Help needed... strange reaction

[Adam230K]

Ok so when I reverse I get what sounds like a REALLY LOUD 'horn' sound from the rear, and its continuous and only happens in reverse.

On the motorway, it sounds as if i have a bad wheel bearing too, the loud humming noise coming form the rear.

But then... today I noticed something very strange... as I was reversing and trying to find out what the hell it is, i thought let me try and lightly touch the brakes while the car is still reversing... i get a loud thud, almost like a jolt, and the horn noise stops instantly. If I stop the car and start reversing again, the horn noise will start again... til i touch the brakes (very lightly), this jolt will then occur accompanied by a 'thud' sound and the horn will stop.

I've had my rear pads out and cleaned etc because there was an accumlation of rust around the callipers... but this can't be it, can it?

 

[Sp!ke]

I had that on the Volvo, turned out the handbrake pad liner had separated from the shoe itself.

 

[GP801]

Depending on the car it might be the parking brale shoes inside the rear hub. Often neglected. Our 124 started making a dreadful noise soon after we got it. The pads had quite literally disintegrated. Not sure why this should only be in reverse though.

 

[GP801]

Snap!

 

[Adam230K]

So just gotta replace pads then? should I do the discs aswell?

 

[Whitey]

^ inside the drum part of the disc iirc

 

[Merc Owner 2B]

The parking brake pads, if that's the cause, have nothing to do with the discs, calipers and pads. It is a seperate device.

What car do you have?

 

[BlackC55]

Is this on the Polo?

Check the trailing arm bushes.

 

[Dieselman]

It will be that the pads need retaining clips installing, a known fault on all VAG cars.

 

[Adam230K]

Its the VW Polo. You think the trailing arm bushes are responsible for the clunk Olly? are these basically like the wishbone bushes but for the rear, near the the rear wheel on each side right?

And that nasty horn-like sound is definitely the brakes inside the disc drum rubbing then? it also squeaks from the rear every time i try to stop.

2 separate issues eh?

 

[Adam230K]

More food for thought... on the way in this morning... motorway, I can hear a constant whirring noise coming from the back, almost like the wheel bearing is worn...

But when i jacked up the car on either side and tried to spin the wheels, one was absolutely fine, the other was slightly stiff but still rolled, and no noise at all. What I found strange was, when i span both rear wheels, i could hear a very faint rubbing sound, as if the pads were touching the discs... not sure if thats normal?

Any help is much appreciate... just want to be sure before i start buying and replacing things