COATS Extended Mobility (EMT) RunFlat Tires - Manual (Page 10)

A–2 Overview
These tires also require the tire service technician to be
extra cautious. In every case, there will be a low pressure
sensor of some type installed on the wheel. When standard
tire changing procedures are used on these tires the sensors
will be damaged. If not properly serviced, these sensors are
easily damaged and expensive to replace. Knowing the
proper method of changing a tire on a wheel equipped with
a sensor, and how the sensors themselves are installed, will
save the technician valuable time and resources and avoid
headaches and frustration.
Before you begin, take a good look at the tire and wheel.
There are things that the technician may take for granted
when changing standard tires that can have a dramatic
effect when changing these new tires. For example: on steel
wheels, watch for curb damage on the wheel rim flange that
is rough or sharp. The beads on these tires are pulled tightly
across this flange, and rough, sharp edges can seriously
damage the beads.
The tire service technician will also need to spend increased
time cleaning and polishing the wheel. These tires are very
inflexible, and will pull and slide against the wheel surfaces
much more than a standard tire. Keeping the wheel clean
and polished smooth will reduce friction and allow the tire to
move easier during the mounting and bead sealing process.
These tires made their debut on specialty vehicles like the
Corvette. Because of their “high performance” nature, these
tires are, in many cases, position–and directional–specific.
This means that they may be designed to roll in one direction
only, or to be placed in a front or rear position only. Or, in
some cases, they are totally position-specific, designed for
placement as right front, left rear, etc. This information is
included on the sidewall of the tire. The technician needs to
be aware of these specifics to ensure that tires are properly
mounted and positioned.
Many alloy wheels today are location-specific as well.
These wheels may have additional offsets to compensate for
brakes or other suspension requirements. This information is
usually included on the inside of the wheel. The technician
must also be aware of “reverse mount” wheels–where the
drop center (or short side of the wheel) is toward the inner
plane of the wheel instead of outer. Tires are always mount-
ed from the short side, so reverse mount wheels will be
mounted to the tire changer “upside down” from
normal–with the inside of the wheel facing upwards.
Safe tire inflation is of the utmost importance.
These new tires are much tougher to bead seat and inflate.
Because they are so stiff, a bead seating pressure that
exceeds 40 PSI may be required. For this reason, a safety
cage must be used for bead seating and inflation of
EMT/RunFlat Tires. Read and follow ALL the safety instruc-
tions provided in this publication and your tire changer manual.
This completes Section A.