SECTION air supply system + WARNING: + NOTE: GENERAL DESCRIPTION COMPRESSED AIR RESERVOIRS / 1.

Transcription

1 / JA14 SECTION GENERAL DESCRIPTION See Figure 1 for a schematic diagram of the. See the Nova LFS parts manual for a detailed schematic of the. The function of the vehicle s is to provide clean, dry compressed air to different air systems at a pressure of between 110 and 135 psi (758 and 931 kpa). Compressed air s provide an adequate supply of compressed air that is available for the immediate operation of brakes, the pneumatic suspension system and other pneumatic equipment, leveling and kneeling, doors and other pneumatic equipment. Compressed air s are also used to cool down and condensate oil and water vapors contained in compressed air. The configuration of the supply system may vary depending on the type of air dryer installed on the vehicle. The main part of this section addresses the supply system components that are common to all types of air dryers. For the general description and the operation of the relative to the air dryer actually installed, see the corresponding module at the end of this section: module A: Supply system with a Haldex single air dryer. module B: Supply system with a Haldex double air dryer. module C: Supply system with a Bendix air dryer. module D: Supply system with a SludgeBraker. module E: Supply system with an SKF air dryer. See section : air dryer and condenser in this manual for information on the air-drying system. COMPRESSED AIR RESERVOIRS PURGING THE COMPRESSED AIR RESERVOIRS For safe and proper use, the pneumatic components of the vehicle must be supplied at all times with clean, dry compressed air. The pneumatic circuits are designed for this purpose, by the installation of components, such as the air dryers, Expello type purge valves, as well as others. However, these components may fail and/or become less efficient. It is therefore recommended to frequently perform a manual purge of the compressed air s, in order to eliminate any contaminants, which can remain there and to verify the proper functionality of the air dryer. See section : air dryer and condenser for additional information on this system. Transit authorities should determine the frequency of these manual purges according to the operating conditions of the vehicle (temperature, relative humidity, etc.), and the performance of the system. To prevent problems, the manufacturer recommends that manual purges be performed at regular intervals. The following procedure indicates how to remove all the liquid from the s without completely purging the air from the system. + WARNING: To avoid injury to the eyes, always wear eye protection at all times during maintenance or repair of the vehicle. + WARNING: Remove air pressure from the system completely before disconnecting any component. Air under pressure can cause serious bodily injuries. GENERAL MAINTENANCE All compressed air assembly bolts should be checked regularly for looseness and should be tightened as needed. Check air s for corrosion or other damage. Replace any air that has been weakened by such damage. Air s may be cleaned inside and out with steam or hot water. + WARNING: Park the vehicle on a level surface. Block the wheels to prevent any unexpected movement of the vehicle. Support the vehicle underneath with stands. See section 18: hoisting and towing in this manual for more information on lifting the vehicle.

2 2011JA14 2 / Start with the supply. With the system pressure at its operating value, open the purge valve momentarily and verify for any trace of humidity, in the form of spray or droplets. a. No presence of humidity: close the valve. b. Presence of humidity: open the purge valve repeatedly during several seconds, until no more humidity is emitted. Wait for several seconds between two of the openings to allow the humidity to return inside the purge valve. When there is no further trace of humidity, close the purge valve and go to the next. 2. If, during the procedure to remove humidity, the air pressure falls to zero, leave the valve open for several seconds, then close it again. It is unlikely that the supplementary humidity has been purged while leaving the valve open. 3. Repeat this procedure on each of the compressed air s. 4. If humidity is found in the system each day: a. Verify the system for leaks; b. Replace the air dryer cartridge; c. Verify if the proper components are installed on the vehicle. Compressed air LINES Flexible and nylon lines, as well as a copper line (coil), are installed on the vehicle. All fittings should be checked for leaks at each 5,000 mi (8,000 km) at least and they should be tightened or replaced as needed. Any line that is scratched, worn or kinked must be replaced. See section 99: General practices in this manual for additional information. COPPER LINES (cooling coils) When replacing the coils, make sure the replacement line is free from burrs, cuts and dirt. Clean by blowing compressed air. Any metal or dirt particle may seriously damage the sealing contact seats of pneumatic control units. A new line must have the same dimensions as the old one it replaces. Always use a new compression ring when replacing a line. When tightening tube fitting bolts, apply torque values indicated in Table 1 to ensure a tight fit. A leak will result if too much, or insufficient torque is applied. Apply S.A.E. 10 oil to ball sockets, to tubes and to external thread, then tighten to minimum torque and check for leaks. If there is a leak, back off the tube nut by about half a turn, then tighten to more than minimum torque. FLEXIBLE LINES + CAUTION: The path of flexible lines has been carefully designed, in order to minimize the risk of damage. This path should never be modified for any reason whatsoever. Line damages may result if a line is installed at any location other than the original Nova Bus location. NYLON Compressed air LINES Each flexible-line circuit is identifiable by its own particular color: Green: Primary braking and air dryer circuits; Red: Secondary braking circuit; Brown: Parking and emergency braking circuit; Blue: Air suspension circuit; Black: Doors circuit; hose diameter torque value DRY HUMID ¼ in. 6.4 mm 105 ±45 lb-in (12 ±5 N m) 40 ±10 lb-in (4.5 ±1 N m) 3 / 8 in. 9.5 mm 155 ±70 lb-in (17.5 ±8 N m) 40 ±10 lb-in (4.5 ±1 N m) ½ in mm 17.5 ±4.5 lb-ft (23.5 ±6 N m) 8.5 ±0.5 lb-ft (11.5 ±0.5 N m) 5 / 8 in mm 25 ±8 lb-ft (34 ±11 N m) 9.5 ±0.5 lb-ft (13 ±0.5 N m) ¾ in. 19. mm 31 ±6 lb-ft (42 ±8 N m) 15.5 ±2.5 lb-ft (21 ±3 N m) 1 in mm 35 ±5 lb-ft (47.5 ±7 N m) 17.5 ±2.5 lb-ft (24 ±3 N m) Table 1 Hose Diameter and Respective Torques

