Pruner: Bar Oiler Doesn't Work

The gears run off the drive shaft, turning the oil pump for the oiler. If these gears become damaged in any way they can cause the oiler to not work. To check the operation of these gears, follow the procedure under “Oil Pump” above to access the gears, as they are all together in the same unit. Once inside the gear housing, take out the gears and inspect them for any kind of damage such as worn out teeth, broken teeth, or anything out of the ordinary. When replacing these gears, make sure to lubricate them with grease. Finally, re-assemble the pruner head following the steps for reassembly listed under “Oil Pump”.

The oil pump runs off gears from the drive shaft, pumping oil from the tank to the bar. If you notice the chain is dry and the tank is full, your pump may not be working. To replace the oil pump, start by draining the oil from the tank, then removing the locking nut, and unscrewing the knob, locking it to the lower drive shaft. Press the alignment pin in to release the drive shaft, and remove the shaft. Remove the nut holding the sprocket cover in place. Next, remove the chain bar and chain. Remove the oil tank screws and tank, and then use a small flat-blade screwdriver to remove the oil fitting from the tank. Remove the center screw, loosen the outer screws, and remove the shaft. Remove the snap ring on the sprocket and remove the sprocket and washer. Remove all the remaining screws on the gear case housing and pull apart. Remove the main drive gear, the sprocket gear and remove the old oil pump assembly. Install the new oil pump by inserting the barrel into the oil block and aligning the holes. Insert the plunger into the barrel and align the pump assembly into the housing. Re-install the sprocket gear and rotate to make sure it turns the pump. Re-install the main drive gear and lubricate with grease. Re-assemble the gear housing, leaving the 2 screws a little loose by the drive shaft. Next, re-install the washer and sprocket. Re-install the snap ring onto the sprocket. Re-install the lower drive shaft into the pruner head and align the center screw and tighten down, then tighten down the 2 outer screws. Install a new fitting on the oil tank and re-install the oil tank. Re-install the chain around the sprocket and align the chain bar onto the mounting bolts. You might need to back off the tension on the tension screw to properly align the tensioner into the hole in the chain bar. Reinstall the cover, hand-tighten, then tighten the tension adjuster screw until there’s no slack in the chain, then finish tightening the cover down. Make sure the chain is tight but moves freely. Make any adjustments if needed. Then re-insert the lower drive shaft back with the upper drive shaft. Make sure the alignment pin snaps into place, then re-tighten the locking nut and handle.

The cap holds all the oil in the tank of the pruner, preventing leaks. If the cap is cracked or leaking it can allow all the oil to escape, preventing the oiler from working. Check the cap and replace it if you observe any such cracks. If the O-ring inside the cap is leaking, then it should be replaced instead.

The bar provides a channel for the chain to rotate on. The bar should be cleaned regularly to allow the flow of oil to get around the bar for the chain. If it is gummed up with dirt and debris, this will reduce or stop the flow of oil. Remove the nut on the cover of the pruner head, then lift off the chain bar and chain. Clean the bar channel with a brush to remove any debris, then re-assemble the bar and chain back onto the pruner head with the chain around the sprocket. Re-install the cover. You may need to back off the tension on the tensioner to properly align it into the hole in the chain bar. Then adjust the tension on the chain – the chain should be tight enough to spin with one hand and the drive teeth should not come out of bar nose. Finally, tighten the nut on the cover and re-check the chain’s tension.