Zetor 7745 service schedule

1. Stop the engine and take the key out.
2. Take off the radiator grille and release the three clips that hold the dust bowl to the air cleaner body.
3. Tip out the old oil and dirt and clean the bowl.
4. Pull the baffle plate and lower element out of the body with the two handles. Separate them and wash the lower element in diesel or paraffin. Do not use petrol, water, benzene, alcohol or other solvents.
5. Refit the element in the baffle plate and put it back in the body without squashing it.
6. Fill the bowl with fresh engine oil to the level mark. In frost the oil may be thinned with up to 30% diesel; change it once the weather warms up.
7. Refit the bowl and close the three clips.

Tools: Drain tray, Diesel or paraffin for washing, Rags

1. Stop the engine and take the key out.
2. Press the belt midway on its longest run. It should not deflect more than 15 mm.
3. To adjust, slacken the alternator mountings, move it to set the tension and retighten.

Tools: Spanners, Rule

1. Lower implements, stop the engine, take the key out and chock the wheels.
2. Every 100 h, grease: front axle carrier pin, wheel track extensions, clutch release shaft, lower link sway limiter nuts and the front PTO shaft cross joints (where fitted).
3. Every 100 h, oil: about 10 drops on the clutch release bush, plus a few drops on the handbrake Bowden cable, the manual PTO clutch release and the pick-up hitch.
4. Every 400 h, also grease: the power steering cylinder head (2 points), the steering linkage heads (4 points) and the draft control yoke.
5. Every 600 h, also grease: cab door hinges, steering column bearing and the three-point linkage pins.

Tools: Grease gun, Oil can, Rags

1. Run the engine to working temperature, then park level, lower implements, stop the engine, take the key out and chock the wheels.
2. Remove the drain plug from the bottom of the engine sump and let the warm oil drain. Clean any metal particles off the plug and refit it.
3. Centrifugal filter: undo the bolt, lift off the cover and take out the rotor. Undo the M 32 nut and separate the two halves.
4. Wash both halves carefully in petrol or diesel, let them dry and put them back together with the alignment marks on the two halves facing each other. If the marks don't line up the rotor runs out of balance.
5. Refit the rotor and cover.
6. Pour in the specified quantity of oil through the filler.
7. Start the engine and run it for 2–3 minutes at 750–800 rpm, then stop it. Let the oil settle and top up to the upper dipstick mark.
8. Check the oil pressure warning lamp goes out after starting, and look for leaks.

Tools: Drain tray (15 L), Spanners, Socket for the M 32 rotor nut, Petrol or diesel for washing, Funnel, Rags, Gloves

1. Stop the engine and take the key out. Keep naked flames away.
2. Turn off the fuel supply and remove the coarse filter bowl.
3. Empty out any water and sediment, and wash the bowl and strainer in clean diesel.
4. Refit with the sealing ring seated properly, turn the fuel back on and bleed the system (see the fine fuel filter task).

Tools: Spanners, Clean diesel, Small container, Rags

1. Lower implements, stop the engine, take the key out and chock the wheels.
2. Undo the nut on the hydraulic pump bottom cover, under the gearbox.
3. Pull the nut with the magnet and the strainer downwards.
4. Take the strainer off the magnet and wash it in clean diesel. Wipe the dirt off the magnet.
5. Reassemble in reverse order and top up the gearbox oil to the dipstick mark.

Tools: Spanners, Small drain tray, Clean diesel, Rags

1. Stop the engine, take the key out and chock the wheels. Keep naked flames away.
2. Turn off the fuel, remove the fine filter housings and throw away the old elements and seals.
3. Clean the housings, fit new elements and new seals, and refit.
4. Turn the fuel back on. Pressurise the system with a few strokes of the hand primer, slacken bleed screw 1 and let the froth out, then tighten. Repeat until clean fuel comes out.
5. Do the same at bleed screw 2.
6. Start the engine and check for leaks.

Tools: Spanners, Clean diesel, Container, Rags

1. Lower implements, stop the engine, take the key out and chock the wheels.
2. Clean around the filter housing on the right of the engine.
3. Open the housing, take out the old paper element and throw it away.
4. Fit the new element with a new seal and close the housing.
5. Start the engine, work the lift a few times and top up the gearbox oil to the dipstick mark.