3 / JA14 + CAUTION: Nylon compressed air lines should be installed only at locations where nylon lines have been previously used. Nylon lines should never be installed at locations where temperatures may exceed 200 F (93 C). Replacement 1. Cut the correct diameter nylon line to the required length. Replacement lines must be of an appropriate length and diameter and should be fitted with end connectors. No special tools are required to install the end connectors. 2. Place the nut and then the sleeve at the end of the line. 3. Insert the stainless steel liner inside the line, pushing until the flange comes in contact with the line s cut end. 4. Place the adjacent fitting on the cut end of the line and tighten the nut until only one thread is still visible. 5. Install the other fitting at the other end of the nylon line. Make sure the line has no kinks after it has been installed on the vehicle. Avoid using a welding torch near nylon compressed air lines. Spare lines should be stored in a clean location with their ends plugged. 3. Connect a manometer (AG or equivalent that reads psi [ kpa]) on the rear supply drain, accessible through the rear engine compartment door. + CAUTION: If there is a check valve on the purge valve, make sure the manometer reads the pressure. 4. Supply the pneumatic system with an exterior compressed air supply. Connect the source to the left rear towing coupling. See Figure Pull the main door control valve up on the Operator s side console and check that the door control lever is in the closed position. 6. Release the parking brake and install a block of wood on the brake pedal to keep it fully applied. 7. When the system pressure reaches between 110 and 135 psi (758 and 931 kpa), spray soapy water on all pneumatic system component connections located under the vehicle (e.g. air dryer, ping tank, coil, etc.). See Figure 2. + CAUTION: This step validates the airtightness of the pneumatic system for the components in the rear portion of the vehicle. Make sure the left rear towing coupling valve remains open to maintain the air supply. NORMAL CONDITION OPERATIONAL TEST When any symptom, such as a slow brake application, or slow brake release, indicates a plugged or fouled compressed air line, disconnect the suspected tube or line at both ends and blow air through it to make sure that it is not completely plugged up. Check the tube or line, looking for any partial obstruction caused by dents or wrinkles. If any of those defects is found, the tube or line should be replaced. LEAK TEST Perform a leak test to ensure that there are no air leaks in the entire pneumatic system. 1. Ensure that the electrical system is off. 2. Ensure sure that the s purge valve is fully open. See Figure 1. Figure 1 - Location of Supply Reservoir Drain Valve

4 2011JA14 4 / SINGLE OR tandem CONFIGURATION Figure 2 - Left Rear Tow Coupling 8. Identify and repair any air leaks. 9. Repeat step #7, to ensure that the system pressure reaches between 110 and 135 psi (758 and 931 kpa), then shut off the external air supply. 10. Wait two minutes for the system pressure to stabilize. 11. Record the air pressure indicated by the manometer. 12. Wait 15 minutes and take another air pressure reading. Compare it with the reading taken previously. The difference should be less than or equal to 5 psi (35 kpa). This step validates the airtightness of the pneumatic system inside the vehicle (s, door mechanisms, etc.) and various sections under the vehicle (driver s seat, brake pedal, ABS valves, axle bellows, etc.) 13. If the pressure has dropped by more than 5 psi (35 kpa), check, identify and repair any air leaks (spraying soapy water as required.) Check the valves, s, hoses, connections, etc. It is possible that some valve drains have slight leaks (e.g. the R14 or R15 relay valve and the E-10 brake valve.) 14. Repeat these steps until results are satisfactory. Sometimes, a leak can be corrected by just tightening the fitting. If tightening will not stop the leak, new fittings or a new flexible line or new nylon line must be installed. Air Pressure Gauges See Figure 3. The air pressure gauge located in the instrument panel is connected by an air line to the primary supply tank (green hand) and by another line to the secondary supply tank (yellow hand). The vehicle should never start moving before indicated air pressure reaches at least 80 psi (552 kpa). When pressure falls below 80 psi (552 kpa) the low air indicator light turns on and the low pressure alarm sounds. The operator must stop the vehicle immediately and determine the cause of the pressure loss. The pressure indicator must be checked regularly with a precise test gauge. Replace the gauge by a new unit if reading differences reach or exceed 4 psi (28 kpa). Calibration Checking Check at 120 and 150 psi (827 and 1034 kpa) with increasing pressure. Check at 60 and 0 psi (414 and 0 kpa) with decreasing pressure. The hands must be positioned within the limits shown on the dial [4 psi (28 kpa)]. Lightly tap the gauge when checking at 60, 120, and 150 psi (414, 827 and 1034 kpa). Both hands must return to 0 psi (0 kpa) without having to tap on the gauge. Low-Pressure Warning Switches Low-pressure warning switches are safety devices designed to automatically trigger a warning signal whenever the compressed air system pressure falls below a pre-determined safe limit for the braking system operation. Each low-pressure warning switch is, in fact, a pneumatically controlled switch within an electrical circuit that automatically controls an indicator light and a warning horn.

