Diagnose and repair
difficult brake issues
It’s easy to get complacent with routine repairs, but there are
always going to be unique circumstances that come up.
By Barry Hoyland, Contributing Editor
Every once in a while,
58 PTEN DECEMBER 2017 www.VehicleServicePros.com
After the alignment is done, a technician
can use a bi-directional scan tool to complete a
steering angle reset. This scan tool from Autel,
the MaxiSYS commercial vehicle diagnostics
scan tool, No. MS908CV, performs enhanced
system diagnostics on more than 60 commercial
light duty, medium duty and heavy duty vehicle
brands. It is built on the MaxiSYS Androidbased
platform and comes with the compact
size J2534 MaxiFlash Elite to perform pass-thru
programming function and complete an array of
tool-guided maintenance services, then diagnose
manufacturer specific systems.
ISSUE: Uneven side-to-side brake wear on the rear of
the vehicle caused by left rear brake sticking after driving
VEHICLE:
2013 VW Beetle
a vehicle will come in
with an issue that seems
common, but after you
perform all the normal
service steps it turns out the issue is far
from normal.
You may think that uneven brake
wear and a sticking brake would be taken
care of with a normal brake service and
replacement of the calipers. This VW
had been sent to us from a shop that had
repaired or replaced all the common parts
that typically cause such an issue.
In cases like this, where parts have
been replaced by another shop, diagnosis
may be more complicated because you do
not have the original worn parts to assist
you in determining what the possible
cause of the issue may be. Additionally,
you cannot be sure the parts that have
been replaced were of high quality, or
were even the correct ones. Compounding
these possibilities is a chance the work
itself was not performed correctly.
1 OBTAIN INFORMATION
As always, information is the key
to a successful repair. Obtain details such
as when the issue occurs. This could mean
the time of day, how long the vehicle has
been driven, how long it has been since
it was driven, how often or intermittent
it happens, and when the problem first
started.
Beyond repair history, having access
to specifications, repair procedures and
TSBs is necessary to complete a quick and
accurate diagnosis and repair. With the
abundance of vehicle information available
(and the great job the vehicle information
providers are doing to make it
available) it may be preferable to rely on
more than one source to get as much data
as possible.
On this vehicle we used Mitchell 1,
IdentiFix and IATN to look for TSBs,
specifications, and to check to see if
there had been other vehicles with similar
issues. There were no specific TSBs, but
we did find a couple of interesting items
we will point out later in this article.
Since this vehicle came from another
shop, a complete history was not available
to us without speaking to the vehicle
owner directly, so we would need to rely
on the information the other shop provided.
The other shop said the vehicle originally
came in for brake service and the
customer stated the rear brakes had been
replaced somewhat recently and seemed
to smell at times. They found the left rear
brake pads excessively worn, and the rotor
showed signs of overheating. Not finding
any current issues, they replaced the rear
calipers and rotors, checked the parking
brake and bled the system.
After about 5,000 miles, the customer
returned complaining the brakes still
smelled. The shop checked the brakes and
found the left rear brake excessively worn
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