mm4.bk.fm - mm4 - spartan emergency response · with 1.30" clevis pin spacing ″ ″ ″...

4 Prepare Parts for Assembly

23Meritor Maintenance Manual 4 (Revised 08-16)

4. Inspect the boot assembly. If it is cracked, cut or torn, remove

the pull pawl and inspect the areas around the actuator. If you

find dirt, solid lubricant or corrosion, replace the slack adjuster.

Otherwise, only replace the boot assembly.

5. Use a grease gun to apply Meritor-approved lubricant to the

slack adjuster grease fitting, until grease flows from around the

camshaft splines and pawl assembly. Refer to Section 7. If

necessary, install a camshaft into the slack adjuster gear to

minimize grease flow through the gear holes.

CamshaftCheck the camshaft for cracks, wear and corrosion. Check the cam

head, bearing journals and splines. Replace worn or damaged

camshafts.

Install new camshaft bushings and seals whenever you install a new

camshaft.

1. Tighten all spider bolts to the correct torque. Figure4.4. @

Figure 4.4

2. Use a seal driver to install new camshaft seals and new

bushings into the cast spider and camshaft bracket.

Figure4.5.

If the brake has a stamped spider: Install both bushings

into the bracket. Install the seals with the seal lips toward

the slack adjuster to ensure grease purges at the slack end.

Figure4.6.

Figure 4.5

Figure 4.6

3. If the camshaft bracket has been removed, install the chamber

bracket seal and bracket onto the spider. Tighten the

capscrews to the correct torque. Figure4.4. @

Camshaft Bushing Journals

1. Inspect the two bushing journals on each camshaft for wear.

2. Remove any debris from the camshaft bushing journals to

ensure an accurate measurement.

3. Use a 1-2-inch machinist’s caliper to measure the bushing

journals on each camshaft. Take the measurement in multiple

positions on the bushing journals as the camshaft and bushing

may wear unevenly. Camshaft journal diameter must be no less

than 1.490-inches (37.846 mm). Figure4.7. @

If any measurement taken on the camshaft bushing

journal surface is less than 1.490-inches (37.846 mm):

Replace the camshaft.

Figure4.4

Bolt Size Torque

7/16"-20 60-75 lb-ft 81-102 N m1/2"-20 85-115 lb-ft 115-156 N m9/16"-18 130-165 lb-ft 176-224 N m5/8"-18 180-230 lb-ft 244-312 N m7/8"-9 440-580 lb-ft 598-789 N m

4000345a

Figure4.5

Figure4.6

4000346a

SPIDER

CAMSHAFTBRACKET

SEALLIP

SEALLIP

4000347a

″

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Darkbrown

Tan

White

Cool grey

TP-4786

TP-4787

TP-4781

TP-10130

Truck or tractor drum brakewith 1.38" clevis pin spacing

Trailer drum brake

Coach drum brake with 7-inch or bolt-on slack adjuster

Truck or tractor drum brake with 1.30" clevis pin spacing

″

″

″

Meritor Automatic Slack Adjuster Installation Template for Trucks/Tractors with Drum Brakes with 1.38" Hole Clevis

5" 5.5" 6" 6.5"2297-B-4786 Rev. ”J“SUPERSEDES TP-ASA-1TP-4786

1.38" CLEVISPIN SPACING

BSAP 2.75"FOR BRACKET OFFSETS 3.75" & 3.81"

PLACE ON CAMSHAFT CENTER

ADJUST CLEVIS UNTIL

SMALL CLEVIS PIN

IS WITHIN SLOT

IF T

HIS

EN

D O

F TE

MPLA

TE F

ITS

BET

WEE

N C

LAM

P B

AN

DS O

F SPRIN

G

CHA

MB

ER, I

T IS

A L

ON

G S

TROKE

PLACE OVER LARGE CLEVIS PIN

SLACK ADJUSTER ARM LENGTH

Meritor Automatic Slack Adjuster Installation Template for Trucks/Tractors with Drum Brakes with 1.30" Hole Clevis

5" 5.5" 6" 6.5"

