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Old Dec 23, 2014 | 06:45 PM
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Vibration

In my 2008 F150 with 108,000 miles, I am having a vibration in the brake pedal. When I am stopping or at a dead stop. I first thought it might be the rotors needing to be turned, but the vibration seems to go away when I turn off the a/c.

Any ideas??
 
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Old Dec 23, 2014 | 08:10 PM
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when you turn on the air conditioner, the clutch locks up and the compressor starts turning. I doubt the compressor has a vibration. I would guess the extra load of the compressor slows the motor RPM down 50 RPM and the motor is running a little slow and you feel the imbalance. When you are setting idle, turn the AC on and feel the vibration... then push the gas pedal down a little so the motor speeds up 100 RPM and see if the vibration goes away.
 
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Old Dec 23, 2014 | 08:11 PM
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I will try that tomorrow.
 
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Old Dec 25, 2014 | 03:16 PM
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There is supposed to be some device to add throttle when the compressor kicks in to maintain proper idle speed. This was a mechanical system in the old days but is a program now. If the compressor slows the idle there is a problem.
 
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Old Dec 26, 2014 | 10:09 AM
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Originally Posted by Supercrewzin01
In my 2008 F150 with 108,000 miles, I am having a vibration in the brake pedal. When I am stopping or at a dead stop. I first thought it might be the rotors needing to be turned, but the vibration seems to go away when I turn off the a/c.

Any ideas??
Vibration in the pedal typically means the rear rotors are warped, resurfacing should run. $15 to $25 for each rotor
 
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Old Dec 26, 2014 | 11:38 AM
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Originally Posted by novuswsr
Vibration in the pedal typically means the rear rotors are warped, resurfacing should run. $15 to $25 for each rotor


Rotors will not vibrate at a dead stop.
 
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Old Dec 26, 2014 | 11:59 AM
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Originally Posted by critterf1
Rotors will not vibrate at a dead stop.
Thanks for that captain obvious. How bout we just provide information that may help the situation
 
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Old Dec 26, 2014 | 05:36 PM
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I just went for a drive, and it seems like the RPMs get too low and the vibration starts. According to my tach it's getting around 600 RPM and then it starts. These trucks don't have IAC's so could it be TPS?
 
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Old Dec 26, 2014 | 10:37 PM
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Originally Posted by Supercrewzin01
In my 2008 F150 with 108,000 miles, I am having a vibration in the brake pedal. When I am stopping or at a dead stop. I first thought it might be the rotors needing to be turned, but the vibration seems to go away when I turn off the a/c.

Any ideas??
Originally Posted by novuswsr
Vibration in the pedal typically means the rear rotors are warped, resurfacing should run. $15 to $25 for each rotor
Originally Posted by critterf1
Rotors will not vibrate at a dead stop.
Originally Posted by novuswsr
Thanks for that captain obvious. How bout we just provide information that may help the situation
Novuswsr, welcome to FTE. Being new here you might be pleasantly surprised to find that FTE isn't like a lot of other forums where people post in an abrasive, condescending, or flaming manner.

Your post that I quoted in bold above fits in the category of abrasive and condescending. Yeah, I know, I'm being obvious....(pun intended)

Keep it easy-going when you post bud. We like to enjoy our tech forums, not foment or stir up negative emotions. In the vernacular of todays younger folk, that aint how we roll, here.

Now, all of that aside, your Captain Obvious post really missed the target. CritterF1 pointed out something that you completely missed in the OP's first post.

Here, I'll highlight it below for ya, in the re-quoted post:

Originally Posted by Supercrewzin01
In my 2008 F150 with 108,000 miles, I am having a vibration in the brake pedal. When I am stopping or at a dead stop. I first thought it might be the rotors needing to be turned, but the vibration seems to go away when I turn off the a/c.

Any ideas??
So as you can see, critter was pointing out something you had missed when you posted up for the OP to have his rotors turned.

Sometimes, even OBVIOUS things in a post still need to be pointed out.

Critter (Captain ) thanks for pointing out what was missed. You can ask the guys in the Ex forum, I have a really bad habit of glancing over/speed reading a post, so I miss stuff like novu did here in this thread.

Stewart
 
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Old Dec 26, 2014 | 10:56 PM
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Originally Posted by Stewart_H
Novuswsr, welcome to FTE. Being new here you might be pleasantly surprised to find that FTE isn't like a lot of other forums where people post in an abrasive, condescending, or flaming manner.

Your post that I quoted in bold above fits in the category of abrasive and condescending. Yeah, I know, I'm being obvious....(pun intended)

Keep it easy-going when you post bud. We like to enjoy our tech forums, not foment or stir up negative emotions. In the vernacular of todays younger folk, that aint how we roll, here.

Now, all of that aside, your Captain Obvious post really missed the target. CritterF1 pointed out something that you completely missed in the OP's first post.

Here, I'll highlight it below for ya, in the re-quoted post:



So as you can see, critter was pointing out something you had missed when you posted up for the OP to have his rotors turned.

Sometimes, even OBVIOUS things in a post still need to be pointed out.

Critter (Captain ) thanks for pointing out what was missed. You can ask the guys in the Ex forum, I have a really bad habit of glancing over/speed reading a post, so I miss stuff like novu did here in this thread.

Stewart
Points well taken, thanks
 
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Old Dec 26, 2014 | 11:06 PM
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Originally Posted by novuswsr
Points well taken, thanks


Stewart
 
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Old Dec 28, 2014 | 08:07 AM
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Is there a way to fix the rpm problem?
 
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