Parking Brake Adjustment - Toyota Sienna Forum - siennachat.com
 
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post #1 of 15 (permalink) Old 07-27-2010, 09:54 PM Thread Starter
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Parking Brake Adjustment

We have a 2006 XLE LTD and I think the parking brake/emergency brake needs adjustment. It used to work fine, but lately there is a lot of travel in the pedal (i.e., I can basically push it all the way down to the floor) and it won't hold the van at all, even on a mild incline.

Is this something that I can adjust myself? Keep in mind that I am not all that mechanically inclined, though I can do simple things. Can I just try to take up the slack in the cable somewhere? Also, isn't the e-brake supposed to be self-adjusting? Is there a good way to kickstart the automatic adjustment process?

Or am I better off taking this to the dealer?
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post #2 of 15 (permalink) Old 07-27-2010, 10:47 PM
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Re: Parking Brake Adjustment

I think your vehicle has rear disc brakes I know that rear drums are self-adjusting-when working properly, they "adjust" while the vehicle is moving backwards and the brakes are applied. I don't know if discs have a "self-adjust" feature.

Did the parking brake slowly lose it's grip or did it just suddenly go loose?

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post #3 of 15 (permalink) Old 07-27-2010, 10:53 PM Thread Starter
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Re: Parking Brake Adjustment

Quote:
Originally Posted by 94dlx
I think your vehicle has rear disc brakes I know that rear drums are self-adjusting-when working properly, they "adjust" while the vehicle is moving backwards and the brakes are applied. I don't know if discs have a "self-adjust" feature.

Did the parking brake slowly lose it's grip or did it just suddenly go loose?
Yes, you are correct, rear disc brakes. My (albeit extremely limited) understanding is that vehicles that have rear disc brakes have to have other mechanism for the parking brake. The dealer said something about a pad that actually immobilizes the driveshaft. Even then, I thought it had some kind of self-adjustment.

My wife drives the car most of the time, so I don't know. She never mentioned it, but I immediately noticed the difference when I drove it. I guess that points to something that happened slowly over time.
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post #4 of 15 (permalink) Old 07-27-2010, 11:26 PM
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Re: Parking Brake Adjustment

Quote:
Originally Posted by 94dlx
I know that rear drums are self-adjusting-when working properly, they "adjust" while the vehicle is moving backwards and the brakes are applied.
Yes, that's a normal feature of modern drum brakes.

Quote:
Originally Posted by 94dlx
I don't know if discs have a "self-adjust" feature.
Yes, disc brakes inherently self-adjust, because there is no mechanism to push the pads significantly away from the disc (rotor) after they are applied. Each application brings them to a new and properly adjusted rest position.

However...
Quote:
Originally Posted by newbs
My (albeit extremely limited) understanding is that vehicles that have rear disc brakes have to have other mechanism for the parking brake.
The above is basically true. The basic disc brake caliper doesn't have a parking function. There are three ways around this:
  • also have a separate caliper for parking which is not run by the regular hydraulic system [rare, mostly on exotics with race-style main brakes]
  • include a mechanism in the caliper in addition to the hydraulics to apply the pad for parking [many cars have this, but generally not Toyotas]
  • equip the rear with both hydraulic disc brakes (for regular braking) and a separate drum brake (only for parking) [this is the typical Toyota solution, and the Sienna's system]


Quote:
Originally Posted by newbs
The dealer said something about a pad that actually immobilizes the driveshaft.
If in doubt, assume the dealer is wrong... he usually is.

It is common for trucks to have a big drum brake on the driveshaft; my rear-disc-equipped motorhome has one of these. No modern car or light truck would use this system. Heck, a two-wheel-drive Sienna doesn't even have a driveshaft on which to install this... it would have to be inside the transmission.

The transmission's "Park" position is essentially a brake inside the transmission, but it's not a friction pad, it's more like a lock mechanism; it is not what the parking brake pedal applies.

Quote:
Originally Posted by newbs
Even then, I thought it had some kind of self-adjustment.
The rear-disc-equipped Sienna's parking drum brakes are not self-adjusting, because the practical self-adjustment design works when the brakes are applied while moving backwards (see the comment above by 94dlx), and the parking brake is not applied while moving (in any direction).

