Hedgecutters and flails · PA93 from about 1987 (handbook 1992); PA55/PA60 Mk1 from 2004
Covers the McConnel Power Arm hedgecutter (PA55 / PA60 Mk1 and PA93 / PA9058).
Every maker's service job for the McConnel Power Arm hedgecutter, 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.
Versions: PA55 / PA60 Mk1 (Si semi-independent or Ti totally independent hydraulics); PA93 / PA9058 series (older, spring-assisted gravity breakaway)
Service intervals
Job
When
PTO shaft sliding tubes and guards
every 100 hours
PTO gearbox oil change
every 500 hours or every year
Hydraulic return filter change (and oil if it has gone off)
every 500 hours
Storage
every year
Flails, flail bolts and rotor bearings
when needed
Breakaway check (and auto-reset setting on front-mount PA55/PA60)
when needed
Hydraulic hoses and cables
when needed
Service jobs and parts
PTO shaft sliding tubes and guards
PTO shaft · every 100 hours
PA93 handbook: grease the universal joints very sparingly (one shot weekly), lightly grease the guard's nylon slip rings weekly, and separate the shaft and grease the inner tube about every 100 hours. Check daily that both guard halves spin freely.
Part
Qty
Notes
Part number
Lithium grease
1
check your handbook
Step-by-step
Disengage the PTO, stop the tractor and take the key out.
Pull the shaft halves apart, clean the inner tube and grease it.
Give each universal joint one shot only. Over-greasing blows out the needle bearing seals.
Lightly grease the nylon guard slip rings and check both guard halves turn freely. Check the anti-rotation chains and their anchor points.
Do not use the machine with a damaged guard.
Tools: Grease gun, Rag
PTO gearbox oil change
Gearbox · every 500 hours or every year
PA55/PA60: change after the first 50 hours, then every year or 500 hours, whichever comes first, with 0.5 L of SAE 80 or ISO 100. PA93: change every year or 600 hours with 0.25 L of SAE 30/50 universal tractor oil.
Part
Qty
Notes
Part number
Gear oil (PA55/PA60)
1
SAE 80 or ISO 100, 0.5 L
check your handbook
Universal tractor oil (PA93)
1
SAE 30/50, 0.25 L
check your handbook
Bonded seal for gearbox plug (PA55/PA60 Ti pump and gearbox)
1
Listed on the Ti pump and gearbox page; check it fits your plug
8650104
Step-by-step
Lower the head, disengage the PTO, stop the tractor and take the key out.
Drain the gearbox while the oil is warm.
Refill with the right oil until it is level with the filler plug hole, then refit the plug.
On a new PA55/PA60, make the first change at 50 hours.
Tools: Small drain tray, Spanners, Funnel
Hydraulic return filter change (and oil if it has gone off)
Hydraulics · every 500 hours
McConnel says change the return line filter element after the first 50 hours and then every 500 hours. A blocked element goes into bypass with no warning, so log the hours. McConnel gives no fixed oil change: change the oil when it smells burnt, darkens or thickens, or has taken in water, and always fit a new element when you do.
Part
Qty
Notes
Part number
Return filter element (PA55/PA60)
1
In return filter head 8401041; O-ring 43175.01 on the tank fittings
8600151
Return filter element (PA93)
1
Number not found; check your handbook
check your handbook
Hydraulic oil ISO 46 (ISO 68 hot climates)
1
Only if the oil is being changed: ≈200 L. Aztec Oils match: HYDRATEC HM 46
check your handbook
Step-by-step
Lower the flail head to the ground, disengage the PTO, stop the tractor and take the key out.
Clean around the filter head and the reservoir cap before opening anything. Dirt is the main cause of pump and motor damage.
Change the return line element. On a new machine do this at 50 hours, then every 500 hours.
Check the oil. If it smells burnt, is dark and thick, or looks milky from water, drain the tank and refill with fresh oil of the right grade. Water cannot be filtered out.
If the pump has been cavitating or the controls feel spongy, drain the tank and flush it with clean diesel: the suction strainer is fixed in the tank and cannot be taken out.
Refill to about 50 mm below the top of the tank. Run the PTO for about 5 minutes with the rotor off so the oil passes through the return filter, then recheck the level.
