Brake pedal clunk
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Joined: Dec 2021
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From: Greenlawn NY
Brake pedal clunk
Good evening all
I bought a 2021 Ranger XLT in December 2021. Over the past month I have noticed on occasion a chunking noise coming from the brake pedal when I release the pedal. Also a whooshing noise every once in a while when applying the brakes that is coming from the pedal area. So I brought the truck back to the dealer that I bought it from to have the noise checked out. The dealer tells me that the noise is normal and that they have a truck just like mine at the shop and that one makes the same noise so its normal. I have been around cars and trucks a long time and my first guess would have been a defective power brake booster assembly. Has anyone else experienced this noise?
Thanks
I bought a 2021 Ranger XLT in December 2021. Over the past month I have noticed on occasion a chunking noise coming from the brake pedal when I release the pedal. Also a whooshing noise every once in a while when applying the brakes that is coming from the pedal area. So I brought the truck back to the dealer that I bought it from to have the noise checked out. The dealer tells me that the noise is normal and that they have a truck just like mine at the shop and that one makes the same noise so its normal. I have been around cars and trucks a long time and my first guess would have been a defective power brake booster assembly. Has anyone else experienced this noise?
Thanks
The noise "can be" normal
Power assist brakes use outside air pressure to assist the driver to push down on the pedal
The booster has 2 chambers
Vacuum side gets the negative pressure from engines intake vacuum, so below outside pressure
When you press down on the pedal that opens the atmosphere valve at the base of the brake pedal push rod, in the cab, and that allows outside pressure to rush in, assisting drivers pressure on the pedal
So you can sometimes hear this air going into the booster
There are filters and a boot that usually muffle this sound, but the sound is a required function on this type of power assist
There can also be a "vacuum release valve" on the cab side of booster, the brake pedal push rod activates this valve as a fail safe for vacuum controlled Cruise Control
If the Cruise control module uses vacuum to hold cruise speed then pressing the brake pedal would dump the vacuum so throttle would close, its a "failsafe" in case cruise module didn't get the "brake light" shut off signal
This vacuum release valve can also make an air noise when pedal is pressed
Not sure what the 2019-2022 Ranger use for cruise control
If "drive-by-wire" is used then no need for a vacuum dump valve, lol
Drive-by-wire means there is no throttle cable, an electric motor moves the throttle plate in response to a gas pedal sensor, so computer could hold a set cruise speed vs needing a separate cruise module and cable
A "clunk" noise from rear when applying the brakes can be mis-adjusted Park Brakes
Power assist brakes use outside air pressure to assist the driver to push down on the pedal
The booster has 2 chambers
Vacuum side gets the negative pressure from engines intake vacuum, so below outside pressure
When you press down on the pedal that opens the atmosphere valve at the base of the brake pedal push rod, in the cab, and that allows outside pressure to rush in, assisting drivers pressure on the pedal
So you can sometimes hear this air going into the booster
There are filters and a boot that usually muffle this sound, but the sound is a required function on this type of power assist
There can also be a "vacuum release valve" on the cab side of booster, the brake pedal push rod activates this valve as a fail safe for vacuum controlled Cruise Control
If the Cruise control module uses vacuum to hold cruise speed then pressing the brake pedal would dump the vacuum so throttle would close, its a "failsafe" in case cruise module didn't get the "brake light" shut off signal
This vacuum release valve can also make an air noise when pedal is pressed
Not sure what the 2019-2022 Ranger use for cruise control
If "drive-by-wire" is used then no need for a vacuum dump valve, lol
Drive-by-wire means there is no throttle cable, an electric motor moves the throttle plate in response to a gas pedal sensor, so computer could hold a set cruise speed vs needing a separate cruise module and cable
A "clunk" noise from rear when applying the brakes can be mis-adjusted Park Brakes
Last edited by RonD; May 5, 2022 at 11:38 AM.
Thread Starter
|
Member
Joined: Dec 2021
Posts: 3
Likes: 0
From: Greenlawn NY
The noise "can be" normal
Power assist brakes use outside air pressure to assist the driver to push down on the pedal
The booster has 2 chambers
Vacuum side gets the negative pressure from engines intake vacuum, so below outside pressure
When you press down on the pedal that opens the atmosphere valve at the base of the brake pedal push rod, in the cab, and that allows outside pressure to rush in, assisting drivers pressure on the pedal
So you can sometimes hear this air going into the booster
There are filters and a boot that usually muffle this sound, but the sound is a required function on this type of power assist
There can also be a "vacuum release valve" on the cab side of booster, the brake pedal push rod activates this valve as a fail safe for vacuum controlled Cruise Control
If the Cruise control module uses vacuum to hold cruise speed then pressing the brake pedal would dump the vacuum so throttle would close, its a "failsafe" in case cruise module didn't get the "brake light" shut off signal
This vacuum release valve can also make an air noise when pedal is pressed
Not sure what the 2019-2022 Ranger use for cruise control
If "drive-by-wire" is used then no need for a vacuum dump valve, lol
Drive-by-wire means there is no throttle cable, an electric motor moves the throttle plate in response to a gas pedal sensor, so computer could hold a set cruise speed vs needing a separate cruise module and cable
A "clunk" noise from rear when applying the brakes can be mis-adjusted Park Brakes
Power assist brakes use outside air pressure to assist the driver to push down on the pedal
The booster has 2 chambers
Vacuum side gets the negative pressure from engines intake vacuum, so below outside pressure
When you press down on the pedal that opens the atmosphere valve at the base of the brake pedal push rod, in the cab, and that allows outside pressure to rush in, assisting drivers pressure on the pedal
So you can sometimes hear this air going into the booster
There are filters and a boot that usually muffle this sound, but the sound is a required function on this type of power assist
There can also be a "vacuum release valve" on the cab side of booster, the brake pedal push rod activates this valve as a fail safe for vacuum controlled Cruise Control
If the Cruise control module uses vacuum to hold cruise speed then pressing the brake pedal would dump the vacuum so throttle would close, its a "failsafe" in case cruise module didn't get the "brake light" shut off signal
This vacuum release valve can also make an air noise when pedal is pressed
Not sure what the 2019-2022 Ranger use for cruise control
If "drive-by-wire" is used then no need for a vacuum dump valve, lol
Drive-by-wire means there is no throttle cable, an electric motor moves the throttle plate in response to a gas pedal sensor, so computer could hold a set cruise speed vs needing a separate cruise module and cable
A "clunk" noise from rear when applying the brakes can be mis-adjusted Park Brakes
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