DS900X Coolant Change & Cooling System Bleed

The DS900X cooling system has a radiator with a pressure cap, a sub tank (expansion tank) and a thermostat that starts to open at 83 to 87 °C. The manuals give different coolant specifications, capacities, replacement intervals, drain bolt torques and bleed methods. Each value is listed below with its source.

Specifications at a glance

Where the manuals give different values, each value is listed with its sources and the row is marked Sources differ. We cannot verify which value is correct.

The engine workshop manual warns that coolant with silicate anti-corrosion additives can wear the water pump seal ring and block the radiator passages Engine manual p. 31. The owner's manual does not allow mixing coolants of different brands or specifications Owner's manual p. 78.

Do not use tap water. The engine workshop manual says running water may damage the engine, and the owner's manual does not allow filling with running water.

What you need

• Coolant to the specification you choose from the table. With concentrate, 1 L of concentrate and 1 L of distilled water make 2 L of 1:1 mix. With a pre-mixed product, buy at least 2 L.
• One new flat washer for the coolant drain bolt
• A socket that fits the drain bolt (M5). The manuals do not give the head size.
• Tools to remove the right windshield decorative component of the fuel tank. The chassis workshop manual also removes more parts (see step 1).
• Drain pan (3 L+ capacity)
• Funnel
• Paper towels and rags
• Coolant disposal container

Safety check before starting

The engine and radiator must be completely cold. The engine workshop manual warns that the coolant may spray out and injure you if the radiator cap is removed too early. The owner's manual gives the same warning for opening the cap after the engine has run. If any part of the cooling system feels warm, wait.

Procedure

The steps below follow the engine workshop manual p. 35-36, with the differences in the chassis workshop manual p. 29-30 and the owner's manuals noted.

1. Park and prep

Park on level ground on the centre stand (technique guide). Engine cold.

Remove the right windshield decorative component of the fuel tank.

The chassis workshop manual lists more parts to remove before draining: the air intake tube on the right of the air filter, the right bumper bar, the decorative cover for the muffler and the decorative cover for the right windshield plate.

2. Remove the radiator cap

Remove the radiator cap. Open it slowly. If you hear pressure releasing, stop and let the system cool further.

Set the cap aside on a clean rag.

3. Drain via the coolant drain bolt

The engine workshop manual calls it the water drainage bolt for the water pump, fitted with a flat washer. The chassis workshop manual places the coolant drain bolt on the left front of the engine. Place the drain pan beneath it.

Remove the bolt and the flat washer and let the coolant drain until it stops.

Fit a new flat washer and refit the drain bolt. Torque it to 6 N·m (engine workshop manual) or 4.5 N·m (chassis workshop manual). We cannot verify which is correct. The chassis workshop manual also says to clean the washer seat before refitting and to wipe spilled coolant off the muffler and engine.

4. Drain the sub tank (storage tank)

The sub tank holds 0.38 L. To empty it:

• Disconnect the siphon hose from the radiator.
• Pull the siphon hose off its clamp.
• Lead the hose end down below the engine and drain the coolant from the storage tank into the pan.
• Wash the inside of the storage tank with water.
• Fit the hose back into its clamp and onto the radiator.

5. Mix the new coolant (if using concentrate)

Mix 1 L of concentrate with 1 L of distilled water (1:1) in a clean container.

If your product is already pre-mixed, skip this step.

6. Refill via the radiator filler neck

Using a funnel, fill coolant through the filler port up to the neck of the cooling system.

7. Bleed the system

Air in the cooling system is one of the causes of high engine temperature listed in the engine workshop manual p. 32. The manuals describe different bleed methods. We cannot verify which is correct.

Engine workshop manual Engine manual p. 36, with the radiator cap off:

1. Shift to neutral.
2. Start the engine and let it idle for 2 to 3 minutes.
3. Open and close the throttle 3 to 4 times to expel the air.
4. Stop the engine and top up with coolant if needed.
5. Fit the radiator cap.

Chassis workshop manual Chassis manual p. 30: start the engine and let it idle with the filler port open. The level in the port may fall. Keep filling until the level stops falling, then fit the filler cap.

Owner's manual Owner's manual p. 78 Swedish owner's manual p. 93, with the radiator cap fitted: fill the radiator and fit the cap. Run the engine for 30 seconds, stop it and let it cool. Open the cap, top up if the level has fallen and refit the cap. Repeat until the level no longer falls. The English owner's manual adds that you pinch the water tube while filling to push out air, and that two or more rounds may be needed.

8. Fill the sub tank

Fill the sub tank (expansion tank) so the level is between the UPPER and LOWER marks Owner's manual p. 77. Do not fill above UPPER: the coolant expands when hot and can overflow from the tube. Refit the rubber cap of the sub tank.

9. Check for leaks and recheck the level

The chassis workshop manual says to start the engine after the replacement and run it at higher speed to check the coolant pipes for leaks.

Check the sub tank level with the engine cold and the bike upright. If you often need to add coolant, the owner's manual says there is a fault in the cooling system and to contact a VOGE dealer.

10. Reassemble

Refit the right windshield decorative component. If you followed the chassis workshop manual, also refit the air intake tube, the decorative covers and the right bumper bar.

11. Reset the service indicator

If the coolant change was part of a scheduled service, clear the maintenance indicator. See the DS900X service indicator reset guide.

12. Disposal

Dispose of the old coolant in an environmentally friendly way Owner's manual p. 79. Pour it into a sealed container and take it to a hazardous waste drop-off. Never pour coolant down a drain or onto the ground.

Common pitfalls

• Skipping the bleed. Air in the system is a listed cause of high engine temperature.
• Tap water dilution. The manuals do not allow running water (see above).
• Wrong or mixed coolant. Avoid coolant with silicate additives and do not mix brands or specifications.
• Reusing the drain bolt washer. The manuals say to replace it.
• Over-tightening the drain bolt. It is an M5 bolt. Use a torque wrench and the value you have chosen from the table.
• Forgetting the sub tank. The radiator level alone does not show the sub tank level. Check that it is between UPPER and LOWER.

Thermostat

The engine workshop manual tests the thermostat in hot water and says to replace it if it does not open at the given temperature Engine manual p. 36-38.

Sources

• Voge DS900X Engine Service Manual (English)
• Voge DS900X Chassis Service Manual (English)
• Voge DS900X Owner's Manual (English)
• Voge DS900X Owner's Manual (Swedish)
• Voge DS900X service schedule (Hungarian) p. 1

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