e36 new brake pads are clinking

[Ron Katona <ron3b@xxxxxxxx>]

Carl Scholz wrote:
> I just replaced the front pads and rotors on my '93 325is for the first
> time in my ownership.  The old pads were stock, the new pads are Hawk
> HP-Plus.  The new rotors are OEM.
> 
> There is an unpleasant sounding clink, clink, clink that goes with the
> wheel rotation when coasting slowly.  As soon as the brakes are even
> slightly applied, it stops (and it starts squealing, but that I can
> live with).
> 
> My question: the stock pads had that spring on the back of the inner one
> (round 3 pronged that fits into the caliper piston hollow).  The new
> pads had no such springs.  I just put them in dry.  Is the clinking
> related to the possibly loose pad?  Will the gummi-fledge (whatever it's
> called) help?  Should I pull the backing springs off the old pads and
> somehow try to use them?  How?

The HP Plus is advertised as a Street/Track pad, but unless you want to
live with the rattling and squealing you'll want to choose another pad
for the street. For the track, these will probably be fine unless you're
really moving or are hard on the brakes. In that case go to the Blues. A
"Street/Track" pad means is not optimal for either.

Track pads with no spring clips will rattle and squeal like crazy. The
fact that the "clicking" is rhythmic and not just random rattling
suggests that you have a warped rotor. Each revolution of the wheel at
slow speed is picking up the pad and then dropping it as it hits a high
spot. You've indicated you have new rotors - have them checked for
runout. I recently warped a rotor and with track pads on I get this same
"clicking" on the side with the warped rotor as well as the usual
rattling of the track pads over bumps and stuff at all four corners.

I suppose the anti-squeal compound sold at BMW dealerships might help,
but it would just cure the symptom, not the cause. You have a pad that
is going to make noise on the street because it doesn't have the clips.
You may also have a bad rotor. Those are your real problems.

None of this should prevent you from running at the track unless the
rotor is so warped that at high speed you're getting a lot of vibration
from the brakes.

In any case, the anti-squeal compound is called "BMW plastilube." Part #
81 22 9 407 103 - $2.78 each. Get it at the dealer with your BMW CCA
discount. You'll need 2-3 packages for a complete brake job.
- -- 
Ron Katona

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