Tech Forum : E21 323 rear disc brake question

BarryA	Posted Wednesday, May 2nd 7:05pm [Edit] [Quote] [IMS] [View car]
Member Post nr. 185 Sacramento CA 81 320	Just finished a complete rehab on a pair of post-facelift 323 trailing arms and disc brakes, and installed the completed assemblies on a US spec ’81 320. All "wear" items were replaced with new parts(rotors, e-brake shoes, springs & cables, stub axle bearings & seals, caliper kits & pads, stainless hoses) along with the suspension pivot bushings and backing plates. Brakes work great – smooth and linear – but there’s a very noticeable rattle in the rear calipers (sliding section rattling against the carrier that’s bolted to the trailing arm) on rough pavement. The calipers (and everything else) had a fair amount of surface rust when acquired, so everything was bead-blasted clean and painted before assembly. Before being cleaned up, the calipers didn’t slide smoothly in their carriers – now they move easily, but there seems be a lot of clearance between the carrier and caliper body. Doesn’t look like there’s anything missing in the way of spacers or guides that should go between the calipers and carriers, and the big “U” shaped springs that tension the calipers against the guides aren’t bent and press the calipers against the carriers. Checked the parts diagram on Real OEM, but it only shows the caliper and related parts, not the carrier, and there’s nothing in the parts list that sounds like a spacer or guide. Can anyone who has experience with 323 calipers shed any light on this situation, or is a rattle in the calipers just part of price paid for having 4 wheel discs? It’s hard to believe the calipers rattled like this when 323s were new…..

sunbeam***	Posted Thursday, May 3rd 12:07am [Edit] [Quote] [IMS] [View car]
Member Post nr. 292 wirral UK 1982 323i	Had exactlty the same problem, the rattle had me guessing for over a week. Remove the pads and slide the caliper out of the carriers, the spring in the carriers needs to be bent back to the rear of the car by a good inch so it puts some decent tension on the caliper,reassemble and you won't hear a thing.