Car rolled in PARK

[drollie]

Has anybody heard of this, please?
I halted on sloping ground, put the car in park, assumed that the handbrake engaged (03MY) and pressed the boot release on the dash. I got out with the engine still running, but the boot hadn't unlatched. So I reached in through the open driver's window and tried the dash release again, still no joy...
THEN I switched the engine off and the car immediately rolled backwards - still in PARK and without touching the handbrake!
I'm baffled. Is this a case of brake AND transmission faults happening at once? Or is there something else that I'm missing?
Any thoughts, please?
Ollie

[mike020150]

If the gear lever was placed correctly in 'Park', the car could not roll backwards (other than a few inches at most) because the gearbox is physically locked to prevent movement. Therefore, the possible options are: A) the lever didn't move far enough to engage the 'Park' position; B) wear in the lever linkage meant that 'Park' wasn't actually engaged inside the gearbox; C) damage inside the gearbox prevented engagement. Wear in the linkage is not uncommon which suggests that a check of the components would be a good first checking exercise.
As far as I am aware, the handbrake on a car of this age does not apply itself automatically when the car comes to a halt. It is only applied automatically when the key is removed from the ignition switch. Unless you moved the handbrake switch to the 'on' position before exiting the car, the handbrake would not have been in operation. Switching the ignition off, without removing the key, the handbrake would have remained in the 'off' position, allowing the car to roll backwards if 'park' was not engaged. Mike.

[jpgardnerieng132]

I've had no "park" problem with my XF but had a similar problem with the electric parking brake due to a duff battery. During lockdown so I kept the battery charged in between runs until I was able to have it renewed, no problem thereafter.