Your NH Workmaster 50 utility tractor requires regular maintenance at specific intervals to deliver reliable performance and reach its expected 5,000+ hour service life. Understanding service intervals, fluid capacities, and proper procedures prevents costly repairs and keeps your tractor working when you need it. This comprehensive guide covers every service interval with capacities, specifications, and detailed maintenance information.
The NH Workmaster 50 is New Holland’s popular 45-50 horsepower utility tractor, part of the Workmaster 40-75 series built for agricultural, municipal, and commercial applications. These versatile machines handle everything from hay production and livestock operations to grounds maintenance and light construction. Proper maintenance keeps them running reliably through demanding work.
What are Service Intervals?
NH organizes Workmaster 50 maintenance into hour-based intervals measured by the tractor’s hour meter. When both hour and time intervals are specified, perform maintenance at whichever comes first. A lightly-used tractor reaches annual intervals before hour intervals; heavily-used commercial machines hit hour intervals first.
The Workmaster 50 follows these primary service intervals:
- Daily or Every 10 Hours – Pre-operation checks
- Every 50 Hours or Weekly – Basic inspections and lubrication
- Every 100 Hours or Monthly – Chassis lubrication service
- Every 250 Hours or Quarterly – Comprehensive inspection
- Every 500 Hours or Annually – Major filter and fluid services
- Every 1,000 Hours or Every 2 Years – Transmission and hydraulic service
- Every 1,500 Hours or Every 3 Years – Coolant and comprehensive service
Fluid Capacities at a Glance
| System | Capacity | Specification |
|---|---|---|
| Engine Oil | 6.3 quarts (6 liters) | NH 410B or 15W-40 CJ-4 |
| Fuel Tank | 16.9 gallons (64 liters) | ULSD #2 diesel |
| Coolant System | 4.2 gallons (16 liters) | 50/50 extended life coolant |
| Transmission/Hydraulics | 13.2 gallons (50 liters) | NH 410B fluid |
| Front Axle (4WD) | 1.8 gallons (7 liters) | 80W-90 GL-5 or NH 410B |
| Rear Axle | Shared with transmission | NH 410B fluid |
| Power Steering | Shared with hydraulics | NH 410B fluid |
Daily/Every 10 Hours Service
These critical checks take 10-15 minutes and prevent breakdowns by catching problems early. Perform them before starting work each day or after every 10 operating hours.
Engine Oil Level
Check engine oil with the tractor on level ground and engine off for 5-10 minutes. The dipstick is on the right side of the engine. Pull it out, wipe it clean, reinsert fully, and pull again to read. Level should be between ADD and FULL marks.
If oil is low, add the correct specification (NH 410B or 15W-40 CJ-4 diesel oil) to bring it to FULL. Don’t overfill—excess oil causes foaming and seal damage. If you’re adding more than a quart between services, investigate for leaks or excessive consumption.
Coolant Level
Check the coolant overflow reservoir on the left side of the engine compartment. With the engine cold, level should be between MIN and MAX marks. If low, add 50/50 mixture of extended-life coolant and distilled water.
Never open the radiator cap when the engine is hot—pressurized boiling coolant causes severe burns. If coolant level drops repeatedly, inspect for leaks at hoses, clamps, water pump, and radiator.
Fuel Level and Water Separator
Check the fuel gauge and refill before getting below 1/4 tank. Running low allows sediment to enter the fuel system. After refueling, inspect the fuel water separator bowl (under the hood on the engine) for water accumulation—it appears as a distinct layer below the diesel.
If water is present, drain it by opening the valve at the bottom of the separator bowl. Water damages injection pumps and injectors costing thousands in repairs. Drain water every time you see it.
Air Cleaner Restriction Indicator
Check the air filter restriction indicator on the air cleaner housing. If the red indicator shows, the air filter needs service. Restricted air filters reduce power, increase fuel consumption, and allow contaminant entry.
Hydraulic/Transmission Fluid Level
Check hydraulic fluid level using the sight glass or dipstick on the left side of the transmission case. With the engine off and tractor on level ground after sitting 5 minutes, level should be in the middle of the sight glass or at FULL on the dipstick.