5 / JA DO NOT OPERATE BELOW 80 PSI AIR REAR HAND (YELLOW) FRONT HAND (GREEN)REAR front view rear view Figure 3 -Air Pressure Gauge PREVENTIVE MAINTENANCE 1. Every 300 hours or 8,000 mi (12,800 km), check electrical connections. 2. Each year or every 100,000 mi (160,000 km), replace worn or damaged parts. tests Operational Test The low-pressure warning switch operation can be checked by reducing the system pressure while making sure that contacts close when the tank pressure is between 74 psi (510 kpa) and 86 psi (593 kpa). Contacts are closed when the indicator light is on and the buzzer sounds. Leak Test The low air pressure switch cover is equipped with a small vent that allows for checking the membrane condition. Cover the vent with a film of soapy water. If bubbles appear, indicating a leak, this means that the membrane is not airtight and the pressure switch must be replaced. Replacement Removal Release the system air pressure. Disconnect wires from the switch terminals and remove the switch from the compressed air line. Installation Install the switch in the compressed air line. Connect wires to the switch terminals. Let the air pressure rise in the system and proceed to the switch test as previously described under the heading normal condition operational tests. Anti-return (CHECK) VALVE The spring-type anti-return valves allow the compressed air to circulate in only one direction. The valves are located in the air lines between the pressure-maintaining valve and the suspension air. The anti-return valves should be removed, disassembled and cleaned regularly. These check valves should be replaced if they show evidence of wear. When installing a valve, make sure that the arrow on the cap is oriented toward the.

6 2011JA14 6 / SAFETY VALVE See Figure 4. The safety valve protects the air braking system whenever the pressure exceeds 150 psi (1034 kpa). When this pressure is reached, the safety valve opens to release excess pressure. It automatically shuts as soon as the pressure is reduced. SEQUENCE VALVE See Figure 5. The sequence valve allows the filling of the accessory when the primary and the secondary s are pressurized at 65 psi (448 kpa). Preventive MAINTENANCE Inspect the safety valve periodically and check for leaks by wetting the discharge port with soapy water. A leak is acceptable if it forms one bubble of no more than 1 in. (25 mm) in diameter, in no less than 5 seconds. Once a year, or every 50,000 mi (80,000 km), whichever occurs first, the safety valve should be disassembled and cleaned with solvent. The safety valve cannot be adjusted. The sequence valve is located on the accessory. Preventive MAINTENANCE It is recommended to check the valve operation every 6 months or 30,000 mi (48,000 km), whichever occurs first, by connecting a test gauge to the distribution line and monitoring the closing valve pressure, while air is being expelled from the distribution system. Make the necessary adjustments. Once a year or every 100,000 mi (160,000 km), whichever occurs first, disassemble the valve and clean all its parts. Replace all rubber parts showing signs of wear. 1 adjustment cap spring Piston 7 nut Piston plug grommet inlet port grommet body valve stem valve spring 1. STEM 2. BALL-CHECK VALVE 3. CASING 4. SPRING CAGE 5. DISCHARGE PORT 6. SPRING CUP 7. SPRING valve guide Figure 4 - Safety Valve Figure 5 - Sequence Valve

