MSW020/025-E [A895]; MPB040-E [B827]; MPW045-E [B802 ...

1 MaintenanceBRAKESMSW020/025-E [A895]; MPB040-E [B827]; MPW045-E [B802]; mpw050 -E [C802]PART NO. 5241548931800 YRM 1005 SAFETY PRECAUTIONSMAINTENANCE AND REPAIR When lifting parts or assemblies, make sure all slings, chains, or cables are correctly fas-tened, and that the load being lifted is balanced. Make sure the crane, cables, and chainshave the capacity to support the weight of the load. Do not lift heavy parts by hand, use a lifting mechanism. Wear safety glasses. DISCONNECT THE BATTERY CONNECTOR before doing any maintenance or repair onelectric lift trucks. Disconnect the battery ground cable on internal combustion lift trucks. Always use correct blocks to prevent the unit from rolling or falling. See HOW TO PUT THELIFT TRUCK ON BLOCKS in theOperating Manualor thePeriodic Maintenancesection. Keep the unit clean and the working area clean and orderly. Use the correct tools for the job.

2 Keep the tools clean and in good condition. Always useYA L E A P P R OV E Dparts when making repairs. Replacement parts must meetor exceed the specifications of the original equipment manufacturer. Make sure all nuts, bolts, snap rings, and other fastening devices are removed before usingforcetoremoveparts. Always fasten a DO NOT OPERATE tag to the controls of the unit when making repairs, orif the unit needs repairs. Be sure to follow theWARNINGandCAUTION notes in the instructions. Gasoline, Liquid Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Diesel fuel areflammable. Be sure to follow the necessary safety precautions when handling these fuelsand when working on these fuel systems. Batteries generate flammable gas when they are being charged. Keep fire and sparks awayfrom the area. Make sure the area is well :The following symbols and words indicate safety information in this manual:WARNINGI ndicates a condition that can cause immediate death or injury!

3 CAUTIONI ndicates a condition that can cause property damage!BrakesTable of ContentsTA B L E O F C O N T E N T ..1 Special Assembly Repair ..3 Brake Override ..3 Remove ..8 This section is for the following models: MSW020/025-E [A895]; MPB040-E [B827]; MPW045-E [B802]; mpw050 -E [C802] 2005 Yale Materials Handling YRM 1005 DescriptionGeneralWARNINGDo not operate a lift truck that needs repairs. If arepair is necessary, put a DO NOT OPERATE tag onthe control handle. Remove the key from the performing repairs or adjustments on thebrake system, blocks must be placed under eachsideoftheframetoraisethedrivetireoff theground. The blocks must prevent the lift truck fromfalling and causing personal injury or propertydamage. See Periodic Maintenance 8000 YRM 1009or Periodic Maintenance 8000 YRM 1048, How toPut a Lift Truck on disconnect and separate the battery con-nector so that the connector is completely free be-fore performing any service or repairs.

4 If the con-nector is not completely free, it can reconnect. Tagthe connector: DO NOT section has the description and repair proceduresfor the electric brake on the MSW020-E, MSW025-E, MPB040-E , MPW045-E , and mpw050 -E lift assemblies may vary in appearance. Althoughsome assemblies mayAPPEARto be adjustable,brake assemblies used on these trucksARE NOTADJUSTABLE. Friction between parts inside the brakewill produce brake dust, squeaking, and extreme heatunder normal operating assem-blies can generate surface temperatures up to 130C(266F) and odors during heavy operation. Functionsof the brake assembly depend on a dry and cleanenvironment. Small amounts of oil or grease on thefriction surfaces of the brake can seriously compromisethe brakes ability to (Neutral) of the spring-applied/electrically re-leased friction brakeNOTE:The preferred method of stopping the truck is:Regenerative (Neutral) brakingorControlled pluggingRegenerative (Neutral) braking applies a retarding forceto the drive wheel through the traction motor, allowingthe unit to slow to a gradual stop.

5 It is applied by re-turning the speed/direction control to theOFFpositionor by placing the hand brake lever(s) in the first plugging is reversing the speed/directioncontrol while traveling, causing the unit to slow to astop. Return the speed/direction control to theOFFpo-sition to remain stopped. If the speed/direction controlis not returned to theOFFposition, the lift truck will ac-celerate in the opposite direction. Controlled pluggingshould stop the truck within a few feet, depending onspeed and parking brake is a spring-applied, electrically re-leased friction brake mounted to the drive motor. Whenthe parking brake is applied, springs inside the brakeassembly compress a rotating friction disk against twostationary release the the the key switch to the control handle arm to the operating orBRAKE OFFposition. Refer to Figure direction/speed control (butterfly knobs) inthe direction of Precautions1800 YRM 1005 Figure 1.

