New PGD394QS front pads-clanking? '95 525iT

[Rob Edwards]

I put a new pair of Raybestos pads and new Brembo OEM rotors on the wagon two weekends ago to replace the Metalmasters I put on 45,000 miles ago (now at 117K). No problem with the change, and I bedded them in by a bunch of hard 30-0 and 45-0 stops. All seemed well. Now when I get brake at moderate speeds, Im getting a clanking/shuddering noise from both fronts that is more pronounced the harder the pedal application. The metal masters never did this under braking, though there would be a small clunk when pulling out of the garage in reverse- this I figured was just the pads moving slightly in the carriers.
I pulled the front wheels, retorqued the caliper pins and carrier bolts, everything seems fine, the pads are seated in the carriers. Wheel bearings are original, but there was no free play in them when I pulled around on them. But there's still this clanking.
The pads seem to fit the carriers just fine, but I'm wondering whether I got the incorrect size pads, but the PartsAmerica site lists the PGD394QS as being correct: http://www.partsamerica.com/ProductDetail.aspx?mfrcode=RAY&mfrpartnumber=PGD394QS&parttype=219&ptset=A The Braking is fine, but the clanking's gotta go!

Anyone had this experience?

[zmuff]

I'm using the same pads on my car with no issues at all, PGD394QS on the front, PDG396QS on the rear. Also have Brembo OEM rotors all the way around. You have the right brake parts, is it possible that your upper and lower control arms need attention?

[Rob Edwards]

I changed the UCA's and LCA's with lemforders 3 years and 20K miles ago, torqued them on the ground. I suppose it's possible, but I didn't have the 55 mph shimmy before I did the brakes, nor do I have it now. Good thought, though. Glad to hear someone else has no problems with these pads (How many sets has Bill R put on without complaints :p )

[joshua43214]

If none of the other obviouse stuff turns up as a problem, check this. the mount can wear in the circled area in the picture and allow the pad to slide up and down with the rotor making a bang or clunk sound. remove the caliper and make sure the pad can't move in the mount. If it can, remove the pad a lay it on a hard surface. the take a prick punch and hammer it near the edge of the backing plate to swedge the metal outwards and make the backing plate slightly longer. make sure you only swedge one end of the pad that will not take any load under forward braking. File it back if you go to far.

[632 Regal]

the QS require NO bedding procedure. Is the anti-rattle clip still on and tight? As mentioned check the carrier for wear. Did you clean the piston backs and apply the synthetic grease as directed? If your getting shuddering you probably warped the rotors from doing the unnessary bed in procedure...been there done that.

edit: those are the correct pads.

[Bill R.]

100 sets of them on without complaint now. Most of these weren't on bmw but that shouldn't matter. The complaint ratio i get doesn't seem to matter what the make of vehicle is.



I changed the UCA's and LCA's with lemforders 3 years and 20K miles ago, torqued them on the ground. I suppose it's possible, but I didn't have the 55 mph shimmy before I did the brakes, nor do I have it now. Good thought, though. Glad to hear someone else has no problems with these pads (How many sets has Bill R put on without complaints :p )

[rizal]

the QS require NO bedding procedure. Is the anti-rattle clip still on and tight? As mentioned check the carrier for wear. Did you clean the piston backs and apply the synthetic grease as directed? If your getting shuddering you probably warped the rotors from doing the unnessary bed in procedure...been there done that.

edit: those are the correct pads.
Check that the shims haven't come off the pads. I put Raybestos QS pads on my wife's Toyota Sienna and 6,000 miles later it developed a sound like a really loud wear indicator that doesn't silence with brake application. All four front pads lost at least one of the pins (three per pad) that hold the shim onto the pad. The shim creating the noise had lost all three and slid down against the rotor. Pure garbage. I'll never again buy Raybestos nor any pad with riveted on shims. Just my experience...glad that so moany others love these pads.