AGCO ALLIS 1920H Service Manual

Overview and purpose

The AGCO ALLIS 1920H service manual provides a detailed, technician-focused guide to the maintenance, inspection, and repair of the 1920H model. This document is intended to support certified technicians and trained operators in diagnosing issues, planning preventive maintenance, and performing corrective repairs with accuracy and safety in mind. It consolidates practical procedures, typical fault conditions, and recommended service intervals to help keep the machine performing to its design specifications. The content emphasizes real-world applicability, including step-by-step procedures, torque specifications, lubrication points, and alignment checks to ensure optimal performance. By following the guidance, technicians can minimize downtime and extend the service life of the equipment while preserving operator safety and equipment reliability.

The manual's purpose is to serve as a reliable reference that translates manufacturer engineering data into actionable maintenance tasks. It supports troubleshooting efforts by outlining common failure modes, expected symptoms, and diagnostic steps. The information is organized to facilitate quick access during field service, with clear instructions that can be followed in workshop or at a job site. The overall goal is to enable technicians to restore full functionality, maintain efficiency, and uphold safety standards during every intervention. The manual also reinforces adherence to proper PPE, environmental considerations, and safe handling practices throughout all procedures.

The AGCO ALLIS 1920H is a compact utility tractor designed for a range of agricultural and landscap ing tasks. This model combines a robust chassis with a responsive operator platform to provide reliable performance in daily fieldwork and maintenance operations. Identifying the exact configuration is important for selecting the correct service procedures, parts, and lubrication intervals. Understanding the model's lineage and assembly details helps technicians verify compatibility with attachments, hydraulic kits, and electrical harnesses. The 1920H series typically features a diesel powertrain, standard diesel oxidation system, and a sealed electrical system designed for outdoor use. Proper identification sets the foundation for accurate maintenance records and scheduled service plans.

Key components and layout of the AGCO ALLIS 1920H emphasize accessibility and serviceability. The engine bay is arranged to allow straightforward access to filters, belts, and cooling components, minimizing downtime during routine maintenance. The operator platform is oriented for clear visibility of gauges and controls, enabling efficient diagnostic checks while in the field. The hydraulic system is designed with modular sections to simplify isolation of circuits for pressure testing and component replacement. Electrical modules are grouped to reduce wiring complexity and facilitate troubleshooting with standard handheld scanners and diagnostic tools. A well-organized layout supports safe lifting, component removal, and reinstallation during repair tasks.

Specifications and serial data for the AGCO ALLIS 1920H cover critical attributes such as engine displacement, horsepower rating, and hydraulic flow, which influence maintenance intervals and part compatibility. Pay close attention to serial numbers when ordering service kits to ensure the correct version of components and software calibration is used. The data plate typically lists nominal power output, operating weight, wheelbase, and tire size, all of which affect loading limits and stability during use. Recommended lubrication points, oil capacities, and filter part numbers are tied to the identified serial range, underscoring the need for precise documentation during service. Adhering to the specified torque values and assembly sequences protects fasteners and seals, reducing the likelihood of leaks and premature wear. Regular verification of specifications against the original build sheet helps maintain tractor reliability and longevity.

Preparation and maintenance planning is the foundation of reliable operation for the AGCO ALLIS 1920H. A well-structured plan minimizes unscheduled downtime and extends the service life of critical components. Start with a clear understanding of the machine’s daily usage, operating environment, and duty cycles, then translate these factors into a practical maintenance calendar. Establish responsibilities and maintain a log that records completed tasks, observed anomalies, and parts replacements. This proactive approach helps identify trends and allows for timely interventions before failures occur, ultimately safeguarding operator safety and productivity.

Pre maintenance checklist involves verifying the machine’s overall condition before any work begins. Inspect the chassis and frame for signs of wear, cracks, or deformation that could indicate stress or impact damage. Ensure electrical systems are accessible and free of corrosion, with battery terminals tight and clean. Check fluid levels, including engine oil, hydraulic fluid, coolant, and fuel, noting any discrepancies that may signal leaks or contamination. Confirm that all safety devices, guards, and warning labels are intact and legible, and review the operator’s manuals for any model-specific cautions. Documenting the initial condition provides a baseline for subsequent maintenance and helps guide repair decisions.