Low level indicates leaks. Check around hydraulic cylinders, lines, fittings, and the transmission case for wet spots or drips. Add NH 410B fluid if needed, but find and fix leaks promptly.
Visual Inspection
Walk around the tractor checking for:
- Fluid leaks (engine oil, coolant, hydraulic fluid, diesel fuel)
- Damaged hoses or wiring
- Tire condition and pressure
- Loose or missing components
- Debris around engine or radiator
- Operator controls and safety systems function
Address any issues before operating.
Every 50 Hours or Weekly Service
This service adds battery and cooling system checks to the daily maintenance. Budget 20-30 minutes for completion.
Battery Service
Inspect battery terminals for corrosion, tight connections, and cable condition. Clean corroded terminals with a wire brush and baking soda solution. Tighten loose connections. Check the battery case for cracks or damage.
If your NH Workmaster 50 has a conventional serviceable battery, check electrolyte level in each cell and add distilled water if needed to cover the plates. Maintenance-free batteries don’t require water addition.
Tire Pressure
Check tire pressure when tires are cold. Proper pressure varies by tire size and application, but typical pressures for the NH Workmaster 50 are:
- Front tires (4WD): 20-24 PSI
- Rear tires: 12-16 PSI
Refer to your operator’s manual for specific pressures for your tire configuration. Under-inflation causes excessive wear and poor stability. Over-inflation reduces traction and ride comfort.
Radiator and Screen Cleaning
Inspect the radiator screen and cooling fins for debris. Dust, chaff, leaves, and grass clippings block airflow causing overheating. Remove the screen and clean it. Blow out radiator fins with compressed air from the engine side outward, or wash gently with a water hose.
Clean the cooling system more frequently in dusty or high-chaff environments. Overheating causes head gasket failure, warped heads, and engine damage.
Fuel Filter Water Drain
Even if you checked during daily service, drain any water from the fuel water separator. Water contamination is progressive—what isn’t visible today may be tomorrow. Stay ahead of it.
Every 100 Hours or Monthly Service
This interval focuses on chassis and driveline lubrication. You’ll need a grease gun loaded with multi-purpose lithium or polyurea grease and 30-45 minutes.
Front Axle Lubrication (4WD Models)
If your NH Workmaster 50 has four-wheel drive, the front axle requires comprehensive greasing:
Front axle pivot pin – Center grease fitting where front axle attaches to tractor frame. Pump grease until you see purge from seals.
Steering cylinder pins – Grease fittings at steering cylinder attachment points (typically 2-4 fittings). Grease until purge.
Front wheel bearings – One fitting per front hub. Pump 3-5 shots per hub.
Front drive shaft U-joints – Two fittings on the front drive shaft. Grease until purge at bearing caps.
Front axle knuckles – Multiple fittings (2-4 per side) at the steering knuckles where wheels pivot. These are critical—inadequate greasing causes expensive wear. Grease thoroughly until purge at all points.
Three-Point Hitch Lubrication
Lift arm ball joints – Two fittings where lift arms connect to rockshaft. Grease until purge.
Check chains and stabilizers – Grease attachment points if equipped with fittings.
Leveling mechanism – One or two fittings on the leveling crank assembly. Pump 2-3 shots.
PTO Shaft
Apply grease to the rear PTO output shaft splines to prevent wear and ensure implement driveshafts slide freely. Wipe off excess to prevent dirt accumulation.
Loader Lubrication (If Equipped)
Loader attachment pins and pivot points require regular greasing. The exact number of fittings depends on your loader model, but typical points include:
- Loader attachment pins (2-4 fittings)
- Boom pivot points (2 fittings)
- Bucket pivot pin (1 fitting)
- Cylinder pins (4 fittings)
Grease all points until you see old grease purge from seals.
Pedal and Linkage Lubrication
Lubricate clutch pedal pivot, brake pedal pivots, throttle linkage, and any other control linkages with light oil or spray lubricant. This prevents binding and ensures smooth operation.
Every 250 Hours or Quarterly Service
This comprehensive inspection interval catches developing problems before they cause failures. Budget 45-60 minutes for thorough completion.