2297-Y-8813 Rev. ”B“TP-10130




ADJUST CLEVIS UNTIL

SMALL CLEVIS PIN

IS WITHIN SLOT

IF T

HIS

EN

D O

F TE

MPLA

TE

FITS

BETW

EEN

CLA

MP B

AN

DS O

F SPRIN

G

CHA

MB

ER, I

T IS

A L

ON

G S

TROKE



5" 5.5" 6" 6.5"2297-C-4787 Rev. ”G“SUPERSEDES TP-ASA-2TP-4787


Meritor Automatic Slack Adjuster Installation Template for Trailers with Drum Brakes

ADJUST CLEVIS UNTIL

SMALL CLEVIS PIN

IS WITHIN SLOT

IF T

HIS

EN

D O

F TE

MPLA

TE

FITS

BET

WEE

N C

LAM

P B

AN

DS O

F SPRIN

G

CH

AM

BER, I

T IS

A L

ON

G S

TROKE




″

″ ″

″ ″ ″

″


ADJUST CLEVIS UNTILSMALL CLEVIS PINIS WITHIN SLOT



Automatic Slack AdjusterTemplate for Coaches with Drum Brakes

5.5" 7"

2297

-W-4

781

Rev

. ”K“

TP-4

781

Meritor Automatic Slack Adjuster Installation Template for Trucks/Tractorswith Drum Brakes with 1.30" Hole Clevis

5" 5.5" 6" 6.5"

2297-Y-8813 Rev. ”B“TP-10130




ADJUST CLEVIS UNTIL

SMALL CLEVIS PIN

IS WITHIN SLOT

IF T

HIS

EN

D O

F TE

MPLA

TE F

ITS

BET

WEE

N C

LAM

P B

AN

DS O

F SPRIN

G

CH

AM

BER

, IT

IS A

LON

G S

TROKE



″

± ″

″

″

″

″

″

″

″ ″

″

± ″

″

″

″

″

″

″ ″

″ ″

″

± ″

″

″

″

″

″

5 Assembly and Installation


7. Install the anchor pin washers, felts, seals, retainers and snap

rings, if required. Install lock pins or lock screws, if required.

Tighten the screws to 10-15 lb-ft (13.6-20.3 Nm). @

8. Install a new shoe return spring onto the brake shoe.

Figure5.30. Place the upper brake shoe into position over the

spider. Repeat Steps 5-6.

Figure 5.30

T Series Cam Brake

1. Lubricate the shoe rollers and anchor pins as shown in

Figure5.28. Use only Meritor-approved grease. Refer to

Section 7 for approved grease specifications.

2. Install the anchor pins, washers and nuts onto the backing

plate if you removed these parts previously. Tighten the anchor

pin nuts to 185-350 lb-ft (251-475 Nm). @

3. Install the anti-rattle rod. Install the brake shoe onto the anchor

pins and anti-rattle rod.

4. Install the anchor pin snap rings, anti-rattle spring and

anti-rattle retainer spring onto the anti-rattle rod.

5. Pull the brake shoe away from the camshaft to enable you to

install the brake shoe roller. Install a new brake shoe return

spring onto the brake shoe.

Brake Shoes Equipped with a Lining Wear Sensor

Before disassembly, note the routing of the sensor wiring. The

wiring harness passes through a dust shield grommet that must be

removed in order to pull the harness connector through the dust

shield. The replacement assembly contains a new dust shield

grommet. Ensure that you route and secure the sensor wiring in the

same manner. Reinstall the connector end of the sensor wiring to

the main harness.

The brake shoe assembly includes a lining wear sensor. The sensor

is located in the primary shoe lining block closest to the camshaft on

the inboard side. The first shoe past the camshaft in the direction of

wheel rotation is the primary shoe.

The primary shoe can either be on the top or the bottom position,

depending on the location of the cam. If the cam is behind the axle,

the top shoe is the primary shoe. If the cam is in front of the axle,

the bottom shoe is the primary shoe. Figure5.31.

The preferred sensor position is the primary shoe, cam end block,

inboard center rivet. Figure5.32.

