Snap-On EEWH311C, Operator'S Manual

Page: 24 / 84

EEWH311C 24
5.3 OPERATING THE PNEUMATIC BEAD ASSIST
The EEWH311C Air-Electric Models is equipped with
a specially designed “Pneumatic Bead Assist Device”
(referred to as the PBA). The PBA offers the combined
benefi ts of both reducing the amount of physical exertion
required by the tire technician as well as providing an
added level of safety by allowing the machine to do the
work rather then the technician. Simply put the PBA
allows the technician to apply pneumatic power when
most needed in the tire changing process.
The PBA consists of three separate devices which are
attached to a powerful pneumatic cylinder which raises
and lowers the devices as needed.
First is the Upper Bead Roller. The Bead Roller can
be used to drive stiff upper beads down into the drop
center of the rim. This function will be useful both when
lubricating a tire prior to being removed from the rim
as well as when remounting the second bead of a High
Performance or Runfl at design tire (Fig. 5.3-1).
901
Fig. 5.3-1
Move the bead roller into position overtop of the tires
sidewall. While the turntable is turning lower the roller
down into contact with the sidewall. Depress the bead
down 1-2” now you may insert the lubrication swab to
safely lubricate the upper bead.
Second is the Bead Depressor. The Bead Depressor
consists of a formed rubber head mounted on a movable
arm designed to comfortably depress the tires sidewall.
The size and mobility of the arm will allow the formed head
to depress the tire at any position around the 360 degrees
of rotation. The Bead Depressor will be useful numerous
times throughout the remount cycle. When remounting
a tire the bead depressor will ensure that the bead stays
down in the drop center of the rim until the entire bead
has been remounted onto the rim.
Once the fi rst bead has been remounted move the bead
depressor into position just behind the mount demount
head. Now depress the second bead down 1-3” . Activate
the turntable, as the second bead moves across the
mount/demount head the bead depressor will follow the
tire around and ensure that the bead does not prematurely
seat causing the mount/demount head to jam (Fig. 5.3-2).
905
Fig. 5.3-2
The third tool integrated into the PBA is the Bottom Bead
Roller. This device will be useful at several times during
the demount cycle. First the bottom roller can be used to
unseat a stubborn lower bead which may have re-seated
after the bead breaking process and before tire removal.
Secondarily the lower disk can be used to hold a wide tire
up after the fi rst bead has been removed. This will assist
in getting the second bead up onto the mount demount
head (Fig. 5.3-3).
903
Fig. 5.3-3
When working to loosen a stubborn lower bead simply
swing the bottom bead roller under the lower sidewall and
apply slow upward pressure. Be careful not to mistakenly
swing far enough in to contact the rim.
When working to safely secure the second bead for
removal, insert the tire tool all the way past fi rst and
second bead. Now swing the bottom bead roller into
position under the lower sidewall and lift. As the sidewall
comes up, so will the tire bar easily fl ipping onto the
mount/demount head.