S40 (New) Brakes : Incessant rattling!

[RollingThunder]

I think I know the answer to this one, but before I spend any money I wanted to sanity check my thoughts with you... thanks for humouring me

Since buying my 2008 MY S40 D5 a month ago, it has had a rattle under the back end. I thought it was an exhaust heatshield, maybe an exhaust baffle, however the noise went away as soon as I touched the brakes - so that would seem to point to the anti-rattle shims in the rear brakes?

I put the car up on ramps at the weekend and couldn't find anything loose that could account for the noise, so I took the wheels off -and everything seems ok. The caliper springs are in place and providing tension etc, the pads aren't loose fitting (the handbrake was off!), and the calipers etc are securely mounted. So all seems well, but I am still tempted to replace the pads, because I didn't remove them to inspect them (time constraints) so they may still be missing the 'prongs' that fit into the pistons?

I couldn't think of anything else that would cause the rattle, especially with it ceasing as soon as I touched the brake pedal...

Am I missing anything that you can think of?

Many thanks
RT

[T5R92011]

Could be rear shock mounts.

[iainmd]

Almost guaranteed to be the brake pads rattling in the caliper. I have had this problem myself. Early S40/V50 rear pads had a spring on the inner pad that clipped over a groove in the piston to stop the rattling. Later pads had a rubbery shim pad between the caliper and the piston on the inner pad instead.

I fitted a set of EBC pads that had neither and they rattled almost constantly and clanked when I went over speed humps. I tried copperslipping them to death with no joy and after consulting my trusted local garage they were replaced with Volvo OEM (ATE) pads. Result... rattle gone. I never used anything other than Volvo OEM pads on the rear again until I got rid of the car about 8yrs later.

[RollingThunder]

Originally Posted by T5R92011

Could be rear shock mounts.

Thanks T5R92011. I did check these for any play and they seemed fine.

Originally Posted by iainmd

Almost guaranteed to be the brake pads rattling in the caliper. I have had this problem myself. Early S40/V50 rear pads had a spring on the inner pad that clipped over a groove in the piston to stop the rattling. Later pads had a rubbery shim pad between the caliper and the piston on the inner pad instead.

I fitted a set of EBC pads that had neither and they rattled almost constantly and clanked when I went over speed humps. I tried copperslipping them to death with no joy and after consulting my trusted local garage they were replaced with Volvo OEM (ATE) pads. Result... rattle gone. I never used anything other than Volvo OEM pads on the rear again until I got rid of the car about 8yrs later.

Thanks iainmd. Sounds exactly like what is happening with my S40. Looks like I'll need a set of OEM pads - the ones fitted at the moment are Bosch.

Thanks to you both, very helpful as always