Lubrication and fluid intervals are critical to maintaining optimal performance and preventing excessive wear. Adhere to the manufacturer’s recommended intervals for engine oil changes, filter replacements, and hydraulic fluid top-offs, while accounting for operating temperature and load. Use the specified lubricant grades to ensure proper viscosity and additive compatibility with seals and gaskets. Regularly inspect lubrication points, such as pivot joints, drive shafts, and attachment interfaces, applying grease or oil as dictated by service intervals. Monitor coolant and hydraulic systems for signs of contamination or foaming, and replace filters at prescribed intervals to maintain clean fluids and prevent cavitation or reduced cooling efficiency.

Tire and track maintenance require attention to inflation pressures, tread condition, and alignment to maximize traction and minimize wear. For wheeled configurations, verify that all tires are inflated to the recommended pressures with consideration given to load distribution and operating conditions. Inspect tread depth and look for cuts, punctures, or sidewall damage, rotating or replacing tires as needed to maintain even wear. For track-equipped configurations, examine track tension, alignment, and carrier rollers for wear or looseness, adjusting as specified by the service procedures. Regularly clean debris from undercarriage components to prevent material buildup that could alter balance or heat dissipation. A consistent approach to tire and track maintenance supports stable handling and reduces the likelihood of downtime due to tire failure or misalignment.

The AGCO Allis 1920H engine system combines robust mechanical design with modern fuel, air, and electrical subsystems to deliver reliable performance in agricultural tasks. Understanding the engine’s core components—such as the fuel injection system, air intake and filtration, and exhaust flow—helps technicians diagnose issues quickly and perform accurate maintenance. Regular inspection of fuel lines, connectors, and filters is essential to prevent power loss, excessive smoke, and hard starting. The engine’s operation relies on precise timing, proper lubrication, and clean air and fuel delivery to maintain optimal combustion efficiency under varying load conditions. By familiarizing yourself with normal operating parameters, you can identify deviations that indicate wear, leaks, or component failure early in the service cycle.

Fuel system maintenance focuses on ensuring clean fuel delivery and consistent combustion. Start with inspecting the primary and secondary fuel filters for contamination and replace them according to the manufacturer’s schedule or whenever fuel appears discolored or viscous. Check fuel lines for cracks, leaks, or signs of swelling, and verify that clamps are secure to avoid air ingress. The fuel pump should exhibit stable delivery pressure; if pressure fluctuates or the engine exhibits hard starting, perform a pressure test and inspect for air leaks or a malfunctioning lift pump. When working with ethanol-blended fuels, consider fuel stabilizers and corrosion inhibitors to protect injectors and seals from long-term degradation. Maintaining a clean, dry fuel system minimizes carbon buildup and helps sustain predictable engine response during PTO use, harvesting, and other demanding tasks.

Air and exhaust systems play a critical role in engine efficiency and emission control. Regularly inspect the air intake for obstructions, ensuring the air filter housing is sealed and the filter media remains free of oil saturation or collapse. Replace clogged filters promptly to avoid reduced airflow, which can cause overheating and power loss. Examine the turbocharger (if equipped) and intercooler for signs of oil leaks, excessive play, or foreign object damage, and listen for unusual whines or surges that indicate bearing wear. The exhaust system should be free of leaks, with intact gaskets and intact muffler components to maintain proper backpressure and reduce nuisance noise. A clean air and exhaust path supports colder intake temperatures and more efficient combustion, resulting in improved fuel economy and engine longevity during field operations.

Electrical system diagnosis requires methodical testing of starting, charging, and control circuits. Begin with battery condition, ensuring terminals are clean, posts are tight, and the acid specific gravity matches the expected range for your climate. Inspect wiring harnesses for insulation damage, loose connections, and signs of vibration wear near engine mounts and the alternator. Use a multimeter to verify charging voltage at the battery and compare it to the manufacturer’s specification under various engine speeds. If sensors or actuators fail to respond, test them in circuit with the appropriate load and consult the service data for expected resistance or voltage values. In systems with electronic engine control modules, check for stored fault codes and clear nonessential faults after repairs, followed by a functional test to confirm proper restart and idle stability. Maintaining a dependable electrical system reduces the risk of no-start conditions and ensures reliable operation during long work shifts.

