Hardi NK / NV service schedule

Sprayers · 2002 book (673635-GB-05/2002); new-generation NK on sale 2026

Covers the Hardi NK / NV (mounted).

Every maker's service job for the Hardi NK / NV, counted in hours, with the oils, filters and parts each one needs. Add your implement to Farmyard Workshop and it works out what's due from your hours and dates, and keeps the service history.

Track your NK / NV for free

Versions: NK 300–800 / NV 600–800 (2002 book: pumps 600, 1202 or 1302); New-generation NK 600–1000 (Hardi 364 pump, 140 L/min)

Service intervals

Job	When
Grease PTO shaft cross journals (every 12 hours)	every 12 hours
Oil the BK operating unit (every 20 hours)	every 20 hours
Grease all points (every 40 hours)	every 40 hours
Off-season storage and frost protection	every year
Sprayer test (NSTS)	every 3 years
Clean the sprayer and filters after each job	when needed
Pump valves and diaphragms	when needed

Service jobs and parts

Grease PTO shaft cross journals (every 12 hours)

PTO shaft · every 12 hours

The NK book's table gives 12 hours for the PTO cross journals (point 2A). The older MASTER book says 8 hours, so do not stretch it.

Part	Qty	Notes	Part number
Grease	1	NLGI 2 lithium grease.. Aztec Oils match: VOLCATEC LITHIUM EP 2	check your handbook

Step-by-step

Disengage the PTO, stop the tractor engine and take the key out. Wait until the shaft has stopped turning.
Grease each cross until fresh grease shows at the seals.
Check the guards turn freely and both chains are fitted.

Tools: Grease gun

Oil the BK operating unit (every 20 hours)

Controls · every 20 hours

The NK table marks the BK operating unit (point 3) for oil every 20 hours.

Part	Qty	Notes	Part number
Light oil	1	Grade not given; check your handbook	check your handbook

Step-by-step

Stop the tractor engine and take the key out. Wear chemical-resistant gloves.
Oil the moving parts of the operating unit shown in the book, then wipe off surplus.
Wash gloves before taking them off and wash your hands.

Tools: Oil can, Rags

Grease all points (every 40 hours)

Lubrication · every 40 hours

Hardi's NK lubrication table gives 40 hours for the pump, the PTO shaft sliding tubes and the boom height-adjustment frame. Grease the whole machine after pressure washing or fertiliser.

Part	Qty	Notes	Part number
Grease	1	NLGI 2 lithium grease.. Aztec Oils match: VOLCATEC LITHIUM EP 2	check your handbook

Step-by-step

Lower the sprayer to the ground, disengage the PTO, stop the tractor engine, take the key out and wait for the shaft to stop.
Wear chemical-resistant gloves and wipe each nipple clean first.
Grease the pump crankshaft nipple(s), the PTO shaft sliding tubes and the boom height frame and pivots.
Wipe off surplus. Wash gloves before taking them off and wash your hands.

Tools: Grease gun, Rags

Off-season storage and frost protection

Storage · every year

Hardi's NK storage list: clean out all chemical, check hoses, touch up paint, slacken the safety valve spring on the operating unit, check the shaft guards, and fill the system with anti-freeze if not stored frost-free.

Part	Qty	Notes	Part number
Anti-freeze	1	At least 10 L of 33% mixture	check your handbook

Step-by-step

Wear chemical-resistant gloves and eye protection and clean the sprayer fully.
Disengage the PTO, stop the tractor engine and take the key out whenever you work near the pump or shaft.
Check all hoses; change any that are kinked, chafed or doubtful.
Touch up chemical-damaged paint. A film of anti-corrosion oil on metal parts (Hardi names Castrol Rustillo or Shell Ensis Fluid) keeps it clean.
Slacken the operating unit safety valve fully so its spring is not loaded over winter.
Check the PTO shaft shields and tubes are intact.
If not stored frost-free: put at least 10 litres of 33% anti-freeze in the tank and run the pump a few minutes so the whole system and spray lines are full.
Remove the glycerine-filled pressure gauge and store it frost-free and upright.
Wash gloves before taking them off and wash your hands.

