!

CAUTION

POTENTIAL ASBESTOS DUST HAZARD!
Some older brake linings may contain asbestos dust, which has been
linked to serious or fatal illnesses. Certain precautions need to be
taken when servicing brakes:
1. Avoid creating or breathing dust.
2. Avoid machining, filing or grinding the brake linings.
3. Do not use compressed air or dry brushing for cleaning (dust can
be removed with a damp brush).

After replacement of brake shoes and linings, the brakes must be re-burnished
to seat in the new components. This should be done by applying the brakes 20
to 30 times from an initial speed of 40 m.p.h., slowing the vehicle to 20 m.p.h.
Allow ample time for brakes to cool between applications. This procedure allows
the brake shoes to seat in to the drum surface.

-32-

Check all hardware. Check shoe return spring, hold down springs, and adjuster
springs for stretch or wear. Replace as required. Service kits are available.

Instructions for Brake Caliper Kit
3.5K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.
Remove the old brake caliper
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

!

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.

2. Remove the wheel from the hub, leaving the brake exposed.
3. Disable the brake actuation system. Check that the hydraulic system has
zero pressure and that the hub and rotor rotate freely.
4. Remove the hose from the caliper, then remove the two caliper mounting
bolts. Do not allow the caliper to hang from the hose.

-33-

Braking Systems - Hydraulic

Hardware

Installing the new brake caliper
1. First, inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.
2. Install the new caliper assembly. Make sure that the bleed screw points
up.
3. Remount the caliper assembly onto the caliper attaching bracket.
Ensure that there is thread locking compound on the threads of the new
mounting bolts. Torque mounting bolts to 40-50 Ft. Lbs.
Note: Use two lug nuts to secure rotor against the hub face when
reassembling the caliper. After the caliper is assembled remove the lug
nuts.
4. Reconnect the hose to the elbow adapter on the back of the caliper and
torque to 10-12 Ft. Lbs.
5. Reconnect the brake actuation system. Refer to your actuation systems
Operation Maintenance Service Manual for proper operation.
6. Bleed and flush brake system per your actuation systems Operation
Maintenance Service Manual.

Braking Systems - Hydraulic

7. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.

Instructions for Brake Rotor Kit
3.5K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.
Remove the old brake rotor
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

-34-

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.
2. Remove the wheel from the hub, leaving the brake exposed.
3. Disable the brake actuation system. Check that the hydraulic system has
zero pressure and that the hub and rotor rotates freely.
4. Remove the two caliper mounting bolts. Do not allow the caliper
assembly to hang from the hose. Do not disconnect the hose or allow air
into the hydraulic system.
5. With the caliper assembly out of the way remove the brake rotor. Save
the brake mounting hardware for reinstalling the brake calipers.
Installing the new brake rotor
1. First inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.
2. Install the new brake rotor by fitting it onto the hub flush with the hub
face.
3. Remount the caliper assembly onto the caliper attaching bracket. Place
thread locking compound on threads of mounting bolts. Torque mounting
bolts to 40-50 Ft. Lbs.
Note: Use two lug nuts to secure rotor against the hub face when
reassembling the calipers. After the calipers are assembled remove the
lug nuts.
4. Reconnect the brake actuation system. Refer to your Operation
Maintenance Service Manual for proper operation.
5. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.

-35-

Braking Systems - Hydraulic

!

Instructions for Brake Rotor Kit
6K or 8K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.
Remove the old brake rotor
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

!

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.
2. Remove the wheel from the hub, leaving the brake exposed.

Braking Systems - Hydraulic

3. Disable the brake actuation system. Check that the hydraulic system has
zero pressure and that the hub and rotor rotates freely.
4. For brakes produced after April 2008, locate the crossover brake line
threaded into the bottom side of both calipers. The crossover brake line
is attached to the inboard side of the anchor yoke using a metal tube
clamp. Remove the
1/4-20 bolt that connects the tube clamp to the yoke.
5. Remove the four caliper mounting bolts. Do not allow the caliper
assembly to hang from the hose. Do not disconnect the hose or allow air
into the hydraulic system.
6. With the caliper assembly out of the way remove the brake rotor. Save
the brake mounting hardware for reinstalling the brake calipers.

-36-

2. Install the new brake rotor by fitting it onto the hub flush with the hub
face.
Note: Use two lug nuts to secure rotor against the hub face when
reassembling the calipers. After the calipers are assembled remove the
lug nuts.
3. Remount the caliper assembly onto the caliper attaching bracket. It
may be necessary to push the piston into the calipers to obtain enough
clearance. Torque mounting bolts to 25-35 Ft. Lbs.
4. For brakes produced after April 2008, locate the tube clamp attached
to the crossover brake line and attach to the caliper mounting bracket.
Using the 1/4-20 bolt, torque to 85-100 In. Lbs.
5. Spin the rotor to ensure that there is enough clearance between the rotor
and the crossover brake line.
6. Reconnect the brake actuation system. Refer to your Operation
Maintenance Service Manual for proper operation.
7. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.
8. Spin the wheel to ensure that there is enough clearance between the
wheel and crossover brake line or caliper.

