08-30-01 Doc. 20004, Rev 4 Dethmers Manufacturing Company DOING OUR BEST TO PROVIDE YOU THE BEST MODEL 91 BRAKE ACTUATORS OWNERS/OPERATORS MANUAL READ complete manual CAREFULLY BEFORE attempting operation.
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DEMCO MODEL DA91 ACTUATOR Model DA91 is a heavy duty surge brake actuator for trailers with two or four wheels. When brakes are applied on the towing vehicle, forward inertia of trailer toward towing vehicle applies brakes on trailer in direct relation to manner brakes are applied on towing vehicle. Brake towing vehicle hard and brakes on trailer are applied hard. Master cylinder push rod spring assembly protects system from hydraulic pressure overload.
SAFETY TAKE NOTE! THIS SAFETY ALERT SYMBOL FOUND THROUGHOUT THIS MANUAL IS USED TO CALL YOUR ATTENTION TO INSTRUCTIONS INVOLVING YOUR PERSONAL SAFETY AND SAFETY OF OTHERS. FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN INJURY OR DEATH. THIS SYMBOL MEANS ATTENTION BECOME ALERT YOUR SAFETY IS INVOLVED! SIGNAL WORDS Note use following signal words DANGER, WARNING, and CAUTION with safety messages.
SAFETY...YOU CAN LIVE WITH IT EQUIPMENT SAFETY GUIDELINES Every year many accidents occur which could have been avoided by a few seconds of thought and a more careful approach to handling equipment. You the operator, can avoid many accidents by observing and following precautions in this section. To avoid personal injury, study the following precautions and insist those working with you, or you yourself, follow them.
SAFETY SIGN LOCATIONS Types of safety sign and locations on equipment are shown in illustration below. Good safety requires that you familiarize yourself with various safety signs, type of warning, and area or particular function related to that area, that requires your SAFETY AWARENESS. A. A. BH21003 Qty.
SAFETY SIGN CARE • Keep safety signs clean and legible at all times. • Replace safety signs that are missing or have become illegible. • Replacement parts that displayed a safety sign should also display safety sign. • Safety signs are available from your distributor, dealer parts department, or factory. How to install safety signs: • Be sure that installation area is clean and dry. • Decide on exact position before you remove backing paper. • Remove smallest portion of split backing paper.
BEFORE OPERATION: • Carefully study and understand this manual. • Always wear protective clothing and substantial shoes. • Give equipment a visual inspection for any loose bolts, worn parts, or cracked welds, and make necessary repairs. Follow maintenance safety instructions included in this manual. • Be sure there are no tools lying on or in equipment. • Do not use equipment until you are sure that area is clear, especially around children and animals.
• Beware of bystanders, PARTICULARLY CHILDREN! Always look around to make sure it is safe to start engine of towing vehicle or move equipment. This is particularly important with higher noise levels, as you may not hear people shouting. • NO PASSENGERS ALLOWED- Do not carry passengers anywhere on or in equipment. • Do not clean, lubricate, or adjust your equipment while it is moving. • When halting operation, even periodically, set towing vehicles parking brake, shut off engine, and remove the ignition key.
FOLLOWING OPERATION • Following operation, or when unhitching, stop towing vehicle, set brakes, shut off the engine and remove ignition key. • Store unit in an area away from human activity. • Do not permit children to play on or around stored unit. • Make sure all parked units are on a hard, level surface and engage all safety devices. • Wheel chocks may be needed to prevent unit from rolling.
• Watch for obstructions overhead and side to side while transporting. • Always operate equipment in a position to provide maximum visibility at all times. Make allowances for increased length and weight of equipment when making turns and/or stopping. PERFORMING MAINTENANCE • Good maintenance is your responsibility. Poor maintenance is an invitation to trouble. • Make sure there is plenty of ventilation. Never operate engine of towing vehicle in a closed building. Exhaust fumes may cause asphyxiation.
BOLT TORQUE TORQUE DATA FOR STANDARD NUTS, BOLTS, AND CAPSCREWS. Tighten all bolts to torques specified in chart unless otherwise noted. Check tightness of bolts periodically, using bolt chart as guide. Replace hardware with same grade bolt. NOTE: Unless otherwise specified, high-strength Grade 5 hex bolts are used throughout assembly of equipment. Bolt Torque for Standard bolts * Torque Specifications “A” GRADE 2 lb-ft (N.m) GRADE 5 lb-ft (N.m) GRADE 8 lb-ft (N.
WARNING • DEMCO MODEL DA91 BRAKE ACTUATOR To Prevent Serious Injury Or Death: Review all of the following instructions before installation and use of hydraulic brake actuator. • Dealers or Distributors must review these instructions with ultimate user. • Failure to follow these instructions, or failure to properly maintain braking system after installation, can result in loss of braking action which could cause severe property damage, personal injury or death.
5. Once bleeding is completed, refill master cylinder and attach cap (#24) securely. Replace emergency lever spring, lever guide, lock washers and 5/16" hex head bolts. 6. Test brakes by pulling emergency lever (#23) forward until it locks into its second notch position. (Lever should be approximately straight up.) Attempt to rotate wheels in a forward direction. If any wheels rotate, brakes must be adjusted.
DEMCO BRAKE PRODUCTS - LIMITED WARRANTY 1. Extent and Duration of this Warranty: Your Demco brake product is warranted to be free from defects in materials and workmanship under normal use and service for a period of one year after date of purchase by original owner when properly installed, used and maintained by purchaser.
DEMCO BRAKE PRODUCTS - LIMITED WARRANTY CONTINUED 1) 2) 3) 4) 5) 6) This warranty does not cover: normal wear and tear. road film or gravel damage to paint. paint. rust damage. any Demco brake product that has been loaded in excess of load capacity stated on identification label. Accessory parts, materials or components. Warrantor has a policy of continuous product improvement.
ACTUATOR PARTS BREAKDOWN not included **18 20 12 24 21 30 5398 Cast Master Cylinder Repair Kit 33 17 11 14 **19 16 5680 Plastic Master Cylinder Repair Kit (gasket 09153 included) 9 Model DA91 Outer Case 13 5221 Coupler Repair Kit 15 8 27 15 8 8 7 2" Fulton Ball Coupler RATED AT 6000# 29 28 32 10 31 6 7 4 26 2 5 Model DA9150 Outer Case 1 3 (OPTIONAL) FREE BACKING SOLENOID KIT (5404) PARTS BREAKDOWN Model 91 ACTUATOR PARTS LIST PART NO.
AVAILABLE HITCH CONFIGURATIONS 35 34 39 32 32 33 Clevis Channel Up RATED AT 7500# 33 36 Model 91 Drop Slider Tube Channel Down with Pintle RATED AT 7500# 34 41 42 34 49 43 37 46 49 46 2-5/16" Bulldog Ball Coupler welded to clevis channel RATED AT 7500# 2" Bulldog Ball Coupler welded to drop slider tube RATED AT 7000# 2-5/16" Bulldog Ball Coupler welded to drop slider tube RATED AT 7500# 46 34 49 47 Channel Down with Clevis RATED AT 7500# 38 46 2-5/16"Lever Lock Bolt On Coupler RATED
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DETHMERS MFG. COMPANY P.O. BOX 189 4010 320th St., BOYDEN, IA. 51234 PH: (712) 725-2311 or (712) 725-2302 FAX: (712) 725-2380 TOLL FREE: 1-800-54DEMCO (1-800-543-3626) www.demco-products.