Figure 5.31

Figure5.30

4000368a

Figure5.31

WHEEL ROTATION WHEEL ROTATION

WHEEL ROTATIONWHEEL ROTATION

CAM BEHIND AXLE

CAM IN FRONT OF AXLECAM BEHIND AXLE

CAM IN FRONT OF AXLE

PRIM

ARY SHOE

SECONDARY SHOE

CAM

SECONDARY SHOE

PRIMARY SHOE

CAMANCHOR ANCHOR

SECONDARY SHOE

PRIMARY SHOE

PRIM

ARY SHOE

SECONDARY SHOE

4006499c

ANCHOR ANCHORCAM

LEFT FORWARD WHEEL ROTATION

RIGHT FORWARD WHEEL ROTATION

CAM

CAM

° °

° °

° °

° °

− ° − °

− ° − °

− ° − °

− ° − °

− ° − °

− ° − °

8 Diagnostics

56 Meritor Maintenance Manual 4 (Revised 08-16)

Shimmy or vibra-

tion occurs when

brakes are applied.

Radial wheel end runout is excessive (as measured on the fric-

tion surface of an assembled drum).

Verify correct hub mounting and wheel bearing end

play. If both are correct/within specification, refer to

“Check Runout on an Assembled Brake Drum” in

Section 6 of Maintenance Manual MM-99100,

Wheel Equipment, Disc Wheel Hubs, Brake Drum

Failure Analysis.

The hub-piloted brake drum is mounted incorrectly. Remove the drum and inspect the hub pilots for

damage. Clean the drum mounting surfaces on hub

and drum. Re-mount the brake drum onto the hub,

making sure the drum pilot bore is correctly seated

on the hub pilots.

Wheel bearing end play is excessive. Adjust or repair the wheel bearings to the correct

manufacturer’s specification.

Drum is out of balance or missing weights. Repair or replace the drum per the manufacturer’s

guidelines.

Discrepancies exist in brake adjustment. Follow the diagnostic procedure for "The adjusted

stroke is too short" or "The adjusted stroke is too

long" as it applies.

Brake wear is inconsistent. Perform the Brake Burnish procedure found in the

Assembly Section of this manual.

Brake components (i.e. springs, rollers retainers) are broken or

missing

Repair or replace components as necessary.

Different length slack adjusters are used on the same axle. Install the same length slack adjusters from the

same manufacturer on the same axle.

Different brake chamber sizes are used on the same axle. Install the same size and type brake chambers on

the same axle.

Brake attaching hardware is broken, loose or missing. Repair or replace components as necessary.

Tire runout is excessive. Verify the tire radial runout is below the manufac-

turer’s maximum recommended measurement.

Replace as necessary.

Wheel lateral or radial runout is excessive. Verify the wheel lateral and radial runout are within

manufacturer’s specifications. Replace as neces-

sary.

Vehicle is out of alignment. Verify the vehicle total axle alignment (both steering

and drive axles) is within manufacturer’s

specifications. Repair as necessary.

Steering or suspension hardware or components are loose. Follow the OEM guidelines for inspection,

maintenance and repair of the steering and

suspension systems.

Symptoms Possible Causes Corrective Actions

8 Diagnostics


Brake squeal/

chatter/noise

occurs upon brake

application.

Brake components (i.e. springs, rollers retainers) are broken or

missing.

Inspect, repair and/or replace components as

necessary.

Brake attaching hardware is broken, loose or missing. Inspect, repair and/or replace components as

necessary.

Brake wear is inconsistent. Perform the Brake Burnish procedure found in the


Linings are glazed (20% or less of lining friction surface). Perform the Brake Burnish procedure found in the


Linings are glazed (greater than 20% of lining friction surface). Determine the cause of overheating in the brake

assembly and repair accordingly.

Lining selection is incorrect. Replace with original equipment lining brand and

type.

The drum brake surface is aligned with shoe high spots on the

brake lining.

Make sure the service parts are correct. Perform

the Brake Burnish procedure found in the Assembly

Section of this manual.

Symptoms Possible Causes Corrective Actions

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″

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mm4.bk.fm - mm4 - spartan emergency response · with 1.30" clevis pin spacing ″ ″ ″...

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