Service and Installation Instructions - TTT · Service Bulletin Air Brake Chambers SPRING BRAKES ñ...

TToollll FFrreeee:: ((880000)) 663311--11114444 FFaaxx:: ((331133))883322--00222255 ee--mmaaiill:: ppaarrttss@@ttttttoonnlliinnee..ccoomm

Service Bulletin Air Brake Chambers

SPRING BRAKES ñ PS MODEL

Service and Installation Instructions

When replacing or servicing any spring brake chamber, make sure to block the wheels. To prevent vehicle rollaway. DO NOT service a spring brake if it has structural damage or any kind. Replace the complete unit. Dismount a damaged spring brake by first cutting the service pushrod with an acetylene torch to relieve any force it might have. DO NOT strike any part of a spring brake chamber for any reason. This may cause structural damage Be careful not to drop a spring brake chamber at any time. A TTT PS Model spring brake chamber cannot have the emergency diaphragm replaced. Replace the whole piggyback.

WARNING!: Spring brakes contain a loaded compression spring. Property damage, injury, or death may occur if

instructions are not followed completely.



SECTION 1 Mechanical Release (Caging The Brake)

STEP 1 (Fig. 1) 1. Remove dust cap from release tool keyhole in

center of spring housing. 2. Remove release tool assembly from side pocket of

adapter base. 3. Insert release tool through keyhole in chamber into the pressure plate.

STEP 2 (Fig. 2)

1. Turn release tool º turn clockwise. 2. Pull on the release tool to seat it in the pressure

plate properly. 3. Put on release washer and nut. Tighten nut until it is finger tight.

The following steps only apply if the chamber is not pressurized.

1. To cage main spring, tighten release nut with hand wrench and make sure that the service pushrod is retracting.

2. Do not over torque release tool assembly: 35 lb. Ft. max.

Threaded portion of release tool will extend approximately 2.90 inches out of nut when fully released.

WARNING: Do not mechanically release (cage) the spring if there is any structural damage to the brake actuator. Caging the spring in such a chamber may cause serious injury or death. WARNING: Always work from the side of spring brake chamber. Never work from the front or back.

Warning: impact wrench may over torque the release tool causing pressure plate damage.

Fig 1

Fig 2



SECTION 2 Service Diaphragm Replacement

SEE FIG. 1, 2, & 3

a. Mechanically release the spring brake actuator by following steps 1 through 3 under section 1.

b. Clamp a pair of vise grips around the service push rod right next to (touching) the non-pressure housing. This cages the service return spring.

c. Remove service clamp assembly while being careful to support piggyback from falling. Remove old diaphragm.

d. Inspect all visible service brake parts. Replace damaged or worn parts.

e. Wipe off any dirt or grease in the service side of the piggyback.

f. Place the new diaphragm in between the piggyback and non pressure housing making sure they are all centered.

g. Reassemble the clamp assembly making sure all parts are seated properly and they remained centered.

h. Alternate tightening the clamp nuts to 24 lb. Ft. and remove the vice grips. i. Pressurize the service chamber by putting air into service port to a

Max. 120 psi air pressure then test for leaks around the clamps (no leaks allowed) j. Un cage release tool and put back into its pocket k. Replace dust cap back in keyhole.

WARNING: Mechanically release spring by completing steps 1 thru 3 under section 1 - MECHANICAL RELEASE.

WARNING: Check for proper service and emergencyoperation after servicing any part of actuator. Check the brake adjustment if the unit is installed on the vehicle.(Follow vehicle manufacturer instructions to adjust the

Fig 3


Service Bulletin Air Brake Chambers\

SECTION 3 Changing Position of Mounting Bolts,

Clamps, and Air Ports

SEE (Fig. 4)

a. Mechanically release the spring brake actuator by following steps 1 thru 3 under section 1.

b. Release all air pressure out of the unit. c. Clamp a pair of vice grips around the service

pushrod touching the non-pressure housing. This cages the service return spring.

d. Loosen the clamp nuts and rotate the clamp assembly and port holes to desired position. Make sure to support the piggyback from falling.

e. Inspect all visible parts and make sure there is no damage. Replace damaged parts.

f. Tighten the clamp nuts making sure all parts are seated properly and they remained centered.

g. Torque the clamp nuts to 25 lb. Ft. and remove the vice grips.

h. Pressurize the service half by putting air into the service port. Max. 120 psi air pressure then test for leaks around the clamps (no leaks allowed)

i. Un cage release tool and put back into the pocket. j. Replace dust cap back in keyhole.