Hydraulic and power transmission systems

The hydraulic system in the AGCO Allis 1920H combines multiple subsystems to provide precise control and reliable power for implements and drive functions. Its design integrates hydraulic pumps, reservoirs, valves, and actuators in a configuration that supports both steering assist and implement operation. Proper understanding of flow paths, pressure ratings, and fault indicators is essential for safe and effective maintenance. Regular inspection of hoses, fittings, and seals helps prevent leaks that can degrade performance and lead to component wear. When diagnosing system behavior, correlate observed pressures, temperatures, and noises with manufacturer specifications to identify the likely source of issues.

Hydraulic performance directly influences machine stability and operator control. Maintain clean fluid conditions and monitor fluid levels to ensure consistent responsiveness under varying load conditions. The hydraulic circuit is designed to respond quickly to operator inputs, so gradual degradation in flow or relief pressure can manifest as sluggish gearing or delayed implement action. Ensure that the hydraulic power pack and reservoir are properly mounted and that cooling provisions are unobstructed to prevent overheating during extended operation. Regularly verify that control levers and joystick valves return to neutral positions smoothly to avoid unintended movements.

Hydraulic fluid and filtration

Selecting the correct hydraulic fluid is critical for compatibility with seals, hoses, and metal components within the system. Use the viscosity grade recommended by the manufacturer and avoid mixing fluids from different formulations, as this can alter lubricity and viscosity characteristics. The filtration system must be inspected and replaced according to the service schedule to remove particulates that can abrade internal components or clog orifices. When replacing filters, document the part numbers and the replacement interval to maintain traceability and ensure that the filtration efficiency remains within specification. Monitor fluid contamination levels through regular sampling, looking for metallic debris, cloudiness, or unusual color changes that indicate wear or ingress of contaminants.

Additionally, maintain proper filtration by avoiding over-tightening filter housings and ensuring O-rings remain intact and properly seated. Leaks at connection points should be repaired promptly, using compatible sealants or gaskets as specified, to prevent air entrainment and loss of system pressure. Record fluid temperatures during operation to confirm that the system remains within the approved operating range, as excessive heat can degrade viscosity and reduce lubrication. Periodic conductivity and particulate testing can help detect early signs of system deterioration before major failures occur.

Power takeoff and transmission maintenance

The power takeoff (PTO) and transmission are central to tractor versatility, delivering controlled power to auxiliary implements while maintaining overall drive performance. Inspect PTO shafts for wear, alignment, and secure engagement of protective guards to prevent injury and mechanical damage. Lubrication is essential for gear interfaces and bearings; follow the manufacturer’s schedule for oil changes and grease points, ensuring that lubricant type and grade match the specification stamped on the component. Transmission maintenance requires monitoring gear oil levels and temperature, especially during heavy-duty operation, to prevent gear scoring and hydraulic clogs that can compromise drive efficiency. When performing maintenance, verify that detents, shifts, and linkages move without excessive play and that hydraulic or mechanical interlocks engage as designed.

During routine service, inspect the hydraulic pump drives and PTO clutches for uneven wear, glazing, or slipping. Replace worn components with OEM parts to preserve alignment, vibration characteristics, and overall system balance. After any major service, perform a functional test under load to confirm that hydraulic functions and transmission actions respond predictably and safely. Keep comprehensive maintenance records, including replaceable component lifespans, service dates, and observed anomalies to aid future diagnostics and prevent recurring faults.

Fuel and emissions control

The fuel system of the AGCO ALLIS 1920H is designed to deliver clean, consistent fuel flow under a variety of operating conditions. Key components include the fuel tank, supply and return lines, filters, injectors, fuel pump, and the associated sensors that monitor pressure and temperature. Proper maintenance begins with keeping the fuel system free of contaminants, which can cause injector clogging, reduced fuel efficiency, and rough engine operation. Regular inspection for leaks, cracked lines, and secure connections ensures that the system maintains optimal pressure and flow. When working on the fuel system, always use the manufacturer-recommended fuel grade and avoid adding anything that could degrade seals or filter media. By adhering to these guidelines, you reduce the likelihood of moisture ingress and fuel contamination that can compromise engine performance and emissions compliance.

