BENDIX MC-12 MODULATOR CONTROLLER ASSY Guía para resolver problemas descargar pdf (Pagina 64)

More info: visit www.bendix.com 1-800-AIR-BRAKE (1-800-247-2725)

TEST 6

Dual circuit system integrity check (emergency braking)

and/or Automatic application of the parking brake and /or

Tractor protection valve operation

Full pressure, engine stopped, parking brakes

released

1. Drain the front axle or secondary reservoir to 0 psi.

A. The rear axle or primary reservoir should retain most of

its pressure.

B. On combination vehicles, the trailer air system should

remain charged.

C. Tractor and trailer brakes should not apply automatically.

2. With no air pressure in the front axle reservoir make a brake

application.

A. Rear axle brakes should apply and release when

application is released.

B. On combination vehicles the trailer brakes should also

apply and release when application is released.

C. The stop lamps should light and go off when the

application is released.

3. Optional “Pop” Pressure Vehicle Test Procedure

[Note: Bendix is not aware of any federal legislation that speciﬁ es

the pressure at which the YELLOW parking brake control valve

must automatically “trip” to apply the vehicle parking brakes.

This includes the Federal Motor Carrier Safety Regulations

(FMCSR) for in-use vehicles, the CVSA out-of-service criteria,

and the Federal Motor Vehicle Safety Standards (FMVSS) for

newly manufactured vehicles. Although the “trip” pressure for

the parking brake control valve is not stipulated for in-use or

newly manufactured vehicles, a parking brake control valve “trip”

pressure of 20-40 psi is currently (02/2009) speciﬁ ed as part of

the Commercial Driver License in the CDL Manual. The CDL

Manual is not consistent with the regulations cited above. See

Bulletin TCH-03-051.]

A. Install an accurate “shop standard” pressure gauge in the

secondary service reservoir.

B. Build pressure in the service reservoirs until the

compressor cut-out is reached, shut the engine off.

C. Open the manual drain valve on the primary service

reservoir allowing the reservoir to drain completely.

D. Open the secondary reservoir’s manual drain valve

creating a bleed rate of approximately 20-50 psi/min.

E. Verify that the parking control automatically “pops”.

4. For Towing Vehicles Only - Test the tractor protection valve

feature

A. Charge the air system to governor cut-out.

B. Disconnect the service or control (blue) line to the trailer.

C. Take care to restrain the service coupling and direct ﬂ ow

safely away while making and holding a full service brake

application via the foot valve.

D. As the service application is vented through the open

gladhand the service system pressure drops until the

tractor protection control (red) valve trips shutting off the

leak through the open coupling.

E. Record the pressure in the service reservoirs. Disconnect

the trailer supply coupling to verify that the supply or

emergency (red) coupling has been vented to atmosphere,

thereby activating the trailer emergency feature.

5. Close the drain cocks, recharge system and drain rear axle,

primary reservoir to 0 psi.

A. The front axle reservoir should retain most of its pressure.

B. On combination vehicles the trailer air system should

remain charged.

6. With no air pressure in the rear axle reservoir, make and

release a brake application.

A. Front axle brakes should apply and release.

B. On combination vehicles the trailer brakes should also

apply and release.

C. If the vehicle is equipped with a spring brake modulating

valve, typically found on trucks, towing trucks and buses,

the rear axle brakes should also apply and release by

exhausting spring brake air.

Make all necessary repairs before proceeding; See

checklist 6 for common corrections.

CHECKLIST 6

If the vehicle fails to pass the tests outlined, then

check the following components for leakage and

proper operation:

1. Fittings

2. Kinked hose or tubing

3. Pressure protection valves

4. Double check valves

5. Tractor protection valve

6. Tractor protection control valve

7. Parking control valve

8. Relay valves (antilock modulators)

9. Trailer spring brake control valve

10. Inverting relay spring brake control valve (optional) straight

trucks and buses

Retest to verify proper operation of all items repaired

or replaced.

Air Brake System Troubleshooting Tests (continued)

1 2 ... 59 60 61 62 63 64 65 66 67 68 69 70

Comentarios a estos manuales

Sin comentarios

BENDIX MC-12 MODULATOR CONTROLLER ASSY Guía para resolver problemas Pagina 64

Comentarios a estos manuales

Relacionado con productos y manuales para Modulador BENDIX MC-12 MODULATOR CONTROLLER ASSY