2 problems related??

My 2013 does a weird thing when I first start driving it where the brakes seem like they are applying themselves or like the pads or calipers are sticking to the rotor and dragging or pulsing. It only last a few seconds and it feels similar to abs trying to kick in and then it stops for the rest of the time I'm driving it. It's not throwing any codes according to the mechanic I took it to and he said I will have to take it to the dealer. Also the cruise won't stay set and was wondering if it's a vacuum leak that could be related to the brake problem somehow? Ignorance abounds so don't laugh too much, that's why I'm asking you Yotaheads. This is my first Toyota and I've only had it about six months and so far I love it and want to get those two problems fixed! Thanks Guys!

 

The brake "booster" is all electronic on TRD OR's (seeing your truck description), not vacuum operated like the non-TRD trucks.

 

OK, that's good to know. Yeah I called it a booster cause my old fart mind couldn't think of master cylinder at the time!

 

I think we need more info about when it happens and what it feels like.

So, it happens first thing in the morning when cold, but not later? Do you back out of the driveway and then it does it when you move forward? And is it a vibration? Or more like you're giving it gas but it isn't moving? Can you hear anything with the windows down?

 

Yes first time and yes I back down the driveway onto the street which is also uphill so I'm backing uphill and I can put it in neutral or drive and it doesn't want to move and when I give it gas it starts moving like the parking brake is on (but I never set it) or the calipers are locking up and dragging with vibration and noise. I can tell it's definitely coming from the front.

 

throwing this out there, but cruise gets disengaged any time you tap on the brakes, so maybe something is causing the brakes to be applied without your foot? might not explain why you only feel it at cold though...

 

When you park, do you set the parking brake?

 

It's got a Gremlin in it messing with me! It is an odd problem, just my luck!

 

If your brakes seem to be dragging and the cruise wont set, maybe the brake pedal switch isn't adjusted properly?
(automatics only because I think the cruise switch is on the clutch pedal in manual transmission trucks)

 

No, I never set the parking brake, probably should but I don't!

 

I'd place my bets here.

 

Sounds feasible to me, I'll see if I can get my old self down there to check it. Thanks!

 

That is the Hill Assist Control (HAC), Downhill Assist Control (DAC) doing what it is designed to do.

How HAC Works
Let's begin by explaining that this isn't a new technology, it has been around for a while on various different models of cars, what is new, is the way in which this system works. Other cars, such as a Volkswagen Golf, have a system that locks the brakes completely if the car is at more than a 5° angle. How HAC works in Toyotas is that if there is any backward movement detected by the plethora of on-board sensors, the car with immediately play around with the pressure of the brake fluid as your foot is lifted from the brake pedal. Essentially, it slows down the reduction in brake pressure to give you the ideal starting point for a hill-start. Keeping the brakes applied minimally until the correct torque is reached for the car to begin to move forward where it releases the brakes, allowing for a smooth take off.

This may seem a bit redundant to people who only do city driving, but out on slippery surfaces or large inclines, it comes into its own. There is a video from Toyota that shows this system in action. It shows quite nicely how this type of technology can be used to prevent not only the downhill roll that often comes with a hill-start but also the torque-steer or loss of traction from having different wheels on surfaces with a different coefficient of friction. As the video shows, instead of the car rolling backward before either the brakes are applied or the driver hits the accelerator it gradually creeps forward. Whereas the car without the system tries the usual maneuvers that all drivers do in these situations, only to find themselves rolling backward with an increasing number of revs coming from the engine. Or having one wheel spin on a surface with no purchase and the car twisting upon its axis.

How DAC Works
This system is for the other side of the hill you've just ascended. It works by noting the incline of the hill, presumably with the same sensors that work for the HAC. From here, the system keeps the speed of the car below 15mph. Working alongside the ABS and traction control built into the car, it constantly monitors and adjusts the amount of power and brakes applied to each wheel, allowing for the car to safely negotiate difficult terrain. It removes a lot of the driver error involved in going downhill. If you've ever attempted it you will know how easy it is for you to let the car run away from you slightly, build up speed, and as soon as you apply the brakes these a slight skid until you regain some traction. More often than not, this isn't a problem, but every now and again, should there be a rock or something that can do untold damage to your car then it helps to have these little electronic assists. Again, Toyota has released a video that explains how this system works.

It again may seem a bit redundant to many users of the car. Seeing as the car already comes with anti-lock brakes and traction control that work together to eradicate these issues, but by having an electronic algorithm built into the fabric of the car that will make the decisions of when the brakes should be applied and how much power to apply to each wheel simultaneously, all the while maintaining a safe speed, it really does add a bit of extra gravitas to the car. Especially if your day will consist of going down wet, steep, bumpy roads.

 

Any codes,ABS problem ?

 

Does a 2013 Off Road have these? My '14 Sport doesn't. My wife had a Jeep Liberty that had it. When parked on an incline in the driveway it would sit there in drive until you gave it some gas and the brakes would release. My Tacoma will roll backwards out of the driveway while in drive if I don't keep a foot on the brake pedal.

 

No, no codes, I checked it with my Torq App.

 

Eureka!! That's gotta be what I am experiencing... I read about both in the owners manual but I guess I didn't put 2 and 2 together! Well, now I really feel stupid but VERY GRATEFULL for this explanation! Thank You Notoneiota! Now what do you think is causing the cruise not to set or stay set??? The switch on the brake pedal as mentioned??

 

Thanks JimmyH! I see now that you posted this first so you deserve full credit for figuring out my problem. Dang truck is way smarter than me! Didn't have all these assists on any of my Jeeps I'v had in the past and this is my first Toyota! Digging the Tacoma, should've got one sooner! Thanks Again!!

 

I really couldn't say if you do or not. Check the VIN against a VIN Decoder.

 

Glad to have cleared that up for you.

The brake switch would be a good starting point for the cruise control issue also the spiral cable.