7 / JA14 TESTS Bench Test 1. The valve must be connected with lines providing an adjustable air supply and a small distribution volume. 2. Connect precision gauges to both lines. 3. Increase the supply pressure until both gauges indicate the same pressure. 4. Shut off the supply line and drain the distribution line. 5. Register the supply pressure as the valve closes, as indicated on the distribution line gauge. Leak Test With a supply pressure of about 100 psi (690 kpa), coat the adjusting cap slot and adjacent area with a soapy solution. Drain air from the distribution line and check again for leaks. No leaks are allowed throughout this procedure. Adjustment Pressure adjustment is determined by the tension of the spring above the piston. 1. Loosen the locking nut and turn the cap clockwise to increase the pressure. Turn it counterclockwise to decrease it. 2. Tighten the lock-nut. REPLACEMENT 1. Block or immobilize the vehicle by means other than the compressed air brakes. 2. Completely drain the. 3. Disconnect all compressed air lines from the valve. 4. Remove fastening bolts and remove the valve. 5. Repeat these steps in reverse order for reinstallation. INSPECTION 1. Immerse plastic and metallic parts in solvent for cleaning. 2. Rubber parts must also be cleaned. 3. Inspect all parts and check for wear and damages. 4. Inspect springs and check for cracks, corrosion and distortion. 5. Replace all rubber parts showing cracks and signs of wear and damage. ASSEMBLY 1. Repeat the disassembly procedure steps in the reverse order. 2. Coat rubber parts and metal-to-metal contact surfaces with a silicone-based grease. Air strainer See Figure 6. An optional single air strainer is used for the vehicle s compressed air lines. The air filter is located on the accessory equipment. The filter should be removed, disassembled and cleaned annually. Replace the seals, if necessary. Immerse the filtering material in solvent. Dry out the material and reassemble the filter. Tighten the bushings. overhaul DISASSEMBLY 1. Loosen the lock-nut. 2. Remove the adjustment cap, then the lock-nut. 3. Remove the spring, the piston and the valve from the body. 4. Remove the valve, the retainer and the spring from the stem. 5. Rotate the piston and fully depress the inlet valve stem. This will loosen the piston plug with its o-ring from the piston center. 6. Remove the piston o-ring. air strainer (optional) Figure 6 - Installation of the Optional Air Strainer on the Accessory Reservoir

8 2011JA14 8 / Supply valves These optional valves for compressed air lines are used primarily to keep the pneumatic suspension system inflated during long periods when the vehicle is not operating. The valve installed at the supply may be used to check the air pressure within this. A tire gauge calibrated to 150 psi (1034 kpa) may be used. When an external compressed air supply is required, make sure that the supply source is clean before connecting it to the vehicle s pneumatic system. General system maintenance Test methods for adjusting and maintaining brake system components are described under individual categories within this section. The entire pneumatic system should be checked for leaks on a regular basis. With the engine stopped and the brakes released, check the air pressure falling rate on the air pressure gauge located in the instrument panel. This rate should not exceed 5 psi (35 kpa) for a three-minute period. Perform the same test with the motor stopped, but with the brakes firmly on. The rate of the pressure drop should not exceed 5 psi (35 kpa) for a three-minute period. If the leak is excessive, leak tests should be carried out on air brake couplings and on each air brake control unit. PREVENTIVE MAINTENANCE See Table 2. The actual operational activities of the buses covered by this maintenance manual vary widely. Under these circumstances, it is impossible to establish maintenance intervals, whether time or mileage. Therefore, the intervals given in the preventive maintenance table must be used in relation to the operational conditions to which a particular bus is subjected. The given intervals are the manufacturer s recommendations and must be considered as maximum periods. It is preferable to maintain the vehicles using shorter intervals than shown, rather than longer intervals. Section : braking system can provide information on the maintenance of the components of the air braking system. +CAUTION: This table is not an exhaustive list of all maintenance required; it is preferable to conduct more frequent inspections. Each time an assembly is removed and disassembled for maintenance, it is recommended to replace all grommets, seals, O-rings, etc., and any other worn or damaged part.

9 PREVENTIVE MAINTENANCE TABLE / 9 COMPONENTS INTERVAL( 1 ) ) INTERVAL(1) 2011JA14 Transducers Safety valve a. 300 hours - 12,000 km (8,000 mi) a. Check electrical connections. b. 3,600 hours - 160,000 km (100,000 mi) b. Remove, clean, inspect. 6 months - 80,000 km (50,000 mi) Remove, disassemble, clean, inspect. Compressed air line 8,000 km (5,000 mi) Check for leaks; tighten as needed. Purge valve 1,800 hours - 80,000 km (50,000 mi) - 6 months Remove, disassemble, clean, inspect. Pressure-maintaining valve 3,600 hours - 160,000 km (100,000 mi) - 1 yr Remove, clean, inspect. Inversing valve 3,600 hours - 160,000 km (100,000 mi) - 1 yr Remove, clean, inspect. Interlock Valve 3,600 hours - 160,000 km (100,000 mi) - 1 yr Remove, clean, inspect. Air compressor See Note 2. Governor Clean carbon deposits from valves and discharge lines. Check fastening bolts and tighten as needed. Check lines for leaks. a. 500 hours - 24,000 km (15,000 mi) a. Clean or replace the filters. b. 3,000 hours - 160,000 km (100,000 mi) - 1 yr b. Remove, disassemble, clean, inspect, adjust. (1) When two or more intervals are mentioned, the operation must be performed at the first interval. (2) Depending on how severe the operating conditions. Table 2 - Preventive Maintenance

