Technical JTD130 Rear disc brake squeal

[Rustymini]

The rear discs on my jtd130 have started to squeal on 'soft' braking. If I hit the brakes hard I don't get a squeal (except from my wife), but under normal braking it's loud and getting worse.
For it's last MOT 2 months ago it failed on braking effect on the rears which was traced to a sticking caliper. The brakes were stripped down, freed up, and copper lubed and everything declared OK.
What else could be causing the squeal? Are there any anti squeal shims available?
Has anyone else had the same problems?
Any info would be very welcome.

 

[werdna]

I have just done my weekend and the squeal was caused by not having any brake pad left !!! just the metal rubbing on the disc. If I was you I would have a quick check of the pads first.

 

[mountainmachine]

Think of it like a needle on a record player, when you press the brakes lightly there squealing because either (the wear indicator is touching the discs, or bare metal is touching the discs, or a stone is trapped touching the discs) acting like the needle. But when you break hard this is negated as the obtrusion is pressed into the disc. Do you feel a very slight judder?

I'd check your pads, and discs, as you may have scoring.