Transmission/Hydraulic Fluid Sampling
Pull a fluid sample from the hydraulic reservoir using a clean turkey baster or fluid extraction pump through the dipstick tube. Put a few drops on white paper towel and examine under good light.
Look for:
- Dark or black color – indicates overheating or age
- Milky or cloudy appearance – water contamination
- Metallic particles – internal wear
- Burnt smell – severe overheating
If fluid shows problems, change it immediately regardless of hours since last change.
Belt Inspection and Tension
Inspect all engine-driven belts (alternator, fan, air conditioning if equipped) for:
- Cracks or fraying on the edges
- Glazing or shiny surfaces
- Missing chunks or pieces
- Proper tension (1/2 inch deflection under moderate thumb pressure)
Replace worn or damaged belts. Adjust loose belts to proper tension per your manual’s specifications.
Hose and Clamp Inspection
Inspect all hoses (coolant, fuel, hydraulic, air intake) for:
- Cracks, splits, or bulges
- Hardening or soft spots
- Chafing against frame or components
- Loose or corroded clamps
Replace questionable hoses before they fail and leave you stranded.
Electrical System Check
Test all lights (headlights, taillights, work lights, turn signals, hazard lights, warning lights). Check safety switch operation—seat switch, neutral start, PTO engagement switch. Verify the charging system maintains battery voltage (should be 13.5-14.5 volts with engine running).
Hydraulic Cylinder Inspection
Inspect all hydraulic cylinders (three-point hitch, loader if equipped, steering, remotes) for:
- Fluid leaks at rod seals
- Damaged or scored piston rods
- Loose mounting pins
- Excessive play in bushings
Small seepage is normal; active dripping requires seal replacement.
Brake System Check
Test brake operation. Both foot brakes should apply evenly and hold the tractor securely. Parking brake should hold the tractor on a moderate slope. If brakes are weak, spongy, or uneven, inspect and adjust per your service manual.
Every 500 Hours or Annual Service
This major service interval includes engine oil and filter, fuel filter, air filter, and various fluid checks. It’s the most comprehensive regular service. Budget 2-3 hours and gather all parts before starting.
Engine Oil and Filter Change
Capacity: 6.3 quarts (6 liters) with filter
Oil specification: NH 410B or 15W-40 diesel oil meeting API CJ-4 or later
Filter part number: 87840591
Warm the engine by running 10 minutes, then shut it off. Position a drain pan under the drain plug on the bottom of the oil pan. Remove the plug (typically 19mm socket) and drain completely—about 15 minutes for 6+ quarts.
While draining, remove the oil filter with a filter wrench. It’s on the front-right side of the engine. Clean the filter mounting surface on the block.
Fill the new filter about half full with clean oil and coat the gasket with oil. Thread it on by hand until the gasket contacts the block, then tighten 3/4 turn more by hand.
Reinstall the drain plug with new crush washer if available. Tighten to 35-40 ft-lbs.
Fill the engine with 6 quarts of fresh NH 410B or 15W-40 CJ-4 oil through the filler cap. Start the engine, idle for 30 seconds, shut off, and wait 5 minutes. Check level and add to FULL mark (usually another 1/4 quart). Check for leaks.
Fuel Filter Replacement
Part number: 84477369 (primary fuel filter/water separator)
Turn the drain valve at the bottom of the fuel filter bowl to drain fuel and water. Once empty, close the valve. Use a filter wrench to remove the entire filter assembly.
Clean the mounting surface on the filter head. Fill the new filter 2/3 full with clean diesel fuel. Coat the gasket with fuel.
Thread the new filter on by hand until the gasket contacts, then tighten 1/2 turn more.
Prime the fuel system with the priming pump on the filter head (pump 20-30 times until firm resistance). Crank the engine—it should start within a few seconds. Check for leaks.
Air Filter Service
Outer element part number: 87682999
Inner element part number: 87682980
Remove the air filter cover and carefully remove the outer element. Inspect it for damage—tears, crushed pleats, damaged seal. If damaged, replace it. If intact, clean with compressed air (blow from inside out at low pressure) or replace.
