周一做了bleed break fluid,有空还要按坛子里资深的话再做一遍。目前上路没有负面影响。现在怀疑的是助力系统，其原理还不懂。
sienna的刹车行程估计约3.75英寸。踩下第一寸，怠速往前滑动的车可以停止；第二个一寸，有可听见的空气出来的声音；第三个一寸，出气声明显（象声：“出”或“尺”）；最后0.75“，抬脚用力时感觉好点，光靠脚尖难点。行程过长。这些基本是在怠速前滑下试验的。
注意是下踩时出声。我想在40迈以上恐怕是最后0.75“才能刹死车，这之前的出气没任何好处。booster破了？如何检查？正常情况助力系统的气压平衡如何工作的？看来管子太细行程没法缩短。
中午我再补充一下，关车是是否一直可以踩下3.75”。
与GS300比，记得40迈左右是第一个一寸没啥感觉，然后很灵敏又不过分（三菱有点过分），估计全行程2”车就刹死了。
网上有sienna刹车门还没引起重视：http://townhall-talk.edmunds.com/direct/view/.f0fa178/0
linea
Oct 23, 2006 (3:16 pm)
My Sienna 2005 experience intermittent complete brake failure 3 times within 18,000 miles,the brake pedal goes to the floor and it does not slow down, so I coast until I stop. However, when I release the brake pedal and then reapply the brakes, it works fine. A non-Toyota mechanic thinks it's due to malfunction of ABS. The dealership is unable to finds error codes and brakes work fine when the Sienna is in their hands. I scared that the brakes will not work the next time I reapply the brakes.
Has anyone else experience similar problem or have suggestings?。。。
Thanks for the suggestions. They have bleed the brake system and check the master cylinder, but Van brakes continue to fail intermittently.
by ckirk
Feb 08, 2010 (11:57 am)
Replying to: linea (Oct 27, 2006 5:39 pm)
I have experienced brake failure with 2004 xle awd. With no for-certain previous brake issues, in Nov, on totally dry street, was at 15-20mph when neighborhood dog strolled in front of us. I pressed brake progressively harder as the van barely slowed and the dog waddled just out of the way as we stopped just past him/her with brake pedal now to the floor.
I had had an experience last winter on the freeway when I slammed on the brakes to avoid pile-up and the van seemed to be slowing gradually. I hadn't noticed ABS pulsing and wondered at the time if the brakes were working properly. I'm not sure about last years event, but the dog was for certain brake failure. Dealer said he couldn't duplicate failure and all was well with pads, etc;
I've searched internet and have found linea's experience to be closest to mine. Any one else?
jeffst
Mar 01, 2010 (11:51 am)
Replying to: ckirk (Feb 08, 2010 11:57 am)
I've had a similar experience and just filed a complaint with the NHTSA. You should do the same if you haven't already done so.
I have a 2005 Sienna XLE. It happened just last week, once to my wife and once to me while trying to stop at an intersection. The road was not slick. I pressed the pedal as hard as possible. No ABS pulsing occurred. The pedal did not sink to the floor despite the amount of pressing. I also tried pumping the brakes as I slowwwly came to a halt.
The brakes have otherwise worked fine. Since the problem is intermittent, my mechanic is having problems diagnosing the problem. He thinks it may be a vacuum issue. Have you had a diagnosis yet?
by victor23
May 28, 2010 (7:18 am)
Replying to: audit2000 (May 22, 2010 9:33 am)
The brakes on my Sienna 2005 felt mushy since the day one. Quite many other people reported the same feeling.
Actually I am much more irritated by a very rapid wear of both front and rear pads, I have to change them every 10-15k miles in a mostly "suburban" driving, and as far as I could gather, this is also pretty typical for Sienna. I think maybe its Camry-like brakes are just inadequate for a minivan. Or maybe this is the electronic brake distribution thing, like with newer Honda Accords. This second hypothesis might explain why not everybody experienced this (not all Siennas were equipped with this option back then). Anyway, can't wait to see the reports about brakes of a next generation Sienna.
by lbiz
Jul 01, 2010 (12:11 pm)
Brakes would just not catch and hold. 13,600 miles on car. Toyota forensics said I was going 73mph AND braked 5 secs b4 impact adn was going 40 mph at impact. Would not stop by the time I reached stop sign and I hit another vehicle. Sienna caught on fire and a passerby pulled me from the vehicle. Boyfriend had broken back and neck. Grandson in second seat unhurt. Toyota forensics also indicated some problem with the brake. I crushed both feet trying to stop and in hospital a month. Even if toyota forensic are correct, shouldn't a vehichle go from 73 to 43 mph in 5 secs. Then the brakes so hot they caused the van to catch on fire. Any one else have problems with Sienna brakes?
