BENDIX DD-3-SD-3 SAFETY ACTUATORS Manuel - Page 3

Parcourez en ligne ou téléchargez le pdf Manuel pour {nom_de_la_catégorie} BENDIX DD-3-SD-3 SAFETY ACTUATORS. BENDIX DD-3-SD-3 SAFETY ACTUATORS 6 pages. Safety actuators

Imprimer la page

RELEASING (SD-3

ACTUATOR)

™

To release the park application, air pressure in excess of 40

psi must be applied at the lock port and a service application

slightly greater than the locked-in application made. For

practical purposes, a full reservoir application should be made

and held for 5 seconds to produce sufficient forward motion

of the shaft to allow disengagement of the lock mechanism.

Various control systems are used to achieve the proper

sequence of control signals. Bendix brochure "Off Highway

Vehicle Braking System" (BW 1283) explains one such

system.

PREVENTIVE MAINTENANCE

GENERAL

Depending on experience and type of operation, the drain

slot in the actuator non-pressure plate should be checked

and cleaned of any restricting road grime, mud, ice, snow,

etc. Check or replace actuator boot if loose on the push

rod or if worn.

Brake should be adjusted at the slack adjuster as is

customary with standard brake chambers. Push rod travel

should be as short as possible without brakes dragging.

Excessive travel not only shortens the normal service life of

the diaphragm but gives slow braking response and wastes

air.

Push rod to slack adjuster alignment should be checked in

both the applied and released positions. The rod should

move out and return promptly without binding.

Check the angle formed by the slack adjuster arm and

push rod. It should be 90° or greater when the actuator is

in the applied or released position when brakes are properly

adjusted.

EVERY MONTH, 300 OPERATING HOURS, OR AFTER

8000 MILES

Check push rod travel, alignment and nuts for tightness.

Check hoses. (See slack adjuster for adjustment.)

Check for proper operation.

EVERY 3 MONTHS, 900 OPERATING HOURS, OR 25,000

MILES

When grease fitting is provided, grease with Lubriplate

"Aero" lubricant.

EVERY 12 MONTHS, 3600 OPERATING HOURS, OR

100,000 MILES

Disassemble, inspect diaphragms and rubber parts, rod,

springs, and non-pressure plate. Replace all parts worn or

damaged. Check for proper operation before placing vehicle

in service.

REMOVING AND INSTALLING

Block and hold the vehicle by some means other than air

brakes.

REMOVING DD-3

ACTUATOR

™

With the actuators in a released position, disconnect the

air lines to the service and auxiliary ports. Move the park

control valve to the park position which will exhaust the air

from the lock port. Disconnect the lock port line. Remove

yoke pin and back off slack adjuster. Remove mounting

nuts, then actuator.

REMOVING SD-3

™

ACTUATOR

If the SD-3

™

actuator is mounted on a vehicle with its own

air supply, the parking control should be placed in the release

position with the air system completely charged. Disconnect

the service port line. Move the park control valve to the park

position and disconnect the lock line. Remove the actuator

as above.

If the SD-3

actuator is mounted on a trailer, with no air

™

supply present and in the applied position, completely drain

trailer reservoir. Remove delivery and lock port lines from

actuator. Release force from actuator by backing off slack

adjuster or mounting nuts or both. Remove actuator.

INSTALLING

IMPORTANT - DD-3

and SD-3

™

installed with the exhaust check valve down and the drain

slot pointing down.

Mount actuator to mounting bracket and tighten securely.

Fasten actuator push rod yoke to slack adjuster with yoke

pin. Lock yoke pin with cotter pin. The angle formed by the

push rod and slack adjuster arm should be greater than

90°.

Connect air lines to actuator. Take care that the correct line

is installed in the correct port.

Adjust brakes.

DISASSEMBLY

1. Clean actuator exterior of all road grime and mark in

such a way so it can be assembled in the same manner.

2. Remove yoke and yoke lock nuts.

3. Remove splash guard, boot, felt breather, and gasket.

4. Remove auxiliary and service clamping ring nuts and

bolts.

safety actuators must be

™