Instructions for Brake Hub/Rotor Kit
7K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.

-37-

Braking Systems - Hydraulic

Installing the new brake rotor
1. First inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.

Remove the old brake rotor
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

!

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.
2. Remove the wheel from the hub, leaving the brake exposed.
3. Disable the brake actuation system. Check that the hydraulic system has
zero pressure and that the hub/rotor rotates freely.

Braking Systems - Hydraulic

4. For brakes produced after April 2008, locate the crossover brake line
threaded into the bottom side of both calipers. The crossover brake line
is attached to the inboard side of the anchor yoke using a metal tube
clamp. Remove the
1/4-20 bolt that connects the tube clamp to the yoke.
5. Remove the four caliper mounting bolts. Do not allow the caliper
assembly to hang from the hose. Do not disconnect the hose or allow air
into the hydraulic system.
6. With the caliper assembly out of the way, remove the brake rotor by
removing the grease or oil cap, spindle nut and outer bearing, then pull
hub/rotor off the spindle.
Installing the new brake hub/rotor
1. First inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.
2. Install the new brake hub/rotor assembly and outer bearing onto axle
spindle.
3. Install washer and spindle nut onto spindle to secure hub. Install nut
per the bearing adjustment procedure in your Operation Maintenance
Service Manual.
-38-

5. Remount the caliper assembly onto the caliper attaching bracket. It
may be necessary to push the piston into the calipers to obtain enough
clearance. Torque mounting bolts to 25-35 Ft. Lbs.
6. For brakes produced after April 2008, locate the tube clamp attached
to the crossover brake line and attach to the caliper mounting bracket.
Using the1/4-20 bolt, torque to 85-100 In. Lbs.
7. Spin the hub/rotor to ensure that there is enough clearance between the
rotor and the crossover brake line.
8. Reconnect the brake actuation system. Refer to your Operation
Maintenance Service Manual for proper operation.
9. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.
10. Spin the wheel to ensure that there is enough clearance between the
wheel and crossover brake line or caliper.

Instructions for Brake Pad Kit
6K, 7K or 8K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.
Remove the old brake pads
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

-39-

Braking Systems - Hydraulic

4. Ensure spindle nut retainer is in place. Install new grease or oil cap with
rubber plug, and torque as shown on cap.

!

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.
2. Remove the wheel from the hub, leaving the brake exposed.
3. Disconnect the brake actuation system. Check that the hydraulic system
has zero pressure and that the hub and rotor rotates freely.
4. Remove the brake pad retaining pin.
5. Remove the old pads from the caliper assembly. Save the brake pad
retaining hardware for reinstalling the new pads onto the caliper.

Braking Systems - Hydraulic

!

CAUTION

POTENTIAL ASBESTOS DUST HAZARD!
Some older brake linings may contain asbestos dust, which has been
linked to serious or fatal illnesses. Certain precautions need to be
taken when servicing brakes:
1. Avoid creating or breathing dust.
2. Avoid machining, filing or grinding the brake linings.
3. Do not use compressed air or dry brushing for cleaning (dust can
be removed with a damp brush).
Installing the new brake pads
1. First inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.
2. Press the caliper pistons into the calipers until enough clearance is
available to fit the new pads between the pistons and the rotor.

-40-

3. Install the new brake pads by sliding them in one at a time between the
caliper pistons and the rotor. The pads are the same for the inner and
outer side of the rotor. Make sure the brake lining side of the pad faces
the rotor, and the steel backing faces the caliper pistons.
4. Align the brake pad mounting holes with the holes in the caliper. Insert
one of two brake pad retaining bolts into each caliper half as shown
below in Figure 1. Place the anti‑rattle spring against the brake pads
and press the center toward the rotor while you slide the outboard pad
retaining bolt toward the inner lining. Continue sliding the pad retainer
bolts until it engages both pads and pushes the second bolt out of the
inboard caliper half. Install and torque lock nut until threads stop.

Figure 1
5. Reconnect the brake actuation system. Refer to your Operation
Maintenance Service Manual for proper operation.
6. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.

-41-

Braking Systems - Hydraulic

Note: Use two lug nuts to secure rotor against the hub face when
reassembling the new pads. After the pads are assembled remove the
lug nuts.

Instructions for Brake Caliper Kit
6K, 7K or 8K Hydraulic Disc Brakes
Notice to Buyer
It is recommended that all brakes be replaced at the same time to ensure
balanced braking performance.
Remove the old brake calipers
1. Jack up trailer and secure on adequate capacity jack stands. Follow
trailer manufacturers recommendations for lifting and supporting the
unit.

!

CAUTION

Do not lift or support the trailer on any part of the axle or suspension
system. Never go under any trailer unless it is properly supported on
jack stands which have been rated for the load. Improperly supported
vehicles can fall unexpectedly and cause serious injury or death.
2. Remove the wheel from the hub, leaving the brake exposed.