Emissions control on the 1920H relies on a combination of air management, fuel metering, and exhaust treatment to minimize environmental impact while preserving performance. Modern engines use precise electronic control to regulate the air-fuel ratio, and secondary measures such as particulate filters or catalytic converters may be integrated depending on the model year and regional requirements. Routine maintenance includes ensuring the intake system is free of obstructions, the EGR system (if equipped) operates without sticking valves, and that sensors such as oxygen, temperature, and pressure sensors are calibrated and functional. A clean, well-maintained exhaust path reduces backpressure and helps the emission control system work more efficiently. Do not bypass any emissions components, as this can lead to excessive pollutants, poor engine performance, and potential warranty or legal issues.

Diagnostics and troubleshooting for fuel and emissions require a methodical approach to identify root causes without encouraging unnecessary disassembly. Start with a visual inspection of hoses, clamps, and connections for signs of wear, cracking, or leakage, and check that all mounting hardware is secure. Use approved diagnostic tools to read sensor data and fault codes, verifying that readings fall within the specified ranges for the engine’s operating conditions. When a fault code indicates a fuel or emissions issue, correlate the code with symptoms such as hard starting, misfires, hesitation, or increased smoke. Progressive steps typically involve verifying fuel pressure, inspecting injectors and filters, and confirming that the intake and exhaust pathways are clear. After any repair, perform a functional test under load to ensure that performance, fuel efficiency, and emissions outputs meet the manufacturer’s standards.

For routine service, replace primary and secondary fuel filters at the intervals recommended in the service schedule, and ensure the fuel system is purged of air after maintenance procedures. Inspect the vacuum and pressure lines for signs of deterioration and replace them if needed to prevent unintended air ingress that can destabilize combustion. Emissions-related components should be checked for corrosion, loose electrical connections, and proper thermal management. It is important to maintain accurate service records, noting the dates and hours when filters, sensors, or exhaust components were serviced or replaced. Keeping meticulous records helps in diagnosing recurrent issues and ensures continued compliance with applicable standards over the life of the machine.

Cooling system and environmental considerations

The cooling system of the AGCO Allis 1920H is designed to maintain optimum engine temperatures under a variety of operating conditions. Proper operation relies on a complete understanding of the layout, the correct coolant specification, and diligent level monitoring. A well-maintained cooling system protects the engine from overheating, reduces wear on components, and contributes to overall machine reliability in demanding agricultural environments. Environmental considerations include proper coolant disposal, leak prevention, and managing ambient temperature effects on radiator performance.

Cooling system layout involves recognizing the major components: the radiator, water pump, thermostat, expansion tank, intercooler if equipped, and associated hoses and clamps. The system forms a closed loop that circulates coolant through the engine block to absorb heat and then disperses it via the radiator. A properly routed and supported network of hoses minimizes the risk of collapse, kinks, or vibration-induced wear. Regular visual inspections should verify that fan blades spin freely, the belt tension is correct, and there are no obstructions around the radiator fins that could impede airflow. Understanding the path of coolant flow helps technicians diagnose temperature anomalies more quickly during service.

Coolant specification and level checks require adherence to manufacturer recommendations regarding mix ratios, approved coolant types, and concentration ranges. Use only the coolant type specified in the service data, as deviations can lead to corrosion, scale formation, and reduced heat transfer efficiency. When checking coolant levels, ensure the engine is cool to prevent scalding and to obtain an accurate reading. The expansion tank should be within the marked level range; if the level is low, inspect for leaks in hoses, clamps, the radiator, and the water pump. After refilling, run the engine to operating temperature and recheck the level once the system has stabilized, topping up as necessary. Regular coolant replacement intervals should be observed to preserve anti-corrosion properties and prevent sediment buildup that can compromise cooling performance.

Thermal management and troubleshooting cover common signs of cooling system distress and step-by-step methods to identify the root cause. Indicators such as rising coolant temperature, loss of coolant without visible leaks, visible steam, or irregular temperature readings during operation warrant a systematic inspection. Start with the radiator—check for blockages, damaged fins, and ensure the cap seals correctly. Next, verify the water pump operation, including impeller integrity and belt condition; a slipping belt or faulty pump will impair coolant flow and raise operating temperatures. Inspect the thermostat for proper opening and ensuring it regulates temperature as designed. If overheating persists, test for external leaks, pressure-test the system, and verify the cooling fan operation under load. Addressing exhaust or head gasket concerns requires following the diagnostic path to confirm or rule out internal engine issues, then implementing the appropriate repair or replacement procedures.