Tools: Filter wrench or spanners, Clean drip tray, Clean rags, Clean oil container and funnel
Storage
Storage · every year
McConnel's dismounting notes: grease the exposed parts of the ram rods before standing the machine, and wipe the grease off before the rams are used again.
Part
Qty
Notes
Part number
Grease
1
check your handbook
Step-by-step
Park on firm level ground on the parking stands, with the head on the ground at half reach.
Disconnect the PTO shaft and stow the control unit somewhere dry.
Coat the exposed ram rods with grease. Wipe it off before the rams are next moved.
Grease all points and check the hoses before putting it away.
Tools: Grease gun, Rags
Flails, flail bolts and rotor bearings
Flail head · when needed
McConnel says inspect the rotor often for damaged or missing flails, keep the flail nuts tight (135 Nm on the PA93 head), check the pivot bushes, and keep the bearing housing and motor mounting bolts tight. Running with flails missing wrecks the rotor bearings.
Lower the head to the ground, disengage the PTO, stop the tractor, take the key out and wait for the rotor to stop.
Check every flail. A broken or lost flail must be replaced with the one opposite it to keep the rotor in balance. Never pair a new flail with a re-sharpened one.
As a short-term fix only, take off the flail opposite a lost one so the rotor stays balanced.
Check the flail bolts and nuts. On the PA93 head the locknuts are 135 Nm. Use only the correct flail bolt and locking nut.
Check the flail pivot bushes for wear. They need no oil.
Sharpen blunt flails with a grinder, wearing protective gear. Blunt flails take a lot of power and leave a ragged cut.
Check the bearing housing bolts and the motor mounting bolts are tight.
Tools: Torque wrench, Sockets and spanners, Grinder for sharpening, Eye protection and gloves
Breakaway check (and auto-reset setting on front-mount PA55/PA60)
Arms · when needed
The breakaway protects the arms. On the PA55/PA60 it works by the slew relief valve at the slew column pivot. Front-mounted machines have a valve tap for setting the auto-reset pressures, and a test point on the breakaway ram for checking pressure or bleeding air. The PA93 spring breakaway is set at the factory and cannot be adjusted.
Step-by-step
With the arm in the work position, check the breakaway lets the arm swing back and resets. Never drive on to drag the head round an obstacle.
PA55/PA60 front mount: place the head horizontal, close to the tractor and resting on the ground. Open the valve tap, raise the head clear of the ground and lower it again, then close the tap. The pressures set themselves.
If the breakaway feels soft or uneven, bleed air or check pressure at the test point on the breakaway ram.
After a breakaway in Slew mode, reverse the slew so the relief valve reseats.
PA93: on high hedges on sloping ground, keep the latch lowered as an abutment stop, as McConnel warns the head can become unstable when broken back at full height.
Tools: Pressure gauge for the test point (if checking pressure)
Hydraulic hoses and cables
Hydraulics · when needed
McConnel says check all hoses at each routine service, tape chafed outer covers to stop the braid rusting, and change hoses with damaged braid. Soft-seal nuts hold pressure when only finger tight, so flex the hose to relieve pressure before taking it off. Cables must never be oiled.
Step-by-step
Lower the head, stop the tractor and take the key out.
Check each hose, especially the flail hoses crossed at the dipper and head pivots.
Replace one hose at a time, routed exactly as before, with no jointing compound and no twist.
Tighten soft-seal nuts to the chart: for example 1/2" BSP 44 Nm, 3/4" BSP 84 Nm.
Check the control cables for kinks or damage and seal any damaged outer casing with tape. Do not lubricate them.
