Jim,
I've already replaced the caliper and got no change. None of the
mounting bolts look too long, the emergancy brake is used regularly and
is snug at about 4 clicks. The puzzle is that it occurs regularly after
a standard set of highway miles(10-12) and after an interval of 8-10 hrs
(parked during the day or overnight) is absent until the usual distance
is driven. When I replaced the rotors I was surprised at the difficulty
of removing the old versus the ease that this new one seems to almost
fall off the hub. I've attributed this to my failure to release the
parking in the initial replacement and have wondered if I damaged
something in the parking brake mechanism during the rotor removal. The
right side has behaved fine, but I do recall the rotor was easier to
remove. Whether I realized what was making the removal difficult or
merely a difference in the parking brake tightness, who knows. Thanks
for the help.
Neal
[EMAIL PROTECTED] wrote:
In a message dated 5/16/2006 4:53:53 A.M. US Mountain Standard Time,
[EMAIL PROTECTED] writes:
Hello list,
I need some help from your collective wisdom. My problem is strange.
For the last several months I've been dealing with my 1981 3000CD left
rear brake that seems to be either grabbing the rotor or pulsing such
that I hear a hard metal sound as if the pad was loose or the rotor was
moving. It is not smooth, but almost a popping like metal sound. When
applying the brakes the noise quiets, is gone. It starts after a period
of driving, usually I hear it after about 10-12 miles at 50-55.
Sometimes once it quiets is smooths out with the occasional pop. When
this first started I thought it a bad driveaxle and replaced it. A week
or so later the noise returned. I replaced the caliper and there was no
change. I replaced the brake hose and got a week of relief. But it's
back. I don't feel any vibration when moving at highway speeds and
often in stop and go traffic, which I don't do a lot of, the noise
rarely appears. The rotors were replaced in the recent past as was the
master cylinder ( within the last 18 mos to 2 years). When I had my
indie look at it they found the sway bar busings worn and replaced them
but saw nothing else. But since they didn't drive it long enough they
didn't hear the noise. The brakes are firm and I don't feel a pulsing
due to a warped rotor, but something is producing this weird response
and it's getting a bit frustrating. Any help would be appreciated.
Thanks,
Neal
Neal,
Any chance one of the wheel studs is longer than it should be and is
clashing against the internals of the emergency brake? Do you use the emergency
brake often? Maybe it is not releasing the same each time and giving the
intermittent noise you hear.
Barring the above, I think I would spring for a new caliper.
Regards,
Jim Friesen
Phoenix AZ
79 300SD, 262 K miles
98 ML 320, 142 K miles
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