Sticking Brakes

[Blueborin]

Hi,
I have a 2007 2.7 Turbo Diesel (Genuine 29K miles). When I apply the brake pedal as normal it feels spongy and sticks and brings the car to a halt on it's own. When I press the pedal sharply it releases the brakes. Also when driving with cruise control the fault can on occasions cancel the function.
I had the brake servo and pedal (switch/sensor) replaced at 24k miles. This has started after lockdown, and I think could be due to it being idle for some lengthy periods. Any advice would be most welcome as a MOT is due soon.

[jeff1954]

Touching the brake pedal whilst in cruise mode will disconnect the function. Regarding the main issue you have the first thing I would do is remove the relevant panels and give everything a spray with WD 40 or the like If no joy with that I might be a problem with the master cylinder.

Jeff

[Blueborin]

Thanks Jeff, will give it a try. The cruise sometimes cancels when the brake pedal hasn't been pressed. It would seem that somehow the discs/brakes are somehow catching or applying remotely which subsequently disengages the the cruise. The car goes in for a check on Weds so it will be very interesting to see what comes out from the fault codes.
Robin

[Blueborin]

Problem sorted.
Caused by a faulty replacement brake servo. Apparently when you have the brake servo replaced you should also replace the master cylinder. Its a known problem with the S-Type. Both parts now replaced with genuine jaguar parts with a 2yr warranty.

[steve_m]

Are the brakes a known issue on the S Type?
Set off this morning and had a worrying lack of retardation after the first 50 yards to the junction, seemed ok after that though.