Tools: Two spanners, Waterproof tape, Torque wrench
Oils, fluids and capacities
System
Oil or spec
Capacity
Hydraulic reservoir
Cold or temperate climate: ISO 46 hydraulic oil (for example BP Bartran 46, Castrol Hyspin AWH-M 46, Shell Tellus 46 class). Hot climate: ISO 68 grade
≈200 L (44 gal). Fill to about 50 mm below the top of the tank
PTO gearbox (PA55/PA60)
SAE 80 or ISO 100 gear oil
0.5 L
PTO gearbox (PA93)
SAE 30/50 universal tractor oil
0.25 L (½ pint). Level with the filler plug hole
Grease points and PTO shaft
General purpose lithium grease
Specifications
Hydraulic filtration
125 micron suction strainer fixed inside the tank; 10 micron low-pressure full-flow return line filter
Breakaway (PA55/PA60)
Hydraulic, at the slew column pivot; Auto-Reset or Slew mode
Breakaway (PA93)
Spring-assisted gravity breakaway; spring preload set at the factory and not adjustable
PA55/PA60: 95° working arc (108° quoted in the features list)
Known problems
Return filter in bypass
The return filter has an internal bypass, so a blocked element gives no symptoms. Change it by the hours, not by feel.
Wire round the rotor
Stop the rotor, stop the engine and take the key out before cutting wire off. McConnel says do not reverse the rotor to unwind it.
Repair guides
Burst or chafed hydraulic hose: replacing a hose (Moderate, 30 minutes to 2 hours per hose, depending on where it runs): Oil spraying or pouring from the arm, a sudden drop in the tank level, the head or an arm service stops working, or a hose with its outer cover worn through to the wire braid.
Breakaway not working or not resetting (Moderate, 30 minutes to check; longer if air must be bled or pressures checked): The arm does not swing back when the head hits a post or tree, it swings back too easily, it will not come forward again afterwards, or it feels soft or jerky when it resets.
Hydraulics noisy, spongy or overheating: pump cavitation and oil condition (Moderate, Half a day to drain, flush and refill): Pump whines or rattles, arm movements are spongy or come and go, the rotor slows or stops while the pump keeps running, or the oil smells burnt, has gone dark and thick, or looks milky.
Flail head vibration: flails, flail bolts and rotor bearings (Moderate, 1–2 hours for a set of flails; 3–4 hours for rotor bearings): Head shakes or the arm vibrates, a ragged cut, a flail missing or broken, rumbling or hot rotor bearings, or a rotor that will not turn freely by hand.
The full step-by-step guides are in Farmyard Workshop once you add your implement.
Parts list with genuine part numbers
McConnel PA55/PA60 Mk1 parts manual (rev. 07.11.08; only the pages whose assembly title could be read) and the 1.2 m Multicut sliding head quad drive parts manual (rev. 26.09.22). PA93/PA9058 owners: see the PA93 SS book on the PA48 / PA93 SS / PA96 entry.
PA55/PA60 Mk1: Stabiliser Assembly
Part
Part number
Qty
Notes
Stabiliser assembly
7155718
1
Stabilizer
41205.03
1
Tongue - cat.2
7499501
1
Bolt
9213228
2
Self-locking nut
9143008
2
Top link assembly - heavy duty
21370.01
1
Top link pin
43342.01
1
Linch pin
0431217
1
Quadrant pin
45784.01
1
Spring cotter
0431105
1
Bolt
9213149
2
Self-locking nut
9143009
2
Pto hook
21160.03
1
Plastic insert
21388.01
4
PA55/PA60 Mk1: Rocker Assembly - Standard
Part
Part number
Qty
Notes
Rocker assembly - standard
7452710
1
Rocker
45059.02
1
Bush
08.297.02
4
Pin cap
45266.01
4
Bolt - button / socket head
9300159
6
Slew rod pin
45202.04
3
Setscrew
9313075
3
Self-locking nut
9143005
3
GREASE NIPPLE - Straight
0901121
7
Retaining bracket
43048.06
1
Hook
43048.05
1
Setscrew
9313044
2
Spring washer
9100204
2
Main pivot pin
45264.01
1
'o' ring 225
8600303
4
Plastic plug
42964.02
2
Socket button screw
9300161
2
PA55/PA60 Mk1: PA55 Hose Kit - L/H Cable SI
Part
Part number
Qty
Notes
Pa55 hose kit - l/h cable si
71557221
1
PA55/PA60 Mk1: PA55 Hose Kit - L/H Cable TI
Part
Part number
Qty
Notes
Pa55 hose kit - l/h cable ti
71557222
1
PA55/PA60 Mk1: PA55 Hose Kit - L/H Electric (Cable RCV)