10 2011JA14 10 / TROUBLESHOOTING GUIDE PROBABLE CAUSE SLOW PRESSURE ACCUMULATION IN TANKS 1. Dirty air filter. 2. Air leak. 3. Faulty compressor. 4. Open or leaking drain tank valves. 5. Faulty compressor governor. CORRECTIVE ACTION 1. Clean or replace. 2. Find and repair. 3. Repair (refer to the manufacturer s manual). 4. Shut off, repair or replace. 5. Repair or replace. ABOVE NORMAL AIR PRESSURE 1. Faulty gauge. 2. Out-of-adjustment or faulty governor. 3. Obstructed line between governor and compressor. 1. Replace. 2. Adjust, repair or replace. 3. Remove obstruction or replace line. QUICK LOSS OF PRESSURE AFTER ENGINE SHUTDOWN (BRAKES UNAPPLIED) 1. Leaking lines or connection fittings. 2. Compressor discharge valve or one-way pressure-retaining valve worn or leaking. 3. Leaking governor. 4. Leaking brake-applying valve. 5. Open or leaking drain tank valve. 6. Faulty parking brake control valve. 1. Repair or replace. 2. Repair or replace. 3. Repair or replace. 4. Repair or replace. 5. Shut off, repair or replace. 6. Repair or replace.. QUICK LOSS OF PRESSURE AFTER ENGINE SHUTDOWN (BRAKES FULLY APPLIED) 1. Leaking brake chamber. 2. Leaking braking valve. 3. Faulty brake line. 4. Leaking brake chamber hoses. 5. Faulty quick-release valve. 6. Faulty normal duty braking relay valve. 7. Faulty parking brake control valve. 1. Replace. 2. Repair or replace. 3. Repair or replace. 4. Repair or replace. 5. Clean or replace membrane. 6. Repair or replace. 7. Repair or replace. AIR BLEEDING OUT FROM SAFETY VALVE 1. Out-of-adjustment safety valve. 2. Out-of-adjustment governor. 1. Adjust. 2. Adjust. Table 3 - Troubleshooting Guide

11 / 11 SECTION A (haldex single) 2011JA14 GENERAL DESCRIPTION See Figure 1A for a schematic diagram of the air-drying system for the Nova LFS vehicle equipped with a Haldex single air dryer. See the Nova LFS parts manual for a detailed schematic of the. The for a Nova LFS vehicle, equipped with a Haldex single air dryer, is comprised of: An air compressor, installed on the engine, that compresses the air and supplies the pneumatic system; An integrated or external air dryer governor that controls the air pressure in the system; A ping tank (optional) that absorbs the shock waves of air compression by the compressor, thus reducing the noise produced by this shock; Copper coils that cool the compressed air; A condenser with a purge valve that removes oil and other contaminants from the air before they can enter the air dryer; An air dryer with a purge tank that removes any remaining contaminants from the compressed air; A supply that stores the compressed air; A primary, a secondary, an accessory and an emergency that serve the different pneumatic systems; An external air supply connector and a tow connector (an additional air supply connector may be installed). OPERATION The compressor compresses the air and supplies the pneumatic system. The governor integrated in the air dryer automatically controls the air pressure in the system and commands the compressor by activating or deactivating the compressor discharge mechanism whenever the minimum or maximum pressure of the supply is reached. The ping tank (optional), located between the compressor and the cooling coils, absorbs the shock produced by the alternating compression cycle of the compressor and reduces the noise associated with this shock. The air then passes through the cooling coils. These cooling coils lower the temperature of the compressed air, in order to start the condensation of the humidity vaporized in the air by the compressor. The air from the compressor or an external source is then treated by the condenser to extract most of the impurities in the air. The compressed air is then treated by the air dryer that removes the humidity. Whenever the maximum pressure of the supply circuit is reached, the contaminants in the dryer are purged and the humidity remaining is expelled by the dry air from the purge tank that recirculates in the dryer. See section : air dryer and condenser in this manual for additional information on the airdrying system. Once dry and devoid of contaminants, compressed air is sent to the supply, which acts as an air reserve for the other components of the pneumatic system. The contaminants accumulated in the supply can be purged by a manual purge valve installed at one end of the, or electronically by an optional automatic purge valve. The automatic valve purges the contaminants approximately every five minutes. A 50 W element maintains the temperature of the valve between 45 ºF and 105 ºF (7 ºC and 41 ºC) in order to prevent freezing of the water during the winter season. Compressed air is then sent in a prioritized sequence to the primary, the secondary and to the emergency. Before reaching the accessory, the air passes through a sequence valve, which delays the movement of air to the accessory in order to prioritize the pressurizing of the s for the braking system. Once the pressure in the system reaches 448 kpa (65 psi), the sequence valve opens and allows the accessory to be filled. An anti-return valve, also installed at the entrance to the accessory, prevents the depressurization of the in case of a major leak in the supply system. A safety valve expels any overproduction of compressed air in case of a breakdown of the air flow control within the system. This valve expels the compressed air once the pressure is above that required for normal operation of the system. If the pressure falls below this value, the safety valve closes, in order for the system to continue to be fed with compressed air. Finally, an optional towing connector is installed to supply the brakes and other pneumatic accessories during a towing operation.

