

But that's assuming the star wheels really do turn, the adjusters aren't gunked up. That's where you really benefit from taking the drum off so you can really see what's in there. It won't burn your eye sockets, turn your hair to snakes or anything. You will see two brake shoes, a couple long springs that hold them pulled inward whenever your braking isn't pushing them outward, a couple coily springs that hold them in place, the parking brake levers, the adjuster with its star wheel, and the small adjusting lever that rides up and down over the star wheel teeth when you use the parking brake. It is set up so that if the shoes move more than the proper fractional millimeter, it slides up to the next tooth on the wheel, and pulls that tooth down when you release the brake.

It's all a lot easier to see than to describe. You can easily lift the adjust lever with a finger and see if the wheel turns easily underneath it. (Pay attention to how far you turn the wheel and get it back where you started, or spin it out several teeth's worth if you're already there because the adjustment's too loose.

If the star wheel is stuck and has been in one place too long, you will probably see that most of the teeth are pointy but the one the adjust lever has been rubbing up and down over is rounded off. If you see that, you need a new adjuster (they're cheap). Even if you free that one up again, it will probably work fine just until the rounded off tooth comes around again.

While you're in there, you'll see the overall condition of everything else, you can take pictures for PC if you have questions about anything. You'll get a sense of how thick the remaining linings on the shoes are, and whether they are wearing evenly or unevenly. It's all good stuff to look at now and then so there's an up-to-date picture of your car's overall condition in your head.

Adjusting the star wheel through the little rubber plug at the back is then something you can do as a shortcut in the future, if you ever need to. It makes a lot more sense after you've (at least one time) seen what it is you're actually manipulating in there.

As it happens, I've never had any need to touch the star wheels through the rubber plugs or do any manual brake adjustment; I use the parking brake every time I park, and that has been keeping everything right where it should be.

Removing the drum is a completely civilized and uneventful process as long as you use two 8 mm bolts in the holes provided for exactly that purpose, and just give them alternating little twists until the drum comes right off. You won't need to do anything special to put it back on, just slide it back on and reinstall the wheel.

It goes completely without saying but even I forget: the brakes (including the parking brake) do have to be released, or removing the drum will be really hard. You can easily check just by making sure you can give it a spin by hand, before you begin removing it.

You can probably spot the places (about 3 down the length of each brake shoe) where the shoes rest on little raised spots in the metal backing plate, and those are the 6 spots you might dab with some brake grease. Without getting into undoing any of the springs (that's not so much complicated, but the springs have minds of their own and you won't like what they're thinking), it's not hard to just pry the shoes up away from the back plate slightly, just enough to sneak in a grease dab on the tip of a small screwdriver for each of those contact spots, and let the shoes back down.

If the linings are really worn, or you see anything else that looks actually messed up, then you will have seen what's there, and will be able to judge whether you'd actually like to go the rest of the way and replace stuff, or have somebody else do it.

Cheers,
-Chap