SIGforum.com    Main Page  Hop To Forum Categories  The Lounge    Toyota Sienna braking on downhills
Go
New
Find
Notify
Tools
Reply
  
Toyota Sienna braking on downhills Login/Join 
Serenity now!
Picture of 4x5
posted
We have a 2011 Toyota Sienna. Whenever we're driving on the freeway in the mountains (think I-80 in the Sierras, or between SLC and Park City etc), and we hit a downhill section, the van just takes off like a bullet. This makes us apply the brakes quite often to maintain control. But, when applying the brakes, we get a pretty strong vibration coming from the front, up into the steering wheel. It only happens after using the brakes for a while, so I'm guessing the heat from braking may be warping the rotors? After things cool down, the brakes are fine again.

We've got a trip to Lake Tahoe coming up, and I'm not looking forward to the drive between Carson and Tahoe, so I'm looking for advice on what might be the problem, and what we can do about it?

Thanks



Ladies and gentlemen, take my advice - pull down your pants and slide on the ice.
ʘ ͜ʖ ʘ
 
Posts: 4923 | Location: Highland, UT | Registered: September 14, 2006Reply With QuoteReport This Post
St. Vitus
Dance Instructor
Picture of blueye
posted Hide Post
Just wondering is this with cruise control on?
 
Posts: 5298 | Location: basement | Registered: April 06, 2007Reply With QuoteReport This Post
Serenity now!
Picture of 4x5
posted Hide Post
quote:
Originally posted by blueye:
Just wondering is this with cruise control on?


Sometimes, yes. But we've learned that even with CC on, the van accelerates very quickly, and find ourselves riding the brakes for safety.



Ladies and gentlemen, take my advice - pull down your pants and slide on the ice.
ʘ ͜ʖ ʘ
 
Posts: 4923 | Location: Highland, UT | Registered: September 14, 2006Reply With QuoteReport This Post
Not really from Vienna
Picture of arfmel
posted Hide Post
Downshift the transmission to let the engine help with braking? At least turn off the overdrive. There may be a section in the owner's manual that addresses driving in the mountains.
 
Posts: 26852 | Location: Jerkwater, Texas | Registered: January 30, 2007Reply With QuoteReport This Post
Doing my best to shape
America's youth
Picture of MooneyP226
posted Hide Post
Drive like a trucker?

Before heading downhill, choose a "safe speed". Decelerate to 5-10 mph below that and turn off overdrive/ manually put it in the next lower gear.

When vehicle accelerates to your chosen speed, firmly apply brakes (not stomping on them) until you reach the original speed.

Release brakes when that speed is reached.

Repeat as necessary.

Riding them will overheat them and failure will eventually happen. Nothing good would come of that.

Get your rear brakes checked as well. They may be stuck in the open position. Also check your brake fluid. If this is a constant issue, your fluid may have been cooked. See if it is black or smells bad.




Clarior Hinc Honos

BSA Dad, Cheer Dad
 
Posts: 1624 | Location: on the 42nd parallel  | Registered: November 19, 2013Reply With QuoteReport This Post
Member
Picture of 4MUL8R
posted Hide Post
If rotors are worn thin after six years, heat could temporarily distort. Measure and replace if required. OEM parts preferred, but most folks buy cheap iron from China.


-------
Trying to simplify my life...
 
Posts: 5041 | Location: Commonwealth of Virginia | Registered: January 15, 2007Reply With QuoteReport This Post
His diet consists of black
coffee, and sarcasm.
Picture of egregore
posted Hide Post
How many speeds in your transmission? I'll guess a 2011 is a five-speed. Fifth is a rather extreme overdrive, which will give you little or no engine braking, and fourth might be too. Shift down to at least fourth before descending such a steep grade. Don't carry engine braking to extremes and over-rev the engine, however. Brakes are cheaper to replace than engines. Also not recommended to use the cruise control on steep downgrades. It can maintain speed or accelerate, but can't slow you down.

quote:
But, when applying the brakes, we get a pretty strong vibration coming from the front, up into the steering wheel.

Pulsation from the rotors warping. This will eventually become permanent. Does the pedal get soft? This is an indicator of brake fluid boiling. This normally takes a lot of heat, but if the fluid gets any moisture in it, the threshold will be greatly reduced, as water boils far sooner than brake fluid. At this age you might consider having this fluid flushed out.
 
Posts: 27835 | Location: Johnson City/Elizabethton, TN | Registered: April 28, 2012Reply With QuoteReport This Post
His diet consists of black
coffee, and sarcasm.
Picture of egregore
posted Hide Post
If I'm descending a long grade and brake, my 2009 Corolla (four-speed auto) will downshift to third by itself and maintain it until such time as I stop gaining speed. Sure, I could do the same thing myself, but it does it so well I don't need to. Yours doesn't do that?
 