12 2011JA14 12 / Réservoir de purge auto Purge optional Condenser air dryer supply primary coils ping tank (optional) secondary Compressor governor external or integrated emergency accessory check valve air supply connector automatic purge valve manual purge valve safety valve sequence valve COMPRESSED AIR (PRESSURE): 110 to 135 psi (758 to 931 kpa) Air is: a. compressed by the compressor, whenever it receives a signal from the governor b. cooled as it passes through the copper coils c. expelled with most of the water and impurities in the condenser d. filtered and dried by the air dryers e. accumulated in the supply, feeding in turn the primary, the secondary, the emergency, and the accessory. Figure 1A - Schematic Diagram of the Pneumatic Supply System with Haldex Single Air Dryer

13 / 13 SECTION B (haldex double) 2011JA14 GENERAL DESCRIPTION See Figure 1B for a schematic diagram of the air-drying system for the Nova LFS vehicle equipped with a Haldex double air dryer. See the Nova LFS parts manual for a detailed schematic of the. The for a Nova LFS vehicle, equipped with a Haldex double air dryer, is comprised of: An air compressor, installed on the engine, that compresses the air and supplies the pneumatic system; An external air dryer governor that controls the air pressure in the system; A ping tank that absorbs the shock waves of air compression by the compressor, thus reducing the noise produced by this shock; Copper coils that cool the compressed air; A condenser with a purge valve that removes oil and other contaminants from the air before they can enter the air dryer; A wet tank with automatic purge valve, where the air is recondensed; Two air dryers mounted in tandem and two purge tanks that remove any remaining contaminants from the compressed air; A supply that stores the compressed air; A primary, a secondary, an accessory and an emergency that serve the different pneumatic systems; Two external air supply connectors and a tow connector. OPERATION The compressor compresses the air and supplies the pneumatic system. The governor integrated in the air dryer automatically controls the air pressure in the system and commands the compressor by activating or deactivating the compressor discharge mechanism whenever the minimum or maximum pressure of the supply is reached. The ping tank, located between the compressor and the cooling coils, absorbs the shock produced by the alternating compression cycle of the compressor and reduces the noise associated with this shock. The air then passes through the cooling coils. These cooling coils lower the temperature of the compressed air, in order to start the condensation of the humidity vaporized in the air by the compressor. The air from the compressor or an external source is then treated by the condenser to extract most of the impurities in the air. The air is then stored and recondensed in the wet tank before passing to the air dryer. The compressed air is then treated by the one of the air dryers, which removes the humidity. Whenever the maximum pressure of the supply circuit is reached, the contaminants in the dryer are purged and the humidity remaining is expelled by the dry air from the purge tank that recirculates in the dryer. See section : air dryers and condenser in this manual for additional information on the air-drying system. Once dry and devoid of contaminants, compressed air is sent to the supply, which acts as an air reserve for the other components of the pneumatic system. The contaminants accumulated in the supply can be purged by a manual purge valve installed at one end of the, or electronically by an optional automatic purge valve. The automatic valve purges the contaminants approximately every five minutes. A 50 W element maintains the temperature of the valve between 45 ºF and 105 ºF (7 ºC and 41 ºC) in order to prevent freezing of the water during the winter season. Compressed air is then sent in a prioritized sequence to the primary, the secondary and to the emergency. Before reaching the accessory, the air passes through a sequence valve, which delays the movement of air to the accessory in order to prioritize the pressurizing of the s for the braking system. Once the pressure in the system reaches 448 kpa (65 psi), the sequence valve opens and allows the accessory to be filled. An anti-return valve, also installed at the entrance to the accessory, prevents the depressurization of the in case of a major leak in the supply system. A safety valve expels any overproduction of compressed air in case of a breakdown of the air flow control within the system. This valve expels the compressed air once the pressure is above that required for normal operation of the system. If the pressure falls below this value, the safety valve closes, in order for the system to continue to be fed with compressed air. Finally, a tow connector is installed to supply the brakes and other pneumatic accessories during a towing operation.

14 2011JA14 14 / purge tank air dryer Condenser wet tank supply air dryer primary coils ping tank purge tank secondary Compressor external governor emergency accessory COMPRESSED AIR (PRESSURE): 110 to 135 psi (758 to 931 kpa) auto purge optional check valve air supply connector automatic purge valve manual purge valve safety valve sequence valve Air is: a. compressed by the compressor, whenever it receives a signal from the governor b. cooled as it passes through the copper coils c. expelled with most of the water and impurities in the condenser d. recondensed in the wet tank e. filtered and dried by the air dryer (the purge tank eliminates humidity from the air dryer) f. accumulated in the supply, feeding in turn the primary, the secondary, the emergency, and the accessory. Figure 1B - Schematic Diagram of the Pneumatic Supply System with Haldex Double Air Dryer

