l494 Screeching sound when pressing the brake pedal

[Naks]

Hi all,

This happened twice in two days, after starting the car the first time in the day (ambient +-34C).

Video:

It doesn't happen after driving around and then starting the car again.

I went past my mech yesterday, and he tightened the bolts on the brake booster. They were not loose, but there was some give in them.

Funnily enough, I saw the replies to my question on another two forums, and got similar feedback. Someone posted this TSB, which affects the booster, it may be helpful to others: https://www.rrsport.co.uk/gallery/albums/userpics/23569/SB-10106336-9340.pdf

"Reference: SSM72903
Models: Range Rover/ L405 Range Rover Sport/ L494
Title: Air Leak Noise When Brake Pedal Is Pressed
Category: Chassis
Last modified: 29-Jul-2016 00:00:00
Symptom: 301000 Service Brake System
Attachments: D7u Booster Fixings Secure Sequence.pdf (D7u Booster Fixings Secure Sequence.pdf)

Content
Issue:
Air-leak noise when brake pedal is pressed.

Cause:
Low or high clamp load on brake servo fixings.

Action:
If an air-leak noise is exhibited during brake pedal depression, then slacken the 4 fixings off and re-torque to 24Nm. Ensure when torquing you follow the pattern detailed in the
attachment.

Re-apply the torque (following the attached pattern) a second time 30 minutes later to ensure the fixings have not relaxed.

If the noise is still present then please progress with replacement of the component."