The parking brake cable and pedal mechanism probably does have a self-adjuster to take up the slack caused by cable stretch, but it may not be able to compensate for wear in the parking brake shoe linings themselves... and why would they wear, anyway? They should never wear, because they should never slide, because the vehicle should never move with them applied. Having said that, I have started to drive with the parking brake accidentally left on, and it is easy to do because it is so ineffective that the engine very easily overpowers the parking brakes. I suppose that my parking brake shoes do have some wear, but when I replaced my rear rotors (at over 100,000 km, regularly using the parking brake) the parking shoes didn't look worn.
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post #5 of 15 (permalink) Old 12-17-2010, 12:11 AM
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Re: Parking Brake Adjustment

I agree. Our Sienna was just at the dealership to address the lack of "holding power" from the park brake. It was adjusted, however there is little difference. Beware of the parking brake system, it is barely adequate.
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post #6 of 15 (permalink) Old 12-17-2010, 01:16 AM
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Re: Parking Brake Adjustment

Quote:
Originally Posted by Linden
... Beware the emergency brake system, it is barely adequate.
Probably because it is NOT intended to be used as an "emergency" brake.

The owner's manual calls it a "parking" brake.

A somewhat proper "emergency" brake would need the capability of modulating the braking effort.
It's not impossible with the pedal-operated system, but it is rather difficult.

.
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post #7 of 15 (permalink) Old 12-17-2010, 10:37 PM
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Re: Parking Brake Adjustment

Datsa Noydb posted exactly what I was going to say... so "ditto".
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post #8 of 15 (permalink) Old 01-07-2011, 12:51 AM
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Re: Parking Brake Adjustment

I just adjusted our 2001 Sienna cable which also didn't pass inspection. Under the car, about where the driver's seat is, the cable from the pedal has a threaded end that holds the two cables leading to the rear wheels. Two nuts tightened against each other set how much play the cable has. I had about 1" I could easily tighten the cable which should now pass inspection.
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post #9 of 15 (permalink) Old 01-10-2011, 12:32 AM Thread Starter
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Re: Parking Brake Adjustment

Quote:
Originally Posted by catfish
I just adjusted our 2001 Sienna cable which also didn't pass inspection. Under the car, about where the driver's seat is, the cable from the pedal has a threaded end that holds the two cables leading to the rear wheels. Two nuts tightened against each other set how much play the cable has. I had about 1" I could easily tighten the cable which should now pass inspection.
Can you give me a better idea of what I am looking for? Keep in mind that until today, I have never crawled underneath any car I have owned, which gives you some idea of how (in)experienced I am at working on cars. Anyway, I did look at the underside of our 2006 Sienna, but I did not see anything that looked like the parking brake cable, nor did I see any screws that looked like they could be adjusted.

How far back from the front wheels should I be, and I should I be in the middle of the van or towards the edges/doors?

Thanks!
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post #10 of 15 (permalink) Old 01-10-2011, 01:49 AM
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Re: Parking Brake Adjustment

Looks that adjusting screw is closer to the pedal. See the attached file.

Also I suggest to download 2005 Sienna Repair Manual:
http://siennachat.com/forum/index.php/topic,805.0.html

Romualds
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Mods to meet European rules: http://www.siennachat.com/forum/index.php?topic=324.0
Download 2005 Sienna Repair Manuar here: http://www.siennachat.com/forum/index.php?topic=805.0
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post #11 of 15 (permalink) Old 01-10-2011, 04:30 AM Thread Starter
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Re: Parking Brake Adjustment

Quote:
Originally Posted by Romualds
Looks that adjusting screw is closer to the pedal. See the attached file.

