BENDIX BW7257 Manual De Usuario
12
Brake Adjuster Maintenance–General
Service Intervals
Lubrication
Caution: Do not use moly-disulfide loaded grease or oil because
they may shorten brake adjuster service life. Do not use
pressure-release grease fittings.
they may shorten brake adjuster service life. Do not use
pressure-release grease fittings.
Important: In no case should the lubrication interval exceed the
published intervals in table above.
published intervals in table above.
Lube Free Spicer
®
brand self adjusting brake adjusters are lubricated
at the factory with a proprietary grease and do not require lubrication
at service intervals.
at service intervals.
Note: Spicer
®
brand self adjusting brake adjusters manufactured after
May 30, 1996 have incorporated an improved sealing and grease
filling technique. This makes it possible to extend service
intervals, thus reducing maintenance.
filling technique. This makes it possible to extend service
intervals, thus reducing maintenance.
Inspection
Bendix Spicer Foundation Brake strongly recommends that
routine visual/operational checks, including brackets and control
arms, be performed at each Preventative Maintenance Service
Interval.
routine visual/operational checks, including brackets and control
arms, be performed at each Preventative Maintenance Service
Interval.
Adjusters or anchor brackets that have visual damage, or which
fail the operational checks, MUST be replaced immediately.
fail the operational checks, MUST be replaced immediately.
Inspect brake adjuster and anchor bracket for damage. Check
that anchor bracket is tight and the control arm is in the full
release position.
that anchor bracket is tight and the control arm is in the full
release position.
Note: If self adjusting brake adjuster is equipped with indicator
arrow, make sure the indicator is within the slow when the brake
is in the release position.
arrow, make sure the indicator is within the slow when the brake
is in the release position.
Automatic adjusters should not be operated as manual adjusters
except as may be necessary to get the vehicle off the road for
service.
except as may be necessary to get the vehicle off the road for
service.
Maintaining proper brake adjustment and brake balance cannot
be accomplished by the brake adjuster alone. The condition of founda-
tion brake components have a direct bearing on the
effectiveness of brake adjustment. Inspect foundation brake
components periodically.
be accomplished by the brake adjuster alone. The condition of founda-
tion brake components have a direct bearing on the
effectiveness of brake adjustment. Inspect foundation brake
components periodically.
Maintenance
Brake Air Chambers
Check that brake air chamber mounting bolts are tight and properly
aligned to avoid interference between air chamber pushrod and air
chamber housing.
aligned to avoid interference between air chamber pushrod and air
chamber housing.
Verify that brake chamber pushrod length is equal on both brake
chambers of the same axle.
chambers of the same axle.
Camshaft Bushings
Worn “S” cam bushings will increase push rod travel. Replace
bushing if worn and at each reline.
bushing if worn and at each reline.
For detailed inspection procedure on foundation brake components
refer to Bendix Spicer Foundation Brake service manual BW7258.
refer to Bendix Spicer Foundation Brake service manual BW7258.
Wheel Bearing Adjustment
Accurate wheel bearing preload is necessary to maintain proper
alignment between the brake drum and brake shoes.
alignment between the brake drum and brake shoes.
Checking Release Torque
The following procedure verifies proper operation of the automatic
brake adjuster.
brake adjuster.
Place a torque wrench on the 7/16" adjusting hex. (See Figure 19.) Turn
the torque wrench counterclockwise. The clutch should not slip at a torque
less than 13 lb. ft. (18 N•m). A racheting sound occurs when the clutch
slips. If clutch slips at a lesser torque, replace the adjuster.
the torque wrench counterclockwise. The clutch should not slip at a torque
less than 13 lb. ft. (18 N•m). A racheting sound occurs when the clutch
slips. If clutch slips at a lesser torque, replace the adjuster.
RACHETING SOUND OCCURS
WHEN CLUTCH SLIPS
13 lb. ft.
(18 N•m)
Figure 19 Checking Release Torque
Component
Standard
Low Lube
Lube Free
Visual Inspection
During normal chassis
lubrication or 3 months
which ever occures first.
Lubrication Interval
Adjusters manufactured prior to 6/1/96 –
every 50,000 miles or every 3 months.
Adjusters manufactured
after 6/1/96 – once a year.
Once a year
None
Type of Lubricant
Standard Chassis Grease
SHC 460 Synthetic
*Lubricated at Factory
*Lube free Spicer
®
brand self adjusting brake adjusters are manufactured without a grease fitting.