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Discussion Starter · #1 ·
Hey, just recently my truck has started having a weird problem periodically. The emergency brake light comes on while driving and when you go to push the brakes the pedal goes all the way to the floor. It hardly wants to stop and sounds like the truck is coming apart underneath you. When you kill the engine the problem is gone when you start it back up. This is just slightly dangerous cause you never know when it's gonna strike again. Anyone have any idea as to what is causing this and if so, what's it gonna cost me to get it taken care of? :huh:
 

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the_kernel said:
Hey, just recently my truck has started having a weird problem periodically. The emergency brake light comes on while driving and when you go to push the brakes the pedal goes all the way to the floor. It hardly wants to stop and sounds like the truck is coming apart underneath you. When you kill the engine the problem is gone when you start it back up. This is just slightly dangerous cause you never know when it's gonna strike again. Anyone have any idea as to what is causing this and if so, what's it gonna cost me to get it taken care of? :huh:
What have you checked?

Brake fluid?

Brake Pads?

Rotors?

How many miles do you have on your truck?
 

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I have had same thing happen 3 times over last 3 years. I just turn truck off and restart problem goes away.Seems it only happens if brake check does not occur at 10 mph or whatever ever speed it is suppose to happen after initial starting of engine.
 

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Discussion Starter · #4 ·
37L1 said:
What have you checked?

Brake fluid?

Brake Pads?

Rotors?

How many miles do you have on your truck?
I didn't figure it was fluid, pads, or rotors since the e-brake light was coming on and it fixes itself when the truck is restarted (figured on computer or maybe ABS sensor) so I didn't check those things in regards to this issue. I have 37000 miles on the truck. I had the final judder fix like 3-5k miles ago though so the pads and rotors should be good. I dunno.
 

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I have had the same thing happen to me at least 4 different times. It's always right after start up and drive away at low speed. Scary if it happens at speed. If you find out the problem, please post it here.
 

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It sounds like some sort of vacuum leak to me, I haven't looked at the Titan's setup yet (but I will) normally there's a vacuum hose coming off the motor and into the servo for break assist and I would assume the titan is the same. At lower speeds there may not be enough vacuum built up and the peddle would drop a little and it would be quite hard to get the truck to stop (i.e. require a lot of leg effort) but I doubt it would go to the floor, makes me think something else might be wrong, I'll have a look at the system today and get back to you with my thoughts......

Good luck

--Jay
 

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Quick follow up question.

Do you guys remember if it happened on very humid days or was it a mixed bag on the temperature and humidity ?
 

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Discussion Starter · #8 ·
Johnny08 said:
Quick follow up question.

Do you guys remember if it happened on very humid days or was it a mixed bag on the temperature and humidity ?
It has happened to me at both high and low speed, dunno about the humidity though. It doesnt normally get too humid here in San Antonio though so I wouldn't think it would be that high. It's only happened to me at high speed once and that was on the interstate, but I guess it's possible I just didnt need the brake until I got up to speed and didn't notice until then. It grinds like the ABS is engaged once the pedal finally catches though.
 

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OK here's my .02

"It grinds like the ABS is engaged once the pedal finally catches" does the pedal vibrate as well ? This sounds like a cracked rotor to me, I would remove the rims and visually check each rotor and apply pressure on the rotor in places to help find any cracks...


However with the ebreak light coming on makes me think more on the electrical side, I just looked at my break servo and along with the vacuum pipe there are 2 sensors in the servo, each are tied into the master cylinder I'm assuming these are both for the automatic braking actuator one for an increase and the other for a decrease in pressure, if one of these was faulty you would have the symptoms you described BUT not have the grinding noise.

I guess you could have a bad rotor and a bad sensor but thats a long (ish) shot...

Does your truck have the adjustable pedals ? If yes then I would make sure the pedal motor is secure and not slipping a gear somewhere, this would give you a pedal to the floor and a grinding noise, but the breaks should still engage.


Lastly have you ever noticed more break dust on one wheel ?


If none of these revel an problems I would get it to the dealer and see if it trips a code for them, you don't want to be messing about with the break system too much...

Good luck.
--Jay

On a really far out there theory I would go with this, there is a diaphragm inside the servo, if this torn, or leaking the system is designed to lose all assist and the pedal becomes very hard, if the sensor for the assist was bad the system would not realize the servo was leaking and give the pedal too much leeway while looking for the assist from the servo (resulting in a long pedal) the long pedal uses the reserve break fluid and trips the ebreak sensor light on, telling you you need more fluid but after you restart the titan the sensor resets and pedal is working again, no ebreak light because the fluid has returned to normal again.

Thats so far out there i'm in another zip code but it's a possibility, I guess :smoke:
 

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Discussion Starter · #10 ·
Johnny08 said:
On a really far out there theory I would go with this, there is a diaphragm inside the servo, if this torn, or leaking the system is designed to lose all assist and the pedal becomes very hard, if the sensor for the assist was bad the system would not realize the servo was leaking and give the pedal too much leeway while looking for the assist from the servo (resulting in a long pedal) the long pedal uses the reserve break fluid and trips the ebreak sensor light on, telling you you need more fluid but after you restart the titan the sensor resets and pedal is working again, no ebreak light because the fluid has returned to normal again.

