Parking brake beeping at me

[skippyozz]

Hi all,

Sorry if this topic exists elsewhere, search function is down.

Car: C-Klass Estate, late 2004 (facelift)150.000 KMs (nearly 100 000 miles)

Problem symptoms:
Parking brake beeps at me. I can cancel the beeping from steering wheel. Warning light stays on. Need to pull pedal back with my foot. That used to work fine, but not anymore. Pedal drops a bit on its own. The slightest bump on the road sets it off again.
Note: I do need to push the pedal quite far for the brake to hold the car.

Already done:
I opened the hatch under the rear seats, cleaned everything, WD-40'd the cables. Wasn't particularly dirty anyway.
Didn't see any adjustment. All I saw was a big bolt, doesn't move.

Went under the dash (swore a lot), checked & relocated the switch. Switch barely touches the pedal when pedal all the way up (normal?).

Looks as if the pedal come up a bit'weakly'though. The slightest touch to the pedal sets of the warning. Less than 1mm movement triggers it.
Isn't it supposed to adjust automatically?
AQny help would be welcome, thx

[niva441]

It seems to me you've covered the basics and beyond to me. My next guesses would be that either the return spring has weakened (unlikely) or the switch/sensor is out of adjustment or broken.

[skippyozz]

Thx Niva,

Was thinking of getting a new switch. You just touch it and it goes off!

[niva441]

I find the beep insistently annoying enough when it goes off as the brake hasn't released cleanly, so it must be a complete sod when doing it of it's own accord.