Power trowel maintenance: oil, V-belt and blades

The guide is based on Swepac's Norwegian operating instructions for the petrol models TR 600P, TR 750P and TR 950P, and for the electric models TR 600E and TR 950E. The points on the V-belt, blades and storage apply to both types.

Safety before maintenance

During maintenance or blade changes, the engine can run on or start unexpectedly, especially when it is warm and the switch is on. Let the engine cool down, turn the switch to the off position and remove the spark plug cap. The engine, exhaust pipe and base get hot during operation, so wait until they have cooled down.

Daily checks on the petrol models

• Fuel: top up as needed. The operating instructions specify standard-grade unleaded petrol
• Oil level: check in the crankcase every day. The oil should reach the edge of the filler hole when the machine is on level ground. The engine oil should be SAE 10W/30
• Leaks: if the engine is leaking oil or fuel, the machine must not be used until the fault has been rectified
• Air filter: check at least once every working week, and daily in dusty conditions

Before starting, also check that the controls work and that bolted joints are tight. Warm up the engine for approx. 5 minutes.

The air filter

The air filter has a paper element and a foam element. To clean it:

• Remove both elements and check that they are undamaged. Replace damaged parts
• Wash the foam element in a liquid with a high flash point and let it dry thoroughly. Then dip it in engine oil and wring it out
• Tap the paper element against a hard object a couple of times to loosen dirt

V-belt and rubber dampers

Check the tension and condition of the V-belt regularly, and replace a damaged belt with the correct type:

• TR 600P and TR 750P with GX 160 engine: XPA 707
• TR 950P with GX 200 engine: XPA 707
• TR 950P with GX 270 engine: XPA 757
• TR 600E: XPA 782
• TR 950E: XPA 707

On the electric models, the tension is adjusted with a separate screw. The belt should be correctly tensioned, but not over-tightened, as this can cause damage in the long run.

If the blades do not rotate, or rotate too slowly, the troubleshooting section points to a broken V-belt or a slipping belt. On the petrol models, the cause can also be a broken clutch cable. The operating instructions for the petrol models also say that the rubber dampers should be checked regularly, and that damaged dampers should be replaced.

The blade arms and the pressure plate

The blade arms are cleaned and greased in five steps:

• Loosen the nuts and bolts on the blade arms
• Pull the blade arms out of the hub
• Clean the contact surfaces on the blade arms and the hub
• Grease the surfaces and reassemble the blade arms
• Grease the nipples until grease comes out around the blade arms

The specified grease is Shell Regina Grease 2 or equivalent. When the pressure plate is cleaned, check the bearing lubrication, using the same grease. Remove the blade spider, using a puller if it is stuck on the shaft, then clean the pressure plate, ball bearing, sliding sleeve and bearing plate and carefully grease them.

The gearbox is lubricated for life. If the oil does need changing, the recommended oil is synthetic Mobil SHC 634.

When the machine shakes or runs sluggishly

The troubleshooting section gives three causes of the power trowel shaking: one or more blades are bent or defective, one or more blades do not move on the hub, or the pressure plate is out of true. Replace damaged parts. If the blades do not move, remove them, clean the contact area and apply fresh grease to all contact areas.

If the spider rotates sluggishly on a petrol model, the cause may be a cold engine, too low an engine speed when the clutch engages, a float pan being used while the concrete is too fresh, or a defective engine or gearbox.

The electric models: cables and frequency converter

On TR 600E and TR 950E, the cables run inside the handle tubes. Check the cables regularly for damage or cracks, and also look over other electrical equipment. If the motor on the TR 950E does not start, one of the troubleshooting points is to check the light on the frequency converter: a flashing green light confirms that it is OK.

Lifting and storage

Remove the trowel pan before the machine is lifted or moved, lift only by the lifting eye, and do not use the guard ring for lifting. Clean the machine thoroughly before storage, and keep it in a dry place. If a petrol model is stored in the working position, the fuel tank should be no more than half full, otherwise fuel can escape from the vent hole in the tank cap.

Service and parts

The operating instructions say that damaged parts should be replaced immediately, that worn components should be replaced in good time, and that genuine parts should be used. Sigurd Stave Maskin AS is Kiwa-verified and certified to carry out annual inspections, and has mobile service technicians based in Oslo and Bergen. Workshop phone, daytime: +47 969 13 856.

If you are choosing a new machine, the guide Choosing a power trowel compares the pan sizes.