Thats so far out there i'm in another zip code but it's a possibility, I guess :smoke:
Actually, that makes a lot of sense to me. I don't think you're too incredibly far off base. Hmm. I really don't wanna shell out 100 bucks for nissan's diagnostic fee if I can help it so every little bit helps. Thanks for taking the time to help me out. :cheers:
 

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I think most of you guys are way off…

The fact that 3 different people say it goes away once you restart the truck make the source of the problem obvious to me.

It’s the ABS system going haywire for some reason. It thinks the truck is sliding for some reason. Possible problems? Sensor (wheel) computer, (bug in programming). Some weird thing that messes up the initial startup routine. Those systems are pretty complicated so you’re guess is as good as mine but If I was a betting man that’s were I would put my money…
 

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lowlypawn said:
I think most of you guys are way off…

The fact that 3 different people say it goes away once you restart the truck make the source of the problem obvious to me.

It’s the ABS system going haywire for some reason. It thinks the truck is sliding for some reason. Possible problems? Sensor (wheel) computer, (bug in programming). Some weird thing that messes up the initial startup routine. Those systems are pretty complicated so you’re guess is as good as mine but If I was a betting man that’s were I would put my money…
I wouldn't put all my eggs in the "ABS basket" why would the pedal be going to the floor, if an ABS sensor was bad ?

I agree it's very hard to trouble an issue without having the truck to look at but to say it's obviously the an ABS sensor, thats a bit much, don't you think...
 

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Johnny08 said:
I wouldn't put all my eggs in the "ABS basket" why would the pedal be going to the floor, if an ABS sensor was bad ?

I agree it's very hard to trouble an issue without having the truck to look at but to say it's obviously the an ABS sensor, thats a bit much, don't you think...
No way. If it was a mechanical problem like, rotor, vacuum leak (torn diaphragm) fluid leaking by the master cylinder the problem would be repeatable and would not be reset by simply restarting the truck.

I’m saying is has to be the ABS system, I’m no expert and could be totally wrong but feel very strongly that it’s the ABS.

Maybe someone who is an expert on how the ABS system works can confirm this but don’t the servos remove a little bit of brake pressure when the tires lock, and wouldn’t this cause the pedal to fall?

Also I know when I have played around with my ABS in the snow and ice it dose sound a lot like a “grinding” noise when activated. It’s also very similar sounding to the VDC when it kicks in during a slide. In fact with I 1st bought the truck and tried to do a fish tail the rain the VDC scared me until I got use to it. The ABS brakes also felt really weird at 1st. All of this personal experience really makes me think he is describing the ABS/VDC system. Which are really one and the same, just the computer telling it to do different functions,

To me there are simply too many things that point to the ABS system.
 

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Well I guess you know better than me... I should throw out that Bachelors Degree in Mechanical Engineering :)

NO NO seriously... I know what your saying about the electrical thought, just read the first part of my last post, I'm right there with you, BUT a bad ABS sensor would also be as repeatable.... since this was such a sporadic occurrence I was just making suggestions that were a little outside the box for everybody... not just a busted ABS sensor....

I would love to know what this turns out to be.. Galaxy, Kernal if you ever get this nailed down to a specific thing please keep us updated.

All the best.

--Jay
 

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I am thinking electrical too. Brakes work but act like they do with ABS engaged (pulsating pedal etc). It has never happened out of the blue, just right after starting and driving off. If you stop, turn off the key it re-sets and everything is normal.

Maybe I should have said electronic and not electrical. Computer glitch I am guessing. When you re-start, it re-boots.... Guessing.
 

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It has to be electrical, probably the abs computer. The abs system works by bypassing fluid if it senses wheel slippage, and it sounds like that is what is happening. If it was just one sensor it would only affect that tire, and not the rest. That is the reason I am saying it has to be the computer. If it was low on fluid, or anything else it would not fix itself by shutting the truck off. For some reason the computer is bypassing the pressure off the system to stop what it thinks is the wheel slipping, that is what the noise is.
 

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Discussion Starter · #17 ·
helomech said:
It has to be electrical, probably the abs computer. The abs system works by bypassing fluid if it senses wheel slippage, and it sounds like that is what is happening. If it was just one sensor it would only affect that tire, and not the rest. That is the reason I am saying it has to be the computer. If it was low on fluid, or anything else it would not fix itself by shutting the truck off. For some reason the computer is bypassing the pressure off the system to stop what it thinks is the wheel slipping, that is what the noise is.
That seems pretty logical too.
 

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Hey guys, I saw your topic and decided to review what you guys have had to say. I have a 2004 myself, and have experienced the same things you have with the ebrake light and loss of pedal pressure. I also have the same remidy...turning off the engine and restarting it, and the problem goes away. Keep me in the loop if you find out the cause of this problem.

Jay
 

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Discussion Starter · #19 ·
JollyGreen said:
Hey guys, I saw your topic and decided to review what you guys have had to say. I have a 2004 myself, and have experienced the same things you have with the ebrake light and loss of pedal pressure. I also have the same remidy...turning off the engine and restarting it, and the problem goes away. Keep me in the loop if you find out the cause of this problem.

Jay
I just got my warranty extended so I'll be taking it to the shop soon about this. I'll be sure and let you guys know when I find out.
 

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I know its probable not the same thing but I had a Chevy some years ago and one day I was having to push the pedal almost to the floor and the ebrake light would come on.
I got to checking it and it turned out the master cylinder had a leak. I am assuming the truck started using the ebrake to stop since there was not enough fluid to stop with the primary brakes.
________
Honda civic type r
 
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