Also I suggest to download 2005 Sienna Repair Manual:
http://siennachat.com/forum/index.php/topic,805.0.html
Thanks. That picture helped quite a bit. I was able to tighten up the adjusting nut a bit, and it seems like pedal feels a little better. I'll have to test it out on an incline. Incidentally, the locking nut was missing (which is probably why the pedal loosened up in the first place). Is there something I can get at Home Depot that will work?
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post #12 of 15 (permalink) Old 01-31-2011, 09:12 PM
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Re: Parking Brake Adjustment

On my 2002 Sienna, with 173,000 miles, I happen to live in a mountain village in rural Puebla Mexico. It is so hilly there aren't many places I can even check the oil. I park on some horrendous hill streets, and my parking brake is very strong. Once I push that sucker in, the car is not moving until I release it. And, I have never adjusted it yet, though I do know how.
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post #13 of 15 (permalink) Old 02-03-2011, 09:37 PM
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Re: Parking Brake Adjustment

Quote:
Originally Posted by newbs
Incidentally, the locking nut was missing (which is probably why the pedal loosened up in the first place). Is there something I can get at Home Depot that will work?
Building supply stores tend to have a poor selection of threads, particularly in metric (they may only have something coarser than you need, even if they have the same diameter). Anything but the smallest city should have industrial supply or specialty fastener stores, which would have the nut... if it is just a plain nut (likely a thin one, if it is just a jam nut).

In the worst case, if Toyota lists the nut as a part which can be purchased by itself, you can pay ten times what it is worth and get it from a dealer... and still only pay a couple of dollars.
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post #14 of 15 (permalink) Old 07-28-2013, 08:52 PM
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Re: Parking Brake Adjustment

Hey, I realize this is way too late for the original poster, but I wanted to clarify on this a bit for new readers.

I just finished rebuilding my parking brake and replacing my rear rotors and brake pads on a 2010 Sienna XLE.

The rear brakes are both disc AND drum brakes. Without even taking off the tires, notice how the rotors have that huge drum in the middle ? Inside that is a traditional cable actuated bendex style drum brake. It looks like and works exactly like every bendex style drum brake you've ever worked on, complete with the star adjuster but with one minor (well, major?) difference; there is NO self-adjuster arm. The brakes have to be manually adjusted via the star adjuster, just like normal drum brakes, the difference being that with normal drum brakes you would adjust until they're "kinda close" to engage the drum, then do the old back-up self-adjustment thing. that won't work on this, since there is no self adjuster. Instead, you have to adjust it yourself.

To do so, pull the wheel and rotate the disc until that little rubber plug is at the very bottom, at the 6 o'clock position. Pull that plug out, stick in a screwdriver and angle it high up, so that the blade of the screw driver is pointing downwards. Feel for the adjuster, and rotate it downwards. This will expand the adjustment bar, which will push the pads out.

The posts I've read about adjusting at the pedal are fine if you're issue is cable slack, but you should really be adjusting the pads before worrying about taking out cable slack (major adjustment, versus minor adjustment).

Here's what the inside of the parking brake drum looks like:
http://www.villagetoyotaparts.com/sh...=parking+brake

The star adjuster in this picture is part 47405. The diagram doesn't show the teeth very well (which is why it has the nickname star adjuster) but that's the one.

Good luck !
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post #15 of 15 (permalink) Old 07-31-2013, 09:01 AM
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Re: Parking Brake Adjustment

I'm just going to add one comment to HiI'mMatt's excellent post, because I pretty much know why he had to "rebuilding my parking brake" while doing his pads on a 3 year old Sienna.

STEP #1: go to that star adjuster under the rubber plug at the 6 o'clock position and pull the parking brake shoes inward (rotate it upward to retract the adjustment bar). If you do not, you will rip the little shoes from their backing plate and destroy the hardware in the process of removing the rear rotor! Just ask Matt how frustrating this can be....

Why? Even thought the shoes are not in contact with the inside of the mini-drum when the parking brake pedal is not engaged, a rust ring forms at the edge of the 'hat' and the pads cannot clear this. Essentially they are in a groove path, and you must pull the shoes in beyond this - by as much as a full quarter inch. If you plan on reusing the rotor, strip this ridge away and expand your shoes a few turns of the star prior to putting the rotor back on so that you don't need to spend so much time moving the star gear a tooth at a time later thru the access hole.

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