Parking Brake Auto-Release Problem

[Ozz]

Greetings,
I've recently noticed that not only does the Auto-Release for my parking brake work when I shift into Drive, I can hear it 'releasing' as I drive. It usually occurs after I have transitioned from cruise to light acceleration and then let off the gas. At that time I hear the 'click' under the dash near the parking brake - sounds identical to the automatic parking brake release.

Has anyone had this problem and if so, what do I need to do to fix it?

FYI - I have 112k miles and have never changed my parking brake shoes - but I don't use the parking brake either...

THANKS!!!

[Blackened300a]

I have that, I traced it down to the pedal bouncing a little bit when I released the cruise. I have a aftermarket throttle body, so there is more tension on the cable when I turn the cruise off so it pops up harder and makes that click noise like you are describing.
If your auto release isn't working then either your shift linkage is out of adjustment just enough that its not hitting the vacuum switch that's located on the right side of the shifter, or the valve is bad. Its a white plastic piece with a vacuum line attached to it that's bolted just under the top plastic half of the console. With the car running, you should be able to shift it from park into drive and hear the slight release of air if its working.

[Ozz]

Thanks for the reply.

Yes the auto release does work when I put the car in drive. My problem is that the noise it makes when it actuates not only happens when I put it in drive but also while driving. Usually when I let off the gas after accelerating lightly.
I guess there is a vacuum actuated 'motor' down by the parking brake. I might just unhook it and hook the vacuum line to a vacuum gauge to see if it's getting the vacuum it's supposed to. I think it needs 10 inHg to stay actuated. Maybe I have a small leak and the vacuum is dropping too low or something - which results in it re-actuating when I let off the gas (higher vacuum).

I am not using cruise when this happens so it's not that in my case...

Anyone else had this problem?

Thanks!

[fastblackmerc]

Thanks for the reply.

Yes the auto release does work when I put the car in drive. My problem is that the noise it makes when it actuates not only happens when I put it in drive but also while driving. Usually when I let off the gas after accelerating lightly.
I guess there is a vacuum actuated 'motor' down by the parking brake. I might just unhook it and hook the vacuum line to a vacuum gauge to see if it's getting the vacuum it's supposed to. I think it needs 10 inHg to stay actuated. Maybe I have a small leak and the vacuum is dropping too low or something - which results in it re-actuating when I let off the gas (higher vacuum).

I am not using cruise when this happens so it's not that in my case...

Anyone else had this problem?

Thanks!
I believe there is only vacuum to the motor when you shift into reverse. There should be no vacuum when driving.

[Ozz]

I believe there is only vacuum to the motor when you shift into reverse. There should be no vacuum when driving.

I'm lucky in that I have access to Ford service manuals online and in parking brake diagnosis section it says:
- block the wheels
- start engine
- push brake
- shift into D
- check vacuum at the parking brake release control motor
- IS VACUUM 34 kPa (10 in-hg)?

If yes, install new parking brake release control motor.
If no, check parking brake release switch.

So I take this to tell me that there should be at least 10 in-hg at the parking brake release control motor (on the pedal assembly) when in drive and that if there is not 10 in-hg then the release switch (on the shifter assembly I think) needs to be checked.

I have accidentially actuated the parking brake and then tried to back out of my driveway. It isn't easy. Once I shifted to D, the release kicked in. This all tells me that the release motor is actuated any time the car is in drive and stays actuated until you shift to neutral (edit: it makes a noise when it goes into neutral from drive also).

Thanks.