Extreme Cold: Brake system noise while not in motion

[usererror]

Folks,

 

We've had some very very cold weather here in Northern Michigan.

 

On days when the temps are 10* and below, when I get in the car for the first time, start the car, and push the brake pedal, I hear a strange noise. It sounds like what the ABS would sound like when it's engaging because of slipping on ice. But I am not even moving. I'm still in Park. I haven't yet tried to record this sound, but has any else had this experience?

 

When you start driving the brakes all appear to be working correctly but something is not liking the extreme cold.

 

Before I try to schedule a dealer visit, I thought I'd ask here. The wheels and brakes are free from snow and ice, too. Scheduling a dealer visit for me can be a challenge since I'm on the road Mon-Fri usually out of town for work.

 

Thanks!

[GrySql]

Stepping on the brake pedal while stopped can cause a buzzing sound in the engine bay caused by the electric brake pump, this happens in any weather.

I hear it when the car is in the garage every time I back out, outdoors it's not so noticeable.

If it's not that then a trip to the dealer might be needed.

[FordService]

Folks,

 

We've had some very very cold weather here in Northern Michigan.

 

On days when the temps are 10* and below, when I get in the car for the first time, start the car, and push the brake pedal, I hear a strange noise. It sounds like what the ABS would sound like when it's engaging because of slipping on ice. But I am not even moving. I'm still in Park. I haven't yet tried to record this sound, but has any else had this experience?

 

When you start driving the brakes all appear to be working correctly but something is not liking the extreme cold.

 

Before I try to schedule a dealer visit, I thought I'd ask here. The wheels and brakes are free from snow and ice, too. Scheduling a dealer visit for me can be a challenge since I'm on the road Mon-Fri usually out of town for work.

 

Thanks!

HI usererror,

 

Once you have an appointment set up, please let me know so I can see how I can best assist. :)

 

Meagan

[Texasota]

I also reguarly hear the exact same sound that GrySql described. This noise is especially noticeable while creeping up to a parking curb (i.e. creep and brake, creep and brake...). I interpret this noise as completely normal given the many discussions about it on this forum.

[usererror]

I also reguarly hear the exact same sound that GrySql described. This noise is especially noticeable while creeping up to a parking curb (i.e. creep and brake, creep and brake...). I interpret this noise as completely normal given the many discussions about it on this forum.

 

But mine happens when the car is in PARK. It does not do this while in PARK when it's not cold. If I also leave my foot applying the brake it will make the noise then stop, then make the noise again. I'll try to get a recording of it. It is very loud.

[GrySql]

 

But mine happens when the car is in PARK. It does not do this while in PARK when it's not cold. If I also leave my foot applying the brake it will make the noise then stop, then make the noise again. I'll try to get a recording of it. It is very loud.

It can happen in PARK as well, as long as you are pressing the brake pedal the electric motor can start buzzing. It may happen without touching the brake pedal if the hydraulic pressure is too low.

It may stop and start as the hydraulic upper pressure limit is reached, then cycle again when the pressure hits the lower limit. It's a pump that keeps the pressure between the high and low limits of the system.

 

If your noise is much more that the normal buzzing and only happens when a certain environmental temperature is reached then I'd suggest you visit a Dealer to let them investigate your concerns.

Let Meagan, our Ford Rep, help you with the Dealer visit as she suggests in Post #3.

Edited February 28, 2015 by GrySql

[lolder]

I think it's an electric pump that provides vacuum to the hydraulic brake booster chamber if the ICE is not running or the vacuum is too low. The noise is probably normal.

[GrySql]

I think it's an electric pump that provides vacuum to the hydraulic brake booster chamber if the ICE is not running or the vacuum is too low. The noise is probably normal.

You may be right, I stand corrected.

There are two brake pumps, the Brake Booster Vacuum Pump and the Hydraulic Control Unit (HCU).

The Vacuum Pump makes the most normal noise, the Workbook calls for replacement of the Vacuum Pump or the VP Isolators if the sound exceeds 70dB.

 

--

Brake Booster Vacuum Pump

The brake booster vacuum pump is a single speed electric motor pump used to supply additional vacuum to the brake booster to enhance brake system performance.

Vacuum Pump Relay

The ABS module uses 2 standard mechanical relays to activate the vacuum pump. The relays are connected to the pump in parallel and only one relay is used at a time to activate the vacuum pump.

--

Hydraulic Control Unit (HCU)

The HCU contains the solenoid valves, the hydraulic pump motor and the pressure sensor used by the ABS for the various stability control systems. The ABS module and the HCU are attached directly together and are serviced as an assembly.

[hybridbear]

Check out these three threads. There are a variety of situations where you'll hear this buzzing.

http://fordfusionhybridforum.com/topic/6346-shutters-buzzing-or-something-else/

http://fordfusionhybridforum.com/topic/7325-loud-buzzing-noise-when-opening-the-door-andor-first-turning-on/

http://fordfusionhybridforum.com/topic/8645-got-active-grille-shutters-buzzinghumming-sound-when-switched-off/

[FordService]

 

Let Meagan, our Ford Rep, help you with the Dealer visit as she suggests in Post #3.

Thanks for the shout-out! :)

 

Meagan

[usererror]

Thanks everyone. Of course NOW that I'm back from being gone for a few weeks for work, Michigan is suddenly not in an icebox situation, so everything is sounding normal now. I may have to now wait until next winter for this to happen again. Unless everything is still just 'breaking in'. It's only been 4 months since I got the FFH.