Whistle in SH brakes

[Ratbag]

Gidday All

SWMBO's SH has just developed a high-pitched whistle (like a tuning fork sound ... ) when braking.

It isn't the grinding sort of noise that comes from the brake pad warning "finger", or the pad backing plate hitting the disc rotor ... .

There is no feeling of roughness when braking, and the noise vanishes if braking a little harder than just normally and gently.

Happens with the VDC on and off.

No sign of any roughness on the outside of the disc rotors.

I haven't had a good look yet, as don't want to burn myself on the discs ...

Anyone got any ideas as to what it could be?

TIA. RB.

 

[Ratbag]

Just had a look at both D/S brakes. No sign of anything odd.

Could just be fine dust under the pads.

ANY suggestions welcome ...

 

[NachaLuva]

A high pitched "squeal"?

Could be several things...oil contamination in the brake pad, pads glazed, even the angle at which the pad wears can make brakes squeal slighlty. A bit of gravel, etc caught in the backing plate can do this too. I had this on one trip, was a bit of a bugger to clear (thx Bennie )

If you're up to it, you could take out the pads & inspect them. Maybe use some fine sandpaper to remove glazing, not sure bout contamination...

 

[Ratbag]

Gidday NL

A high pitched squeal?

Not really a "squeal" either. More like a high-pitched "siss" noise. I have never heard it before, and every car I have owned since my first Morris 1100 (1964) has had disk brakes (except my '68 LC, of course - drums all round with 8 leading shoes ... ).

Could be several things...oil contamination in the brake pad, pads glazed, even the angle at which the pad wears can make brakes squeal slightly. A bit of gravel, etc caught in the backing plate can do this too. I had this on one trip, was a bit of a bugger to clear (thx Bennie )

If you're up to it, you could take out the pads & inspect them. Maybe use some fine sandpaper to remove glazing, not sure bout contamination...

I couldn't see behind the backing plate (of course). If it's this, it may clear by itself after a few days. Otherwise, I'll just drop the rotors off and have a look.

No signs of oil anywhere )). Doesn't sound like anything as large as even fine sand particle size (that makes a nasty grinding noise that gets worse the harder one brakes ... ) - this noise goes away with even slightly harder braking than very gentle ...

I've never experienced any kind of glazing with any of my cars. Certainly not with Roo1. The rotors look nice and evenly smooth, so perfectly normal (a bit better condition than the ones in Roo2, but even they aren't worn to the point of any noticeable lipping at the outer or inner edges).

Even when one of our Colts was missing the anti-squeal shims altogether, the brakes didn't make any kind of protest!

I am rather partial to the very fine dust theory ATM, but could be easily persuaded otherwise if anyone else has ever had the same kind of noise, and discovered what it was.

Thanks for your reply and suggestions. All grist for the mill ...

 

[NachaLuva]

If its something caught in the backing plate, try rocking the car in 1st then reverse...it "may" clear it. Had to do that one time too....amazing what going fast through bog holes can do! I go slow now lol

 

[Ratbag]

Good thinking, NL.

It doesn't sound like this, because it disappears completely with even moderate braking.

That having been said, judging from the avalanche of replies to my question, it also doesn't seem to be any of the usual suspects that are causing it to occur.

I reckon that it will probably just go away all by itself over a couple of days. Either that, or develop into something that is easily recognisable ... I hope it's not the latter!

Roo2 goes in for its exhaust repair tomorrow ...

 

[Ratbag]

Now there's an interesting thing ...

SWMBO has been out in RonnyRoo all day (not many kms), but the mystery noise has now magically vanished ...

I am always very twitchy for the first year or so with s/h cars. After all, looks can be deceptive, and the apparently most well cared for car can still have hidden problems. Takes a heck of a lot to make up the $20K difference in price from new though ...

Speaking of which, NL. How is your niece's Forester going? Well I hope.

 

[NachaLuva]

Now there's an interesting thing ...

SWMBO has been out in RonnyRoo all day (not many kms), but the mystery noise has now magically vanished ...

Good to hear :biggrin:

Speaking of which, NL. How is your niece's Forester going? Well I hope.

Yeah good thx. ATM she's up in NSW collecting skinks for a survey she's doing. She said she hasnt made any drop their tails...yet :lol:

 

[Ratbag]

Glad to hear that, mate.

Always a very big responsibility when others look to one for this sort of advice.

We were in the same position recently, when a friend bought an SH Fox X as a result of our experiences with Subarus. Fortunately, she is absolutely thrilled with her new baby too.

One always wants to help one's friends and rellies, but it can be fraught at times!