Braking Systems - Hydraulic

3. Disable the brake actuation system. Check that the hydraulic system has
zero pressure and that the hub and rotor rotates freely.
4. For brakes produced after April 2008, the crossover brake line also
attaches to the inboard side of the caliper mounting bracket using the
metal tube clamp. Slide the clamp over the crossover brake line and
bend it to the closed position. Apply anti-seize or similar thread lubricant
to the 1/4-20, 1/2" bolt. Attach the tube clamp to the threaded hole in
the caliper mounting bracket using the 1/4-20, 1/2" length bolt. Torque
to 85-100 In. Lbs.
5. Remove the hose from the caliper, then remove the four caliper mounting
bolts. Do not allow the caliper to hang from the hose.
Installing the new brake caliper
1. First inspect the brake assembly for grooves, flaking, cracks, heat
checking, thickness variation, insufficient rotor thickness, and look to
see that the mounting hardware is straight. Replace any component as
needed (or desired) per manufacturer recommendations.

-42-

Note: Use two lug nuts to secure rotor against the hub face when
reassembling the calipers. After the brake is assembled, remove the lug
nuts.
3. One caliper will be used on the inboard side, with the hydraulic line
fitting adapter installed on the top side of the piston boss. The other
caliper will be used on the outboard side with the bleed screw installed
at the top of the piston boss. Install both of these calipers onto the
attaching bracket. Make sure that the bleed screw points up and is
located on the outboard caliper. Torque bolts to 25-35 Ft. Lbs.
4. Connect the new crossover brake line on the bottom sides of the piston
boss on both calipers.
Note: Make sure the crossover line fits snug around the calipers and
rotor without touching the rotor. Spin the rotor to ensure there is proper
clearance. Torque the crossover line to 12-15 Ft. Lbs. Torque the bleed
screw and the hydraulic line fitting adapter to 60-76 Inch Lbs.
5. For brakes produced after April 2008, locate the crossover brake line
threaded into the bottom side of both calipers. The crossover brake line
is attached to the inboard side of the anchor yoke using a metal tube
clamp. Remove the
1/4-20 bolt that connects the tube clamp to the yoke.
6. Reassemble the brake pads into the disc brake. Make sure to locate the
brake lining side of the pads toward the rotor surface, and the steel side
of the pads toward the calipers. Align the brake pad mounting holes with
the holes in the caliper. Insert one of two brake pad retaining bolts into
each caliper half as shown previously in Figure 1. Place the anti‑rattle
spring against the brake pads and press the center toward the rotor
while you slide the outboard pad retaining bolt toward the inner lining.
Continue sliding the pad retainer bolt until it engages both pads and
pushes the second bolt out of the inboard caliper half. Install and torque
locknut until threads stop.

-43-

Braking Systems - Hydraulic

2. Assemble the new caliper assembly.

7. Reconnect the brake actuation system. Refer to your Operation
Maintenance Service Manual for proper operation.
8. Bleed and flush brake system per your actuation systems Operation
Maintenance Service Manual.
9. Remount the wheel. Refer to your Operation Maintenance Service
Manual for proper wheel nut torque procedures.

Braking Systems - Hydraulic

10. Spin wheel to ensure proper clearance between the wheel and crossover
brake line or caliper.

-44-

Proper brake function is critical to the safe operation of any vehicle. A properly
installed vacuum/hydraulic, electric/hydraulic, or air/hydraulic system should
not require any special attention with the exception of routine maintenance as
defined by the manufacturer. If problems occur, the entire tow vehicle/trailer
braking system should be analyzed by a qualified mechanic. Typical problems in
a hydraulic braking system are:
•
•
•
•
•
•

Air or vacuum leaks
Hydraulic system leaks
Air in brake lines
Water or other impurity in brake fluid
Rusted or corroded master or wheel cylinders
Actuation system malfunction

Please consult the following troubleshooting charts to determine the causes and
solutions for common problems found in trailer braking systems.

CAUTION
The maximum operating pressure for Dexter brakes:
• 7" diameter drum brakes
maximum operating pressure is 750 psi
• 10" diameter and larger drum brakes
maximum operating pressure is 1,000 psi
• Hydraulic disc brakes (all sizes)
maximum operating pressure is 1,600 psi

-45-

Braking Systems - Hydraulic

Introduction to Troubleshooting

Troubleshooting
SYMPTOM

No Brakes

CAUSES

REMEDIES

Broken or Kinked
Brake Line

Repair or Replace

Severe
Underadjustment

Adjust Brakes

Malfunctioning
Actuation System

Troubleshoot System

Brake Adjustment
Not Correct

Manual-Adjust Brakes
Automatic-Make Several
Reverse Stops

Excessively Worn
Brake Linings

Replace Shoe
and Lining

Incorrect Lining

Install Correct
Shoe and Lining

Grease or Fluid
Soaked Lining

Repair Grease Seal or
Wheel Cylinder. Install
New Shoe and Lining.

Frozen Master Cylinder
or Wheel Cylinder Pistons

Recondition or Replace
All Cylinders, Brake Fluid

Glazed Lining

Reburnish or Replace

Excessive Drum Wear

Replace

Trapped Air in Lines

Bleed System