Whistling noise

Maintenance/Repairs
,
1

I get a whistling (not squeaking)noise when I step on my brakes at above 40 MPH. The noise is very low , if at all below that. Is that a leak in the master cylinder, etc?

Thanks

2

Not the master cylinder, but a leak in the vacuum brake booster or the brake booster check valve. Those should be checked out first.

Tester

3

Thanks. I will check that out.