[rudy691]

hi guys.

i have a 1999 scenic

and the problem is a whistling noise (on the drivers side i think) when going straight or slightly turning right. when i do a full turn it doesnt whistle at all. it also stops whistling when im breaking.

has anyone got any idea what this could be ?

thanks in advance

 

[Ralph]

Sticking brake pads maybe, take the pads out and clean them and the calipers make sure the pistons are not partly stuck.

 

[rudy691]

the other thing is - it doesnt start straight away. when I leave for work in the morning, there's no noise for about 15 minutes of driving and brake using - then it starts.

I read something on a different forum about servo ? this can't be it, can it ?

 

[Ralph]

Next time you drive it a few miles when you stop see if any of the brakes are hot they will be warm but see if any are noticeably hotter than the others, I doubt it being the servo as it would likely make a noise if you were moving or not, and be careful if one is sticking it may be very hot as in skin removing hot.
My Clio made a whistling noise but only at 40 plus mph it tuned out to be the door mirror not seated properly

 

[Metaal]

It seems to be the filter of the servo accoring to Ronnie wonder
Info from video:
"Iv had a problem with the servo on my Renault megane scenic 1.4 (51 plate).
Every time i applied the brake air would constantly draw in from around the rubber bellow, making some crazy sounds similar to a train horn.

I searched the net only to find that people recommended i needed a new servo,
£600 +, i done all the tests to establish that the servo was operating correctly, which it was.
I then took it to my local dealers where it was confirmed that the servo was working correctly but would need to come in for further investigation regarding the high pitched squeal (££££££ not an option).

After hours of research and staring at diagrams to work out how the servo even worked i basically gave up until today when i had a closer look.
It turned out that the sponge filter visible inside the rubber bellow was blocked with dust and other bits of particles that it had been forced to suck in over the years, i gently worked a pin through the sponge to increase its air flow and 'het presto' no more squeals and hissing.

In conclusion; The servo is designed to draw air in through this filter, but as it was blocked the air was unable to pass through the foam so took its easiest route which was between the side of the rubber bellow and the servo unit, causing the nasty noises.
I do plan to change this filter at some stage, probably for a piece of standard sponge, but im well chuffed that my possible £600 + bill is no more

Im still not 1000000% sure when the servo should be drawing in air, so any input would be appreciated.

Cleaning the filter on top might do the trick else you might have to replace the rubber ring/filter"