Inspect the inner safety element but don’t remove it unless replacing. Replace the inner element every 1,000 hours or if the outer element was damaged.
Install the new or cleaned outer element. Reinstall the cover and reset the restriction indicator.
Hydraulic Filter Inspection
The hydraulic filter doesn’t change until 1,000 hours, but inspect it now for external leaks or damage. The filter is on the right side of the transmission case beneath the operator platform.
Coolant System Check
Inspect all coolant hoses and clamps for deterioration or leaks. Test coolant concentration with a refractometer or hydrometer—should be 50/50 for -34°F freeze protection. Check coolant pH with test strips—should be 8.0-11.0. If concentration is off or PH is low, service the coolant system.
Front Axle Fluid Check (4WD)
If your NH Workmaster 50 has four-wheel drive, check the front axle differential fluid level. Remove the fill plug on the side of the front axle center housing—fluid should be at the bottom of the fill hole. If low, add 80W-90 gear oil or NH 410B until it runs out.
Every 1,000 Hours or Every 2 Years Service
This major service includes transmission/hydraulic fluid and filter change. Most owners have this done professionally due to the fluid quantity (13+ gallons of expensive NH 410B) and complexity.
Transmission and Hydraulic Fluid Change
Capacity: 13.2 gallons (50 liters) total system
Fluid specification: NH 410B hydraulic/transmission fluid
Filter part number: 84565925
Warm the tractor by operating 15-20 minutes to bring fluid to operating temperature. Park on level ground and shut off the engine.
Locate the drain plug on the bottom of the transmission case (underneath, typically center-rear). Position a large drain pan or container with 15+ gallon capacity.
Remove the drain plug and let the system drain completely—45-60 minutes for 13+ gallons. While draining, cycle the three-point hitch, loader, and remote valves with the engine off to push fluid from cylinders back to the reservoir. Move the range selector through all positions.
Once drained, reinstall the drain plug with new crush washer. Tighten to spec (typically 40-45 ft-lbs).
Hydraulic Filter Replacement
Remove the old hydraulic filter with a filter wrench. Clean the mounting surface. Fill the new filter about 1/3 full with clean NH 410B and coat the gasket with fluid. Thread it on by hand until gasket contact, then tighten 3/4 turn more.
Refilling and Bleeding
Fill the transmission/hydraulic reservoir through the filler opening on the left side beneath the operator platform. Pour slowly—13 gallons is substantial volume. Use the dipstick to monitor level and fill to FULL.
Start the engine and let it idle. Slowly move the range selector through all positions—forward, reverse, neutral. Operate the three-point hitch and loader (if equipped) through full range 5-6 times to circulate fluid and purge air.
Shut off, wait 10 minutes, recheck level. It will have dropped as fluid filled lines and components. Add to restore FULL level. Repeat until level stabilizes.
Front Axle Differential Service (4WD)
Capacity: 1.8 gallons (7 liters)
Fluid specification: SAE 80W-90 GL-5 gear oil or NH 410B
Drain the front axle differential by removing the drain plug at the bottom of the center housing. Let it drain completely. Clean the magnetic drain plug and reinstall.
Fill through the fill plug opening on the side of the housing until fluid runs out—this indicates proper level. Install the fill plug.
Use 80W-90 GL-5 gear oil for most conditions. In extreme cold, NH 410B flows better and is acceptable.
Inner Air Filter Replacement
Replace the inner safety air filter element at 1,000 hours even if it looks clean. This element is your last line of defense against engine contamination—don’t risk it.
Every 1,500 Hours or Every 3 Years Service
This comprehensive service includes coolant system service and thorough inspection of all major systems.
Cooling System Flush and Refill
Capacity: 4.2 gallons (16 liters)
Coolant specification: Extended-life ethylene glycol coolant 50/50 with distilled water
With the engine cold, remove the radiator cap. Open the radiator drain cock at the bottom and drain coolant into a proper container. Dispose of used coolant properly—it’s toxic.
Close the drain cock and fill with clean water. Run the engine to operating temperature, then drain. Repeat to flush old coolant and contaminants completely.
