Squeeling Noise from Rear Brake

[ub7rm]

After the brakes get warm, particularly if there is a load in the back of the car there is a really high pitched squeel coming from the back passenger side.  Pretty sure its not the bearing as I've tried rocking the wheel and there is no play. 

I suspect the pads aren't retracting back from the pad properly.  Forgot to say this squeel vanishes as soon as I touch the brake pedal or apply the handbrake one notch.

Is it possible the guide pins need lubricating?  Am I right in thinking that its these that allow the pad to back off from the disc once the brake is released?

Guess the other thing could be the caliper itself is a bit sticky?

[Viking]

When did you last have pads replaced and were they genuine ones? The pads have a sticky backing which glues them to the caliper so that they're pulled away from the disc when not in use. If they're still stuck to the caliper then I guess the caliper is sticking or the guide pins etc.

[ub7rm]

Thanks, the pads are genuine ones and were fitted more than 4 years ago.  They are certainly worn but not excessively.  The backing you're speaking of isn't glue as suchits just so you don't have to use copper grease or the like to stop squealing.  When you take your foot of the brake the only thing that pushes the pad away from the disk is the rotation of the disk but if the guides are dirty this can stop them being fully pushed back - as I understand it anyway!

Worst case its the caliper itself which is sticky but the brakes aren't binding on / no excessive brake dust so I think my first port of call will be to lubricate the guides.

[Viking]

Yep, lubricate the guides then.