15 SECTION C (bendix) / JA14 GENERAL DESCRIPTION See Figure 1C for a schematic diagram of the air-drying system for the Nova LFS vehicle equipped with a Bendix air dryer. See the Nova LFS parts manual for a detailed schematic of the. The for a Nova LFS vehicle, equipped with a Bendix air dryer, is comprised of: An air compressor, installed on the engine, that compresses the air and supplies the pneumatic system; An external air dryer governor that controls the air pressure in the system; A ping tank that absorbs the shock waves of air compression by the compressor, thus reducing the noise produced by this shock; Copper coils that cool the compressed air; An air dryer that removes any remaining contaminants from the compressed air An oil separator that removes the remaining contaminants; A supply that stores the compressed air; A primary, a secondary, an accessory and an emergency that serve the different pneumatic systems; Two external air supply connectors and a tow connector. OPERATION The compressor compresses the air and supplies the pneumatic system. The governor integrated in the air dryer automatically controls the air pressure in the system and commands the compressor by activating or deactivating the compressor discharge mechanism whenever the minimum or maximum pressure of the supply is reached. The ping tank, located between the compressor and the cooling coils, absorbs the shock produced by the alternating compression cycle of the compressor and reduces the noise associated with this shock. The air then passes through the cooling coils. These cooling coils lower the temperature of the compressed air, in order to start the condensation of the humidity vaporized in the air by the compressor. The compressed air is then treated by the air dryer that removes the humidity. Whenever the maximum pressure of the supply circuit is reached, the contaminants in the dryer are purged. See section : air dryer and condenser in this manual for additional information on the airdrying system. When equipped, the air passes through an oil separator to extract the remaining dirt and oil particles before it enters the supply s. Once dry and devoid of contaminants, compressed air is sent to the supply, which acts as an air reserve for the other components of the pneumatic system. The contaminants accumulated in the supply can be purged by a manual purge valve installed at one end of the, or electronically by an optional automatic purge valve. The automatic valve purges the contaminants approximately every five minutes. A 50 W element maintains the temperature of the valve between 45 ºF and 105 ºF (7 ºC and 41 ºC) in order to prevent freezing of the water during the winter season. Compressed air is then sent in a prioritized sequence to the primary, the secondary and to the emergency. Before reaching the accessory, the air passes through a sequence valve, which delays the movement of air to the accessory in order to prioritize the pressurizing of the s for the braking system. Once the pressure in the system reaches 448 kpa (65 psi), the sequence valve opens and allows the accessory to be filled. An anti-return valve, also installed at the entrance to the accessory, prevents the depressurization of the in case of a major leak in the supply system. A safety valve expels any overproduction of compressed air in case of a breakdown of the air flow control within the system. This valve expels the compressed air once the pressure is above that required for normal operation of the system. If the pressure falls below this value, the safety valve closes, in order for the system to continue to be fed with compressed air. Finally, a tow connector is installed to supply the brakes and other pneumatic accessories during a towing operation.

16 2011JA14 16 / external governor air dryer oil separator (optional) supply primary coils secondary Compressor emergency accessory check valve air supply connector automatic purge valve manual purge valve safety valve sequence valve COMPRESSED AIR (PRESSURE): 110 to 135 psi (758 to 931 kpa) Air is: a. compressed by the compressor, whenever it receives a signal from the governor b. cooled as it passes through the copper coils c. expelled with the remaining contaminants in the oil separator d. filtered and dried by the air dryer e. accumulated in the supply, feeding in turn the primary, the secondary, the emergency, and the accessory. Figure 1C - Schematic Diagram of the Pneumatic Supply System with Bendix Dryer

17 / 17 SECTION D (sludgebraker) 2011JA14 GENERAL DESCRIPTION See Figure 1D for a schematic diagram of the air-drying system for the Nova LFS vehicle equipped with a SludgeBraker air dryer. See the Nova LFS parts manual for a detailed schematic of the. The for a Nova LFS vehicle, equipped with a SludgeBraker air dryer, is comprised of: An air compressor, installed on the engine, that compresses the air and supplies the pneumatic system; An external air dryer governor that controls the air pressure in the system; A ping tank that absorbs the shock waves of air compression by the compressor, thus reducing the noise produced by this shock; An air dryer that removes any remaining contaminants from the compressed air A supply that stores the compressed air; A primary, a secondary, an accessory and an emergency that serve the different pneumatic systems; Two external air supply connectors and a tow connector. OPERATION The compressor compresses the air and supplies the pneumatic system. The governor integrated in the air dryer automatically controls the air pressure in the system and commands the compressor by activating or deactivating the compressor discharge mechanism whenever the minimum or maximum pressure of the supply is reached. The ping tank, located between the compressor and the cooling coils, absorbs the shock produced by the alternating compression cycle of the compressor and reduces the noise associated with this shock. The compressed air is then treated by the air dryer that removes the humidity. Whenever the maximum pressure of the supply circuit is reached, the contaminants in the dryer are purged. Once dry and devoid of contaminants, compressed air is sent to the supply, which acts as an air reserve for the other components of the pneumatic system. The contaminants accumulated in the supply can be purged by a manual purge valve installed at one end of the, or electronically by an optional automatic purge valve. The automatic valve purges the contaminants approximately every five minutes. A 50 W element maintains the temperature of the valve between 45 ºF and 105 ºF (7 ºC and 41 ºC) in order to prevent freezing of the water during the winter season. Compressed air is then sent in a prioritized sequence to the primary, the secondary and to the emergency. Before reaching the accessory, the air passes through a sequence valve, which delays the movement of air to the accessory in order to prioritize the pressurizing of the s for the braking system. Once the pressure in the system reaches 448 kpa (65 psi), the sequence valve opens and allows the accessory to be filled. An anti-return valve, also installed at the entrance to the accessory, prevents the depressurization of the in case of a major leak in the supply system. A safety valve expels any overproduction of compressed air in case of a breakdown of the air flow control within the system. This valve expels the compressed air once the pressure is above that required for normal operation of the system. If the pressure falls below this value, the safety valve closes, in order for the system to continue to be fed with compressed air. Finally, a tow connector is installed to supply the brakes and other pneumatic accessories during a towing operation. See section : air dryer in this manual for additional information on the air-drying system.