WARNING: Mechanically release (cage) spring brake actuator before servicing any part of this unit.

WARNING: Check for proper service and emergency operation after servicing any part of chamber. Check the brake adjustment if the unit is installed on the vehicle. (Follow vehicle manufacturer instructions to adjust the brakes).

Fig 4



SECTION 4 Installation Instructions for Piggyback Model

a. Mechanically release the old spring brake actuator by following original manufacturers instructions.

b. Carefully remove old piggyback chamber. c. Inspect all service brake parts and replace any that are damaged.

d. Place a new diaphragm in between the new piggyback chamber by following instructions in section 1.

e. Reassemble the clamp assembly making sure all parts are seated properly and they remain centered.

f. Torque the clap nuts to 25 ft. lbs. And remove the vice grips.

g. Reconnect the emergency air line to the emergency porthole then reconnect the service air line to the service porthole.

h. Pressurize the service half by putting air into the service port. Max 120 psi air pressure then test for leaks around the clamps. (no leaks allowed)

i. Uncage the main spring and put the release tool back into its pocket. j. Replace the dust cap back into the keyhole.

WARNING: Check for proper service and emergency operation after servicing any part of chamber. Check the brake adjustment if the unit is installed on the vehicle. (Follow vehicle manufacturer instructions to adjust the brakes).

WARNING: Do Not Remove Spring Brake Chamber Clamps!

Fig 5



SECTION 5 Installation Instructions for Tandem Models

1. The pushrod must be cut to the correct length. NOTE: CAGE THE SPRING BRAKE BEFORE CUTTING THE PUSHROD ñ See Section 1

To calculate the correct pushrod length, a dimension ìBî must be measured. This dimension is the TOTAL length of the pushrod and the clevis when the brakes are fully applied. It is measured form the mounting surface of the spring brake to the center of the camshaft. See Fig. 6a and 6b. Note that the pushrod should be at 90° angles with both the slack adjuster and mounting face. Incorrect mounting is shown in Fig 8a and 8b. Pushrod Length = ìBî ñ 1.5 ñ Clevis Throat Length (Fig 7)

2. Mount the spring brake to the mounting brackets and install the jam

nut and clevis Torque: Mount Nut = 130 ft lbs. Jam Nut = 20 ft lbs.

3. Connect the proper air lines to the service and emergency ports. Attach the clevis to the slack adjuster and uncage the unit.

4. When spring brake is completely installed, put the release tool back into pocket and adjust the brakes according to the slack adjuster manufacturers instructions.

5. Check parking and service brakes for proper operation

Example: B is 6 inches The clevis throat is 1.25 inches Pushrod Length = 6 ñ 1.5 ñ 1.25 = 3.25 inches

WARNING: For Correct alignment and efficient operation of the spring brake, the pushrod needs to have correct length. WARNING: Block wheels before working under vehicle

Fig 6a

Fig 6b

Fig 7

Fig 8a Fig 8b



SECTION 6 Mounting Instructions for Tandem Models

1. Make sure brake is caged ñ See Section 1

2. Inspect the mounting brackets to make sure they are free

from debris, burrs, cracks, and to make sure the surface is flat. (Figure 9)

3. Always mount unit directly to the mounting bracket. DO

NOT insert spacers, washers, shims, or reinforcing plate between the brake housing and the mounting bracket. (Figure 10)

WARNING: For Correct alignment and efficient operation of the spring brake, the pushrod needs to have correct length. WARNING: Block wheels before working under vehicle

Fig 9

Fig 10



Notes:

Service and Installation Instructions - TTT · Service Bulletin Air Brake Chambers SPRING BRAKES ñ...

Documents

Transcript of Service and Installation Instructions - TTT · Service Bulletin Air Brake Chambers SPRING BRAKES ñ...