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Bedding-Down Parking Brake

5K views 6 replies 3 participants last post by  bradly1101 
#1 ·
On p. 195 of the '17 manual it says this:

Drum-in-disc type parking brake system
Your vehicle has a drum-in-disc type parking brake system. This type of brake
system needs bedding-down of the brake shoes periodically or whenever the
parking brake shoes and/or drum are replaced. Have your Toyota dealer perform the bedding down operation.
I didn't know what bedding-down meant. After Googling it it sounds like heating up and cooling down of the shoes/drums repeatedly. I can't imagine a parking brake wearing out periodically, so does that mean you must take it in periodically to have this done? And what's the period? I don't see it mentioned in the maintenance schedule.

Is this done prior to delivery?
 
#2 ·
How do I say this, and keep this page "G" rated?

In this case, "bedding down" or "bed-in" of brake shoe material and the iron drum is more akin to the exchange of bodily materials, and the driving out of inhibitions......

So.... Brakes don't work well when the mating surfaces are completely dissimilar. Brakes work best when a bit of pad material makes it's way into the porous surface of the iron, and a tiny bit of iron makes it into the pad. When they become one by the exchange of materials, they bind together for maximum friction. The second aspect is that the heat drives out some of the adhesive resins that hold the pad fibers together, increasing the effective surface area.

As you use your parking brake in a stationary mode 100% of the time, you rarely do the above two actions. If you drive relatively slowly and lightly push on the parking brake, perhaps you could get them to slow the car without locking up the rears. Repeat it a few times in a safe place in case you overpush and lock up the rears. That would probably do the job.
 
#3 ·
LOL. Thanks for that. It would be nice if it had the old style parking brake that could be released without fully engaging it.

Do you guys (and gals) do this to your Siennas? I know I can ask the dealer, but is this common for them to do prior to delivery? Or do they expect you to have it done right away? What happens to a non-bedded parking brake? It won't hold the van?
 
#5 ·
It's certainly much harder with a push-on push-off system, or like in my Subaru, an electronically motor controlled system. I miss the old hand operated systems.

I never have done it, nor have I asked. I have to give this some thought.
 
#7 ·
In the official procedure from ECS, the starts and stops add up to over five miles. In the city I'm in there would be no safe place to do this unless going back and forth in a parking lot a bunch of times. People would think I'm crazy, and would probably lock the brakes up with this parking brake design. I've heard so many dealer nightmare stories that I don't think I'd trust them with this.
 
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