Fill with fresh 50/50 coolant mixture. Fill the radiator to the base of the filler neck. Start the engine with the cap off and let it warm to operating temperature, adding coolant as air purges. Once the thermostat opens and coolant circulates, shut off the engine.
Let it cool slightly, top off the radiator, and install the cap. Fill the overflow reservoir to MAX.
Comprehensive System Inspection
Thoroughly inspect:
- Clutch operation and adjustment
- Transmission shifting and response
- Hydraulic system performance and response time
- Three-point hitch operation and control
- PTO engagement and operation
- Steering system for wear or play
- Brake adjustment and performance
- All safety systems and interlocks
- Electrical charging and starting systems
- Engine performance and emissions
Address any identified issues. At 1,500+ hours, wear items may need attention or replacement.
Severe Service Adjustments
Reduce maintenance intervals by 25-50% for severe service conditions:
Dusty environments – Change air filters more frequently (every 250 hours), inspect engine breather, clean cooling system every 25 hours.
High temperatures – Monitor coolant closely, change transmission/hydraulic fluid more frequently (every 750 hours), inspect cooling system regularly.
Heavy loads/continuous use – Reduce oil change to 400 hours, monitor all fluid temperatures, inspect drivetrain more frequently.
Commercial/high-hour applications – Follow hour-based intervals regardless of time. Implement fluid analysis programs to optimize intervals.
Filter and Fluid Part Numbers Summary
| Component | Part Number | Specification | Interval |
|---|---|---|---|
| Engine Oil Filter | 87840591 | – | 500 hrs/Annual |
| Fuel Filter | 84477369 | Primary/water separator | 500 hrs/Annual |
| Air Filter (Outer) | 87682999 | – | 500 hrs |
| Air Filter (Inner) | 87682980 | – | 1,000 hrs |
| Hydraulic Filter | 84565925 | – | 1,000 hrs/2 Years |
| Engine Oil | – | NH 410B or 15W-40 CJ-4 | 500 hrs/Annual |
| Hydraulic Fluid | – | NH 410B | 1,000 hrs/2 Years |
| Coolant | – | Extended-life 50/50 | 1,500 hrs/3 Years |
| Front Axle Fluid | – | 80W-90 GL-5 or NH 410B | 1,000 hrs/2 Years |
| Grease | – | Multi-purpose NLGI #2 | 100 hrs/Monthly |
Quality aftermarket filters meeting OEM specifications are available from FridayParts at competitive prices. Our filters protect your NH Workmaster 50 without dealer markup.
Frequently Asked Questions
Can I use synthetic oil in my NH Workmaster 50?
Yes, synthetic 15W-40 diesel oil meeting API CJ-4 or later works well. Synthetic provides better protection in temperature extremes but doesn’t eliminate the need for regular changes. Follow the same 500-hour interval unless oil analysis confirms safe extension.
What happens if I skip a service interval?
Perform the missed service as soon as possible. Occasional slightly late service won’t destroy your tractor, but consistent neglect causes accelerated wear and eventual expensive failures. If significantly overdue, consider shortening the next interval to compensate.
Can I extend intervals to reduce maintenance costs?
Only with professional fluid analysis confirming fluids remain serviceable. For most operations, recommended intervals already balance protection and cost effectively. Extending intervals risks expensive damage to save modest maintenance costs—not a good trade-off.
Why is NH 410B fluid required instead of generic hydraulic oil?
NH 410B is formulated specifically for powershift transmissions, wet brakes, hydraulic systems, and final drives. It has friction modifiers for smooth shifting, anti-wear additives for pumps, and proper viscosity for cold weather. Generic hydraulic oil lacks these properties and causes transmission problems.
How do I know if my tractor qualifies for severe service intervals?
If you operate in very dusty conditions, sustained high temperatures (95°F+), with continuous heavy loads, or accumulate more than 500 hours annually, use severe service intervals. When in doubt, shorter intervals provide better protection.
Following the proper service intervals keeps your NH Workmaster 50 operating reliably for thousands of hours. Regular maintenance prevents expensive failures and maintains optimal performance. FridayParts stocks filters and maintenance parts for your Workmaster at prices that make sense. We’ve got what you need to keep your New Holland running right.
