Section 7. Component Procedures Model 8210/8250 Maintenance Manual
DC Motors, General Electrical Components
7-84 Publication: 1146945/001, Revised: 25 Sep 2018
Motor Brush Spring Tension
Brush Spring Tension Inspection
1. If equipped with the optional keypad,
press the red OFF ( O ) key. Place the Main
ON/OFF Switch in the OFF position.
Disconnect the battery connector from the
truck.
2. Remove the lift motor cover.
3. Slide the brush up slightly in its holder.
4. Insert a paper strip between the brush
face and the commutator. See
Figure 7-100.
Figure 7-100. Motor Brush Spring Tension Inspection
5. Place a small leather loop around the coil
spring for the brush. If the brush spring
has a loop at the brush, hook the spring
scale directly to the spring.
6. Attach a 5 lb. (2.27 kg) spring scale to the
leather loop.
7. While gently pulling the scale outward,
slowly pull the paper strip in the direction
that the commutator normally rotates.
8. When the paper strip starts to move freely,
the spring scale reads the spring brush
tension.
9. Refer to the table below for correct spring
tension.
10. Repeat steps 3 through 9 for the
remaining brushes.
Paper
Coil
Spring
Leather
Loop
Motor
Minimum
Brush Length
Spring
Tension
Lift Motor 0.35 in.
(9 mm)
32 to 40 oz.
(908.8 to
1136 grams)
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