Tools: Bucket, Wire brush, Touch-up paint, Grease gun

Sprayer test (NSTS)

Legal · every 3 years

UK law (SI 2012/1657 reg. 11) says a boom sprayer over 3 m in professional use must be inspected before it is 5 years old and at least every 3 years after that. Every NK boom (6–12 m) is over 3 m.

Step-by-step

Book a test with an NSTS test centre (nsts.org.uk) before the certificate runs out.
Wear the PPE the last chemical label asked for: chemical-resistant gloves and eye protection at least. Wash gloves before taking them off and wash your hands afterwards.
Clean the sprayer inside and out, including filters and nozzles.
Check the PTO shaft guards and chains, hoses, gauge and nozzles are sound and matched.
Keep the certificate and fix the sticker on the sprayer. Diary the next due date.

Tools: Pressure washer, Nozzle brush, PPE as the last chemical label says

Clean the sprayer and filters after each job

Spray system · when needed

Hardi says clean straight after use; there is no hour interval. On the NK the pressure filter is flushed by opening the drain valve with clean water circulating, so it need not be taken apart each time.

Part	Qty	Notes	Part number
Detergent or deactivating agent	1	As the chemical label says	check your handbook

Step-by-step

Wear the PPE the chemical label asks for and work away from drains and watercourses.
Dilute the remains with at least 10 parts water and spray it out on the crop just treated.
Stop the pump and clean the suction filter at the top of the tank (clip, hose fitting, guide, filter). Check its O-ring is sound and lubricated.
With clean water circulating, open the drain valve to flush the pressure filter.
Rinse the tank with detergent water, operate every valve, drain and let the pump run dry. Rinse again.
Clean nozzles with a soft brush, never wire, and never blow through them by mouth.
Wash gloves before taking them off and wash your hands and face.

Tools: Clean water, Nozzle brush, Chemical-resistant gloves, Eye protection

Pump valves and diaphragms

Pump · when needed

No fixed interval in the book: change them when the pump loses output or liquid comes from the drain hole under the pump. Hardi recommends new gaskets whenever the valves are checked.

Part	Qty	Notes	Part number
Diaphragm (membrane), 1302 pump only	1	Per diaphragm; count on your pump. Number from a parts dealer listing; confirm with your dealer	33511300
Diaphragms for 600, 1202 or 364 pump	1	Check your handbook	check your handbook
Valve cover gaskets	1	Check your handbook	check your handbook

Step-by-step

Clean and rinse the sprayer first. Lower it to the ground, disengage the PTO, stop the engine, take the key out and wait for the shaft to stop.
Wear chemical-resistant gloves and eye protection.
Remove the valve covers and note which way each valve faces before taking it out.
Remove the valve cover first, then the diaphragm cover, and change the diaphragm.
If liquid reached the crankcase, re-grease the pump thoroughly and check the drain hole is clear.
Refit with new gaskets and tighten to the torques in your handbook. Test with clean water before using chemical.

Tools: Spanners and sockets, Torque wrench, Chemical-resistant gloves, Eye protection

Oils, fluids and capacities

System	Oil or spec	Capacity
Grease points	Ball bearing grease (lithium grease No. 2)
Operating unit (BK)	Oil (grade not given: check your handbook)
Frost protection	33% anti-freeze mixture	At least 10 L in the tank, pumped through the whole system
Rinse tank (new-generation NK)	Clean water	72 L (600 L model); 110 L (800 and 1000 L models)

Specifications


Tank sizes (2002 book)	NK 300, 400, 600, 800 L; NV 600, 800 L
Tank sizes (new-generation NK)	600, 800 or 1000 L, MB boom 10 or 12 m
Booms (2002 book)	SB 6, 8, 10 or 12 m (NK); HFM or MB 10–12.5 m (NV)
Pump	2002 book: Hardi 600, 1202 or 1302 diaphragm. New generation: Hardi 364, 140 L/min
Linkage	Category I (22 mm pins); conversion kit 833707 for Cat. II (not 800 L model)
Filters (standard)	Suction filter 30 mesh; pressure filter 50 mesh; nozzle filters 50 mesh
PTO shaft	At least 150 mm overlap; cone-type shafts: Allen screw 40 Nm, recheck after 2 minutes
Weight (new-generation NK)	215–270 kg empty
Sprayer test (NSTS)	Booms over 3 m (all NK booms): every 3 years, first test before it is 5 years old

Known problems

Pump changed on the new NK

The new-generation NK has the Hardi 364 pump (140 L/min) instead of the older 600/1202/1302 pumps, so diaphragm kits differ. Give the dealer your serial number.

