JLG DVSP Series Service Manual - Manual (Page 42)

SECTION 3 - BASE COMPONENTS
3-12 – JLG Lift – 3121136
Brake Operation (See Figure 3-7.)
When the magnetic coil is not energized (brake on), the
armature plate is pushed away from the magnetic coil sur-
face by heavy springs internally mounted in the magnetic
coil housing. This pressure forces the armature plate against
the friction brake disk holding it tight between the armature
plate and the mounting plate. The friction brake pad is
mated to the drive motor armature shaft. The brake is not
released until the magnetic coil is energized pulling the
armature plate away from the friction brake disk.
A correctly adjusted brake will ideally have a measurement
of approximately .006" (but will operate normally at .004" to
.010") between the armature plate and magnetic coil hous-
ing surface when the brakes are ENGAGED (brakes on).
Never allow any type of lubricant (oil, grease, hydraulic fluid,
etc.) to come in contact with the brake friction disk or it’s
contacting surfaces. Also if the brake becomes clogged with
debris or dirt the brake may not release properly.
Brake Assembly Removal
1. Lift the machine to gain access to the underside
(See Section 2-5.).
2. Remove the drive motor cover (See Section 3.2).
3. Disconnect the drive motor power connector from
it’s wiring harness connector.
4. Loosen the boot clamp, and slide the protective rub-
ber boot off the end of the drive motor housing
exposing the brake assembly.
5. Remove the four (4) hex cap screws securing the
brake assembly to the end of the drive motor hous-
ing and remove the brake assembly from the end of
the drive motor.
Checking/Adjusting Armature Plate Gap
Setting
1. First inspect that all parts of the brake assembly are
tight and secure. Tighten as necessary.
2. Inspect the brake for any debris which may be
lodged in the air gap between the armature plate
and magnetic coil when the brakes are ENGAGED
(brakes on); on either side of the friction disk when
the brake is RELEASED (brakes off). Clean and
remove debris as necessary.
3. With the brakes ENGAGED measure the air gap
between the armature plate and the magnetic coil
housing. The correct setting should be .006", how-
ever the brakes will operate properly if the measure-
ment is a minimum of .004" and a maximum of .010".
(See "Gap Setting" Illustration this Section)
4. If the air gap falls outside the maximum allowable
setting of .010" the friction disk has worn. To correct
this replace the disk with a new one.
5. If the air gap is below the minimum allowable setting
of .004", recheck the areas between the magnetic
coil housing, armature plate, friction disk and
mounting plate for debris. Clean as necessary.
Boot and Brake Removal
1. Protective Rubber Boot 2. Boot Clamp 3. Brake Assembly
3
2
1
1. Magnetic Coil Housing 5. Plate Springs
2. Armature Plate 6. Shim Washers
3. Friction Brake Disk 7. Spacer
4. Mounting Plate 8. Mounting Plate Screws
Figure 3-7. Brake Assembly Components
3
2
7
8
5
6
4