Rear wheel squeal

[Dark Eyes]

I have a 2006 Jazz Sport Auto, that I leave parked up with the handbrake off to stop the brake pads sticking to the discs. Today, I drove about 30 miles, mainly on the motorway, at 70mph or below. However, when I was back driving at 30mph or less, I could hear a rubbing sound from the back, and when I was reversing there was a horrendous squealing noise!
Has anybody experienced this before?
Does this sound like a stuck piston or a failed wheel bearing?

[sparky Paul]

I would plump for a sticking caliper piston or handbrake mechanism, have a feel of the two back wheels after a run to see if one is warmer than the other.

Using the handbrake sparingly can encourage the handbrake mechanism, particularly the external shaft, to seize and not allow the pads to retract when the handbrake is released. Chock wheels, release the handbrake and make sure the handbrake levers on both calipers are fully retracted. If you detect some movement as you push it against the stop, it is not releasing fully.

[Rory]

On daughter's one of the inner rear pads had worn away and the noise was the acoustic wear indicator.   I'd never heard the noise they make before - when the car is moving at a reasonable speed I'd describe it as more of a ringing noise than anything else.

[culzean]

Acoustic wear indicator is supposed to alert you when pad material gets below 1.6 mm - it is a loud ringing squeal that can easily be heard in the car. A springy stainless steel strip rubs on the face of the disc, you can see it when you look at new pads - it is rivetted to backing plate and hangs down side of pad material.  Either that or you have a bit of road gravel stuck between pad and disc, I had it once and the noise fair set your teeth on edge.....

[Dark Eyes]

I would plump for a sticking caliper piston or handbrake mechanism, have a feel of the two back wheels after a run to see if one is warmer than the other.
Using the handbrake sparingly can encourage the handbrake mechanism, particularly the external shaft, to seize and not allow the pads to retract when the handbrake is released. Chock wheels

I suspect that as the squealing noise is only present when I reverse, that a stuck caliper or mechanism is the more likely.
Do you mean that Using the handbrake, can make this problem, more or less likely to occur?

[sparky Paul]

I suspect that as the squealing noise is only present when I reverse, that a stuck caliper or mechanism is the more likely.
Do you mean that Using the handbrake, can make this problem, more or less likely to occur?

If it is the handbrake lever shaft, rather than the caliper piston, the outer dust seal starts to fail on the shaft, damp gets in and hence corrosion. Regular use of the handbrake can help keep the seizing at bay. It was a constant battle with the old Ford Galaxy we had which used a similar arrangement, eventually the only answer is a replacement caliper due to wear in the shaft.

Sticking caliper pistons are not unusual on the Jazz, as well as pads sticking in the carriers. Strip the brakes down first and check all the basic stuff, pad condition, pads are not tight, caliper slides are free, etc.. Then think about pistons.

[culzean]

I suspect that as the squealing noise is only present when I reverse, that a stuck caliper or mechanism is the more likely.
Do you mean that Using the handbrake, can make this problem, more or less likely to occur?

If it is the handbrake lever shaft, rather than the caliper piston, the outer dust seal starts to fail on the shaft, damp gets in and hence corrosion. Regular use of the handbrake can help keep the seizing at bay. It was a constant battle with the old Ford Galaxy we had which used a similar arrangement, eventually the only answer is a replacement caliper due to wear in the shaft.

Sticking caliper pistons are not unusual on the Jazz, as well as pads sticking in the carriers. Strip the brakes down first and check all the basic stuff, pad condition, pads are not tight, caliper slides are free, etc.. Then think about pistons.

From experience sticking pistons can be caused by leaving brake fluid in too long, it absorbs water and corrosion sets in,  have to say though I have never had a piston problem on a Jazz.  Whenever I take wheels on and off - whether to change wheels winter / summer or look at brakes I always get my trusty tin of motorbike chain lube out - ( I use it on my motorbike anyway so always have some around ) and always give special attention to rear brakes - I will pull gaiter back and spray into cable, spray the spring and where the end cable latches onto mechanism of handbrake - also any hose or vulnerable bit of brake pipe and over the plugs that ABS uses ( modern chain lubes and waxes are rubber / plastic friendly due to 'O' and 'X' ring chains used these days ).  Chain lube goes on thin and will initially penetrate into small cracks but as the solvents evaporate it dries into a tenacious sticky film ( it has to resist being flung off a chain ) and is ideal for purpose.   Spray any exposed threads and brake pipe unions / joints as well - will prevent corrosion and if they ever need taking apart it could make a huge difference.

Rear brakes on cars,  especially discs brakes get a hard life as all the spray and crud thrown up by front wheels gets plastered onto them - I notice Ford, Seat and some Kia models still have rear drums which are pretty much maintenance free compared with rear discs.

[Dark Eyes]

Just to follow up, in case anybody else has a similar problem, it turned out to be the the acoustic brake pad wear indicator; having looked at it closely in action, with the wheel off, I understand the noises now, but it can be confusing, if you don't know what it is IMO.
This is good example of what I experienced, although it did start off being quieter and intermittent, presumably as I was just reaching the limit that it engaged with the disc