18 2011JA14 18 / air dryer supply primary secondary ping tank Compressor external governor emergency accessory check valve air supply connector automatic purge valve manual purge valve safety valve COMPRESSED AIR (PRESSURE): 110 to 135 psi (758 to 931 kpa) Air is: a. compressed by the compressor, whenever it receives a signal from the governor b. filtered and dried by the air dryer c. accumulated in the supply, feeding in turn the primary, the secondary, the emergency, and the accessory. sequence valve Figure 1D - Schematic Diagram of the Pneumatic Supply System with SludgeBraker Dryer

19 SECTION E (SKF) / JA14 GENERAL DESCRIPTION See Figure 1E for a schematic diagram of the air-drying system for the Nova LFS vehicle equipped with an SKF or SKF air dryer. See the Nova LFS parts manual for a detailed schematic of the. The for a Nova LFS vehicle, equipped with an SKF air dryer, is comprised of: An air compressor, installed on the engine, that compresses the air and supplies the pneumatic system; An external air dryer governor that controls the air pressure in the system; A ping tank that absorbs the shock waves of air compression by the compressor, thus reducing the noise produced by this shock; Copper coils that cool the compressed air; A condenser that removes oil and other contaminants from the air before they can enter the air dryer; An air dryer that removes any remaining contaminants from the compressed air A supply that stores the compressed air; A primary, a secondary, an accessory and an emergency that serve the different pneumatic systems; Two external air supply connectors and a tow connector. OPERATION The compressor compresses the air and supplies the pneumatic system. The governor integrated in the air dryer automatically controls the air pressure in the system and commands the compressor by activating or deactivating the compressor discharge mechanism whenever the minimum or maximum pressure of the supply is reached. The ping tank, located between the compressor and the cooling coils, absorbs the shock produced by the alternating compression cycle of the compressor and reduces the noise associated with this shock. The air then passes through the cooling coils. These cooling coils lower the temperature of the compressed air, in order to start the condensation of the humidity vaporized in the air by the compressor. The air from the compressor or an external source is then treated by the condenser to extract most of the impurities in the air. The compressed air is then treated by the air dryer that removes the humidity. Whenever the maximum pressure of the supply circuit is reached, the contaminants in the dryer are purged. See section : air dryer and condenser in this manual for additional information on the airdrying system. Once dry and devoid of contaminants, compressed air is sent to the supply, which acts as an air reserve for the other components of the pneumatic system. The contaminants accumulated in the supply can be purged by a manual purge valve installed at one end of the, or electronically by an optional automatic purge valve. The automatic valve purges the contaminants approximately every five minutes. A 50 W element maintains the temperature of the valve between 45 ºF and 105 ºF (7 ºC and 41 ºC) in order to prevent freezing of the water during the winter season. Compressed air is then sent in a prioritized sequence to the primary, the secondary and to the emergency. Before reaching the accessory, the air passes through a sequence valve, which delays the movement of air to the accessory in order to prioritize the pressurizing of the s for the braking system. Once the pressure in the system reaches 448 kpa (65 psi), the sequence valve opens and allows the accessory to be filled. An anti-return valve, also installed at the entrance to the accessory, prevents the depressurization of the in case of a major leak in the supply system. A safety valve expels any overproduction of compressed air in case of a breakdown of the air flow control within the system. This valve expels the compressed air once the pressure is above that required for normal operation of the system. If the pressure falls below this value, the safety valve closes, in order for the system to continue to be fed with compressed air. Finally, a tow connector is installed to supply the brakes and other pneumatic accessories during a towing operation.

20 2011JA14 20 / air dryer supply primary coils secondary ping tank Compressor external governor emergency accessory check valve air supply connector COMPRESSED AIR (PRESSURE): 110 to 135 psi (758 to 931 kpa) automatic purge valve manual purge valve safety valve sequence valve Air is: a. compressed by the compressor, whenever it receives a signal from the governor b. cooled as it passes through the copper coils c. filtered and dried by the air dryer d. accumulated in the supply, feeding in turn the primary, the secondary, the emergency, and the accessory. Figure 1E - Schematic Diagram of the Pneumatic Supply System with SKF Dryer