6 Brake OperationThe parking brake is applied when the control han-dlearmismovedtotheBRAKE ONposition (fullup or full down position) or if a traction fault lift truck must meet the applicableHOLD ONGRADE requirements; the parking brake should becapable of holding the lift truck on a 10 percentgrade with the maximum rated PrecautionsWARNINGB lock each side of the truck under the drive unitframe. Position blocks on both sides of the loadwheels. The blocks must prevent the lift truck fromfalling and causing personal injury or capacitor in the transistor controller can holdan electrical charge after the battery is discon-nected. To prevent electrical shock and personalinjury, discharge the capacitor before inspectingor repairing any component. Wear safety certain the battery has been the capacitors in the controller by con-necting a 200-ohm, 2-watt resistor across thecontroller s B+ and Bterminals with insulatedjumper wires.

7 Do NOT use a screwdriver to dis-charge the traction motor controller. See Figure 2or Figure avoid personal injury and prevent electricalshock, perform the following steps before per-forming any troubleshooting or adjustments, andbefore connecting or disconnecting a handset avoid controller damage, always disconnectthe battery. Discharge the capacitor and never putpower to the controller with any power wire dis-connected. Never short any controller terminal ormotor terminal to battery. Make sure to use properprocedure when servicing the the lift truck so that the drive wheel is off thefloor. Refer to the proper section for your truck:Pe-riodic Maintenance8000 YRM 1009 orPeriodicMaintenance8000 YRM 1048, How to Put a LiftTr u c k o n B l o c k s . the key switch to theOFFposition and discon-nect the the capacitors in the controllers by con-necting a 200-ohm, 2-watt resistor across the con-troller s B+ and Bterminals.

8 See Figure 2 or Fig-ure 3 for your truck. DO NOT short across the mo-tor controller terminals with a screwdriver or jumperwire. Remove the 200-ohm, 2-watt resistor beforereconnecting the YRM 1005 Brake Assembly Repair1. POSITIVE CONNECTION2. NEGATIVECONNECTION3. INSULATED JUMPER WIRES4. 200-OHM, 2-WATT RESISTORF igure 2. Discharging Controller mpb040 -E1. NEGATIVE CONNECTION2. POSITIVECONNECTION3. 200-OHM, 2-WATT RESISTOR4. INSULATED JUMPER WIRESF igure 3. Discharging Controller MSW020/025-Eand MPW045/050-EBrake Assembly RepairBRAKE OVERRIDECAUTIONN ever operate the lift truck while the brake overridefeature is being brake can be disengaged when a truck cannot beoperated but needs to be moved. On the main wiringharness approximately 300 mm (12 in.) above theMDU, the brake wiring harness is connected. An extrafour pin connector for the brake override feature issecured near this connection with wire ties.

9 Disconnectthe connectors and connect the brake wiring harnessto the brake override connector. This will energizethe brake coil which will release the brake. The drivemotor will not activate while the jumper is the lift truck to a safe location and disconnectthe brake override connector. The brake will applywhen the brake override connector is disconnected orwhen power to the brake override circuit is the brake wiring harness to the main wiringharness and proceed with repairs. If the battery doesnot have sufficient charge, or if certain components ofthe lift truck are damaged, the brake may not releasewith the brake override circuit engaged. In this case,the malfunction must be corrected before the brake canbe released. See Figure Assembly Repair1800 YRM 10051. BRAKE WIRING HARNESS2. MAIN WIRING HARNESS3. BRAKE OVERRIDE CONNECTORF igure 4.

10 Brake Override ConnectorREMOVEMove the truck to a safe location before beginning workand block the wheels to prevent movement. Removethe key from the switch and disconnect the battery :For the following instructions, refer to Figure r n k e y s w i t c h t oOFFposition and disconnect bat-tery. Block the drive tire to prevent drive unit compartment covers and capacitor in the transistor controller can holdan electrical charge after the battery is discon-nected. Discharge the capacitor before inspectingor repairing any component in the MDU compart-ment to prevent personal injury and damage to theelectrical system. Always wear safety capacitors. Refer to Special Precautionsin the front of this Allen-head screws (7) and washers (8)from the cover that secure motor and brake assem-bly to drive motor with one hand and remove re-maining Allen-head screw (2) and washer (3) withother motor and brake assembly from and remove wires and cables from motor andunplug brake wire motor on workbench securely supported inan upright O-ring from nut (9) from motor gear (11) and woodruff key (16) from drivemotor a standard puller, remove the bearing (13)andoilslinger(12) assemblies may vary in appearance.