Front ballast

Hardi warns to add front ballast: a full mounted tank takes weight off the tractor's front wheels.

Suction side air leaks

A dry or damaged O-ring on the suction filter fitting is the usual cause of the pump losing prime.

Repair guides

No spray, low or jumping pressure: suction air leaks and blocked filters (Easy, 30–60 minutes): Nothing comes out of the boom when it is switched on, pressure low or falling, gauge needle jumping, pump losing prime near the end of a tank, foam in the tank.
Liquid from the pump drain hole: diaphragm and valve replacement (Moderate, 2–3 hours): Spray liquid or milky grease dripping from the hole under the pump, pump output falling, pressure will not build, pump sucking air after a rebuild.
Worn or blocked nozzles and filters (uneven spray, streaks) (Easy, 1 hour): Striping in the crop, one nozzle spraying less or more than its neighbours, a nozzle dribbling, pressure creeping up as a tank empties, output above the chart.
Sprayer calibration (owner check with a jug and stopwatch) (Easy, 1 hour): Running out of spray before the field is done, or having liquid left over; new nozzles fitted; different forward speed or rate needed; start of the season.
Pressure regulator and operating unit faults (dripping nozzles, sections won't switch) (Moderate, 1–2 hours): Nozzles keep dripping with the main ON/OFF valve shut, pressure jumps when a section is closed, a boom section will not open or close, electric (EC) operating unit dead.
Boom breakaway too stiff or too loose, boom out of line or yawing (NK, NV and ATV booms) (Moderate, 30 minutes (ATV) to 2 hours (NK/NV)): Boom swings forward and back when spraying, breakaway doesn't give when it hits something, wing folds back on small bumps or stays swung back, wing doesn't line up with the centre, hinge stiff to fold, HFM wing drooping.
Leaking hoses, nozzle bodies and boom fittings (Easy, 30–60 minutes): Drips from nozzle bodies or boom tube joints, wet patches along the boom, a hose weeping at a clip, spray delayed mid-job by a split hose.
Frost damage: split pump, valves or gauge, and frost-proofing (Moderate, 1–2 hours (plus parts)): After a frost: pump leaking from a cover, cracked valve housing or filter bowl, gauge needle stuck or glycerine leaking, no pressure on the first fill of spring.
PTO shaft guard and cross journal replacement (mounted Hardi sprayers) (Moderate, 1–2 hours): Split or missing shaft guard, guard tube not turning freely on the shaft, chains broken, play or clicking in a universal joint, cone-type shaft loose on the pump.
Ordering pump kits and parts: identify your pump and manual first (Easy, 20 minutes): Diaphragm kit doesn't fit, parts numbers in the book don't match the dealer's, sprayer bought second-hand with no paperwork, North American manual with US part numbers.
Tractor light on the front with a full NK: ballast and handling (Easy, 30 minutes): Steering goes light or the front wheels lift with a full tank, poor braking with the sprayer full, tractor pitching on bumps.

The full step-by-step guides are in Farmyard Workshop once you add your implement.

Parts list with genuine part numbers

Partao listings quoting Hardi numbers for NK/Master/Mega pumps; no Hardi parts book read

Pump

Part	Part number	Qty	Notes
Pump filter, type NK	845095	1	Wear part. Genuine number per Partao listing (fits Commander, Navigator, Ranger, Master, Mega and others)
Pump service kit for NK, Master, Mega and Ranger diaphragm pumps	75084000	1 kit	Wear part. Genuine number per Partao; contents not listed by source, check against pump model

Sources

Open Farmyard Workshop