Tools: Spanners, Small drain tray, Rags

1. Stop the engine, take the key out and let it go fully cold.
2. Remove the rocker cover.
3. Turn the engine until the piston of the cylinder being checked is at top dead centre on compression (both its valves closed). Firing order is 1-3-4-2.
4. Set inlet and exhaust to 0.25 ± 0.05 mm: slacken the locknut, turn the screw until the feeler is a light drag, and lock it.
5. Do each cylinder in firing order, then refit the cover.

Tools: Feeler gauges, Ring spanner and screwdriver, Means to turn the engine

1. This needs an injector tester; a workshop can do it.
2. Test each injector, on the engine or removed, and set the opening pressure at the top of the range (18.6 MPa).
3. If an injector is removed, clean its seat in the cylinder head. Grease the injector body with LITOL 24 before refitting and keep it in its correct position.

Tools: Injector tester (Motorpal NC 50 or NC 251 type), Spanners, LITOL 24 grease for refitting

1. Park level, stop the engine and take the key out. Jack up the rear so both rear wheels turn freely, and support on stands.
2. Remove the cover from the brake cylinder.
3. Tighten the self-locking adjusting nut on one side until the wheel can't be turned by hand, then slacken it by one turn. Repeat on the other side.
4. If the rod end sticks out of the adjusting nut by 10 mm, or braking stays weak, the brake discs need renewing.
5. Check the handbrake: with the lever off, its adjusting nut must just touch the lever pin.
6. Push rod free play at the master cylinders is 0.5–1 mm (3.5–6 mm at the pedal). With the pedals latched, road test and even up the two sides at the adjusting nut, but by no more than one turn.

Tools: Jack and axle stands, Chocks, Spanners, Rule

1. Park on level ground with the wheels straight ahead.
2. Measure between the front tyres at hub height, front and rear.
3. Compare with your handbook's figure and direction. If it needs adjusting, set the track rod and lock its nuts.

Tools: Toe gauge or tape measure, Spanners

1. Work the tractor so the oil is warm, park level, lower the linkage, stop the engine, take the key out and chock the wheels.
2. Remove the gearbox drain plug and the final drive housing drain plug and let all the oil drain.
3. Clean the suction strainer and magnet (see that task) and change the fine filter element.
4. Refit the drain plugs.
5. Fill through the filler on the gearbox cover. The filler cap is also the dipstick; check it screwed fully home.
6. Fill to the middle mark for normal work, or the upper mark on slopes or with external rams.
7. Run the engine, work the lift and any rams, then recheck the level.

Tools: Large drain tray (40 L), Spanners, Funnel or pump, Clean diesel, Rags

1. Stop the engine, take the key out and chock the wheels.
2. Steering box: remove the drain plug at the bottom of the box, drain, refit and fill to the top of the filler neck.
3. Power steering: drain the reservoir through the plug at its base. Keep everything very clean.
4. Change the filter element in the reservoir and refill with fresh oil.
5. Start the engine and turn the wheel lock to lock a few times, then top up the reservoir.

Tools: Drain trays, Spanners, Funnel, Lint-free rags

1. Park level, stop the engine, take the key out and chock the wheels.
2. Drain the front axle centre housing and each wheel reduction hub, turning the hubs so the plugs are at the bottom.
3. Refit the drain plugs and refill each housing to its level plug.
4. Renew the lubricant in the double joints as the handbook describes.
5. Check for leaks after a short drive.

Tools: Drain tray, Spanners, Pump or funnel

1. Fill the reservoir with fresh fluid. Keep everything absolutely clean.
2. Fit a rubber tube to the bleed screw with its end under fluid in a clear jar held high.
3. With the pedals unlatched, open the bleed screw no more than 1/4 turn, press the pedal, close the screw, then let the pedal up.
4. Repeat until no bubbles come out and the old fluid is flushed through. Do each brake separately and never let the reservoir run low.
5. Bleed the clutch release cylinder the same way at its bleed screw.
6. Top up to between half and three-quarters full.

Tools: Bleed tube, Clear jar, Spanner for bleed screws, A helper

1. Work only on a cold engine.
2. Open the drain tap at the bottom left of the radiator and the drain tap on the engine block.
3. Flush through with clean water, then close the taps.
4. Refill with the antifreeze and demineralised water mix.
5. Run the engine to warm up, let it cool and top up.

Tools: Drain tray, Antifreeze tester