Environmental considerations extend to coolant handling and disposal, prevention of soil and water contamination from leaks, and the use of outdoor-rated components when appropriate. Spills should be contained immediately using absorbent materials, and contaminated fluids must be disposed of at authorized facilities according to local regulations. Regular maintenance routines should include checking for signs of external leaks around hoses, clamps, and the radiator core, especially after periods of heavy use or exposure to harsh field conditions. When operating in extreme temperatures, observe manufacturer guidance for coolant concentration and cap pressure to maintain system integrity. Finally, document all service actions, including coolant specification, level readings, and any parts replacements, so future maintenance can be performed with complete traceability and confidence.

Electrical and wiring diagrams

The electrical system of the AGCO ALLIS 1920H is designed to support reliable starting, operation, and safety interlocks across the machine’s critical subsystems. At the core lies the main power distribution network, which divides power from the battery through the ignition switch, fuses, and circuit breakers to essential circuits such as the engine management, charging system, lighting, and accessory loads. Knowledge of the grounding scheme is essential for diagnosing voltage drops and ensuring proper sensor and actuator performance. A thorough check of battery condition, cable integrity, and clean, tight connections should be routine before proceeding with any diagnostic procedure. The diagram set provides a schematic overview that helps technicians trace circuits from the battery to individual components, enabling efficient fault isolation and repair.

Wiring integrity is critical for both performance and safety. The harnesses are routed to minimize vibration and exposure to heat, with protective sleeving and secure fasteners to prevent abrasion and chafing. When inspecting harnesses, pay close attention to areas near moving parts, radiator shrouds, and where harnesses pass through bulkhead conduits. Corrosion-resistant connectors and weatherproof seals are used in exterior locations, while interior harnesses incorporate high-temperature insulation for engine bay components. The diagrams show connector pinouts, wire gauges, and color codes, which facilitate accurate continuity checks and resistance measurements. Any discovered damage should be repaired with OEM-compatible splices, or complete harness replacement if multiple circuits are compromised.

Safety interlocks and sensors form a critical layer of protection for both operator and equipment. The ignition interlock, seat switch, and safety shutoff circuits are designed to prevent engine cranking or operation when conditions are unsafe. Speed and position sensors provide feedback to the engine control module and transmission control, ensuring that engine load and gear engagement conditions remain within designed parameters. The diagrams detail the exact wiring paths for these interlocks and sensors, including connector positions, pin numbers, and typical resistance ranges. When diagnosing, verify that each interlock input reads correctly in the appropriate state and that any fault flags in the control modules are cleared only after confirming the physical condition of the switches and wiring. Calibration procedures may be required for sensors after component replacement to restore accurate readings and safe operation.

The AGCO Allis 1920H service environment relies on precise interpretation of diagnostic signals to guide maintenance and repair. Error codes are typically displayed through the tractor’s dashboard interface or a diagnostic terminal connected to the machine’s electronic control module. Begin by logging the fault codes in a structured manner, noting any accompanying status indicators such as engine RPM, oil pressure, or temperature readings. It is essential to consult the equipment’s wiring diagrams and service manuals for exact code definitions, as similar codes can have different meanings depending on model year and ECU software revision. After recording the codes, use the manufacturer’s recommended decoding table to determine whether the fault is electrical, hydraulic, sensor-related, or mechanical in nature. This initial step prevents misdiagnosis and ensures that subsequent troubleshooting actions are targeted and efficient.

General service procedures for the AGCO Allis 1920H involve establishing a safe and clean work environment, disconnecting power sources, and verifying the status of critical safety devices before any disassembly. Begin by turning off the engine, removing the key, and engaging wheel chocks or stabilizers as required. For electrical work, disconnect the battery negative terminal to prevent accidental short circuits or arcing. Use appropriate personal protective equipment and follow lockout/tagout procedures where applicable. Document every service action, including torque values, lubricant types, and replacement part numbers, to maintain a thorough service history that supports future diagnostics and warranty compliance. Regular calibration checks of sensors and control modules help maintain accurate readouts and reliable operation over time.

