Meritor MM-2075 Maintenance Manual page 27

Condition Possible Causes
Long stopping Incorrect brake friction for vocation
distance
Brake lining wear
Brake lining contamination
Brake pressure restriction
Insufficient hydraulic pressure
Brake Drag - One
Residual pressure in caliper or delay
wheel end in fluid pressure relief from the caliper
after the brake is applied
Brake Drag
Described - a
wheel end does not
rotate freely when
brake not applied.
Brake pad binding in caliper
Free rotation
is subjective
and should be
compared to a
wheel end not
experiencing
the issue being
investigated.
Brake not releasing - piston seized
Drive axle wheel
ends will have
some level of
system friction
to consider when
checking due to
drive train.
Incorrect brake pads - excessive swell
and growth
Loose or worn wheel bearing
(16579)
Printed in USA
Check for
Verify brake friction is OEM approved
Check for pad wear condition
Check brake pads for grease, oil,
contaminates
Check brake system for obstruction
Verify system pressure at caliper
Caliper crossover tube damaged
restricting fluid to outboard caliper
Jounce hose collapsed/damaged
Damage/restriction to brake fluid
supply line
Debris/contaminates in brake fluid
creating restriction in brake line
Dirt, debris and corrosion on brake
pad abutment plate
Damaged/deformed abutment plate
limiting brake pad movement
Brake pad backing corrosion/damage
Pad retainer spring deformed or
damaged
Check if piston can be seated into
piston bore. If the piston can be
moved, then there is another issue.
*Piston OD to caliper bore is tightly
controlled dimension. Over extended
pistons require attention when seating
to avoid alignment induced binding.
Verify using OEM brake pads
Check wheel end play
Copyright Meritor, Inc., 2023
9 Troubleshooting
Correction
Replace brake pads as needed with
OEM brake pads.
Replace brake pads as needed with
OEM brake pads.
Replace brake pads as needed with
OEM brake pads.
Replace as needed.
Investigate system delivery issue.
Replace crossover tube.
Replace jounce hose.
Replace damaged hose, bleed brakes
and verify issue resolved.
Bleed brake and verify brake releases
properly.
Clean abutment plate and verify brake
pads move freely in caliper.
Replace abutment plates and verify
brake pads move freely in caliper.
Replace brake pads and verify brake
pads move freely in caliper.
Replace pad retainer spring.
Seized piston
Service seized piston or replace
caliper.
Piston moves
Not a piston issue. Further
investigation required.
Replace with OEM brake pads.
Adjust or replace wheel bearing.
MM-2075 / Revised 09-23
Page 23