Posts: 27835 | Location: Johnson City/Elizabethton, TN | Registered: April 28, 2012Reply With QuoteReport This Post
Would you like
a sandwich?
Picture of Dreamerx4
posted Hide Post
I have a 2011 Tacoma that does same exact thing.

Your rotors are warping with the heat as you stated.

I bought high performance rotors and pads, best price was amazon actually after a search, rotors have groves and are drilled for heat dissipation.

Perfectly smooth now.

Think I had $170 ish into it for front rotors and pads.



 
Posts: 1044 | Location: Virginia | Registered: October 29, 2007Reply With QuoteReport This Post
Drill Here, Drill Now
Picture of tatortodd
posted Hide Post
If it were me, before the trip to Lake Tahoe I'd have the front brake pads and rotors replaced (or DIY) and rears inspected.

On the drive to Tahoe, I'd downshift before a long downhill descent so the motor is braking. Most highways have signs notifying of length and grade of descent so you'll know ahead of time to downshift at the crest.



Ego is the anesthesia that deadens the pain of stupidity

DISCLAIMER: These are the author's own personal views and do not represent the views of the author's employer.
 
Posts: 23102 | Location: Northern Suburbs of Houston | Registered: November 14, 2005Reply With QuoteReport This Post
Middle children
of history
Picture of Brett B
posted Hide Post
If the pulsation is not permanent, meaning it only comes on after you have really heated up the brakes during a long downhill stretch, it may not be warped rotors. You could be overheating the pads and they are depositing what is essentially melted pad material onto the rotor surface. This feels exactly the same as warped rotors but is a different cause and thus a different fix.

So I agree that you should check the rotors for warping and replace if needed with some good quality OEM rotors that aren't as prone to warp. But also look at new pads as thin heavily used pads overheat (and boil brake fluid) much more easily than new thicker pads due to the mass involved. Better quality pads that don't break down until a higher temperature are also worth looking into.


-------------------------
SCAR forend upgrades:
www.regosys.com
www.instagram.com/regosystems/
 
Posts: 2597 | Location: Midwest | Registered: September 06, 2008Reply With QuoteReport This Post
Member
Picture of fwbulldog
posted Hide Post
To avoid excessive speed going downhill find and use the overdrive lockout. That button will stop the transmission from shifting into the highest gear.


If turning off the OD doesn't slow you down enough, then brake until you can manually down shift to 2nd. Typical speeds around 35ish. Your manual probably had a section on this topic.


Let the motor do the work. I've lived in Colorado most of my life, and have watched a lot of brake fires and failures happen because people just aren't aware they should downshift. I see lots of trucks on the side of Vail Pass and Silverthorn sitting there burning or buried deep in the runaway ramps. Even professional truckers don't always know how to do it correctly.

Stay right, slow down, get there alive with all your metal parts unmelted. Enjoy the smell of victory as you watch all the noobs go flying by with smoking wheels.


_________________________
You do NOT have the right to never be offended.
 
Posts: 3015 | Location: Round Rock | Registered: February 11, 2004Reply With QuoteReport This Post
Member
Picture of MO-Sig
posted Hide Post
I had the same experience in our 2010 Highlander the first time we took it on I-70 from Denver to ski country. The next year I used the transmission and stayed in a lower gear and had no vibration and good pedal feel the entire time.



This is what happens when you stop letting kids play dodgeball in school.
 
Posts: 475 | Location: Fly Over Country | Registered: October 22, 2010Reply With QuoteReport This Post
Just because you can,
doesn't mean you should
posted Hide Post
Cruise control should disengage when you apply the brakes so that's not the problem.
What kind of brake pads and rotors are on the car? I would bet they are an off-brand.


___________________________
Avoid buying ChiCom/CCP products whenever possible.
 
Posts: 9456 | Location: NE GA | Registered: August 22, 2002Reply With QuoteReport This Post
Member
posted Hide Post
Strange seeing this thread. I have a 2012 Sienna that we took on vacation last April and it included lots of steep grades at various locations including in Utah in the ski resort areas of the Wasatch mtns and on I-70 on our return trip through Colorado from west to east. Never experienced anything like what you are reporting.
 
Posts: 693 | Location: E. Central Missouri | Registered: January 05, 2011Reply With QuoteReport This Post
  Powered by Social Strata  
 

SIGforum.com    Main Page  Hop To Forum Categories  The Lounge    Toyota Sienna braking on downhills

© SIGforum 2024