Component removal and reinstallation for the AGCO Allis 1920H requires careful planning to avoid damage to adjacent systems and to simplify reassembly. Start with a hot or cold engine assessment to determine whether components must be cooled prior to removal, particularly for heavy equipment like hydraulic pumps or alternators. When removing components, label all connectors, hoses, and fasteners, and photograph complex assemblies to aid accurate reinstallation. Use the manufacturer’s specified torque sequence and fastener torque values during reassembly to ensure proper mating and to prevent warping or misalignment. After reinstalling any major component, perform a functional test and verify that all interlocks, sensors, and safety features initialize correctly. Finally, recheck fluid levels, perform a leak test, and clear any diagnostic codes once the system has stabilized, ensuring the unit returns to baseline operating conditions and diagnostic readiness for subsequent use.

The AGCO ALLIS 1920H employs a three-point hitch system to attach a wide range of implements, enabling versatile field work and transport tasks. Understanding the hitch geometry, link lengths, and top link adjustments is essential for safe and efficient operation. Start by inspecting the lower lift arms, top link, and stabilizers for wear, bending, or looseness, ensuring pin and bushing integrity before attachment changes. When mounting implements, align the three-point hitch points with the corresponding implement clevises, verify that all locking pins are properly seated, and confirm that hydraulic arms respond smoothly to control inputs without binding. Regular lubrication of pivot points and joints reduces resistance and prolongs service life, while keeping ballast within recommended limits helps maintain stable implement depth and traction. Document any deviations from standard alignment or operation to ensure they are addressed before proceeding with field work.

Implement hydraulic controls are vital for precise lift, angle, and tilt operations. The hydraulic system must be checked for proper pressure, response time, and absence of leaks at hoses and connections. Verify that the control lever movements translate to expected implement motion, and that circuits respond without excessive lag. Inspect hoses for wear, cracks, or bulges, and replace any compromised lines immediately to prevent hydraulic failure. When installing or removing implements, ensure the hydraulic couplers and quick-connect fittings are clean and fully seated to avoid contamination and pressure loss. Regular maintenance should include filtering the hydraulic fluid, checking reservoir level, and confirming that return lines are unobstructed to maintain consistent performance under load. Maintain a log of hydraulic diagnostic results, noting any abnormal noises, overheating, or fluctuating pressures for proactive service planning.

Safety checks for attachments are a critical aspect of daily maintenance and operation. Before use, perform a visual inspection of all attachment points, pins, and locking mechanisms to ensure there is no looseness or excessive wear that could lead to disengagement in the field. Confirm that the PTO, if equipped, is disengaged during attachment and detachment procedures, and verify that shields and guards are in place and intact to protect nearby personnel. Check the implement’s working depth or height indicators and ensure that depth control devices are functioning correctly to prevent unintended soil disruption or crop damage. Engage proper ballast and ensure ballast distribution aligns with the center of gravity of the attached implement to minimize sway and enhance stability during transport. Finally, run a brief functional test with the tractor at low speed to confirm smooth operation of lift, tilt, and lower cycles, listening for unusual noises or resistance that could indicate misalignment or component wear requiring service.

Maintenance record and documentation

Effective maintenance relies on disciplined record keeping and consistent scheduling. A clearly maintained log helps you anticipate service needs, track component life, and plan preventive measures before failures occur. Begin with a centralized notebook or digital record that captures dates, service performed, parts replaced, and any observations noted during inspections. Establish a routine where technicians or operators review and update the records after every maintenance event or usage cycle. This practice not only supports reliable operation but also provides essential information for future troubleshooting and resale value.

Service history logging should be detailed and chronological, documenting each intervention with specificity. Include machine hours at the time of service, exact parts numbers, torque values used, and any diagnostic codes that were observed. When possible, attach photos or scanned invoices to the entry to provide visual evidence of condition and workmanship. Regularly review the log to identify recurring issues, mean time between failures, and trends that could indicate wear or misalignment. A well-maintained history enables technicians to learn from past experiences and optimize maintenance intervals for the AGCO ALLIS 1920H series equipment.

Warranty and service policies must be clearly understood and integrated into the maintenance program. Record warranty coverage details for each component, including expiration dates, limits, and required service intervals to maintain eligibility. Maintain copies of purchase receipts, warranty cards, and communications with the manufacturer or authorized dealers. When a warranty claim is necessary, ensure that all documentation is complete, accurate, and submitted within the specified time frame to avoid denial. Aligning routine service with policy requirements helps maximize the value of the warranty while ensuring compliant, traceable maintenance practices.