Bearing Driver Set: 57001–1129

4-8 COOLING SYSTEM

Coolant

Coolant• Deterioration Inspection

•Remove the left side cover (see Frame chapter). Visually inspect the coolant [A] in the reserve tank.

If whitish cotton-like wafts are observed, aluminum parts in the cooling system are corroded. If the coolant is brown, iron or steel parts are rusting. In either case, flush the cooling system.

If the coolant gives off an abnormal smell, check for a cooling system leak. It may be caused by exhaust gas leaking into the cooling system.

Coolant Level Inspection

NOTE

○Check the level when the engine is cold (room or ambient temperature).

•Check the coolant level in the reserve tank [A] with the motorcycle held perpendicular (Do not use the sidestand). If the coolant level is lower than the “L” level line [B], unscrew the reserve tank cap and add coolant to the “F” level line [C].

“L”: low ”F”: full

CAUTION

For refilling, add the specified mixture of coolant and soft water. Adding water alone dilutes the coolant and degrades its anticorrosion properties. The diluted coolant can attack the aluminum engine parts. In an emergency, soft water alone can be added. But the diluted coolant must be returned to the correct mixture ratio within a few days.

If coolant must be added often or the reservoir tank has run completely dry, there is probably leakage in the cooling system. Check the system for leaks.

Coolant ruins painted surfaces. Immediately wash away any coolant that spills on the frame, engine, wheels or other painted parts.

Coolant• Draining

Refer to the Cooling System in the Periodic Maintenance chapter.

Coolant• Filling

Refer to the Cooling System in the Periodic Maintenance chapter.

COOLING SYSTEM 4-9

Coolant

Pressure• Testing

•Remove the fuel tank (see Fuel System (DFI) chapter). Remove the radiator cap, and install a cooling system pressure tester [A] on the filler neck [B].

NOTE

○Wet the cap sealing surfaces with water or coolant to

•Build up pressure in the system carefully until the pressure reaches 123 kPa (1.25 kgf/cm², 17.8 psi).prevent pressure leaks.

CAUTION

During pressure testing, do not exceed the pressure for which the system is designed. The maximum pressure is 123 kPa (1.25 kgf/cm², 17.8 psi).

•Watch the gauge for at least 6 seconds.

If the pressure holds steady, the system is all right.

If the pressure drops and no external source is found, check for internal leaks. Droplets in the engine oil indicate internal leakage. Check the cylinder head gasket and the

•water pump.

Remove the pressure tester, replenish the coolant, and install the radiator cap.

Cooling System Flushing

Over a period of time, the cooling system accumulates rust, scale, and lime in the water jacket and radiator. When this accumulation is suspected or observed, flush the cooling system. If this accumulation is not removed, it will clog up the water passage and considerable reduce the efficiency• of the cooling system.

Drain the cooling system (see Cooling System in the Pe-

•riodic Maintenance chapter).

Fill the cooling system with fresh water mixed with a flushing compound.

CAUTION

Do not use a flushing compound which is harmful to the aluminum engine and radiator. Carefully follow the instructions supplied by the manufacturer of the cleaning product.

•Warm up the engine, and run it at normal operating tem-

•perature for about ten minutes.

•Stop the engine, and drain the cooling system.

•Fill the system with fresh water.

•Warm up the engine and drain the system.

•Repeat the previous two steps once more.

Fill the system with a permanent type coolant and bleed the air from the system (see Cooling System in the Periodic Maintenance chapter).

Coolant• Reserve Tank Removal/Installation

The coolant reserve tank is removed and installed during coolant change (see Cooling System in the Periodic Maintenance chapter).

4-10 COOLING SYSTEM

Water Pump

Water• Pump Removal

Refer to the Oil Pump Removal in the Engine Lubrication System chapter.

Water• Pump Installation

Refer to the Oil Pump Installation in the Engine Lubrication System chapter.

Water• Pump Inspection

Check the drainage outlet passage [A] at the bottom of the water pump body for coolant leaks.

If the mechanical seal is damaged, the coolant leaks through the seal and drains through the passage. Replace the mechanical seal unit.

Water• Pump Impeller Disassembly/Assembly

The sealing seat and rubber seal may be removed easily

•by hand.

Apply coolant around the surfaces of the rubber seal and

•sealing seat.

Install the rubber seal [A] and sealing seat [B] into the impeller by pressing them by hand until the seat stops at

•the bottom of the hole.

Tighten the water pump impeller bolt by special torque.

Torque - Water Pump Impeller Bolt: 9.8 N·m (1.0 kgf·m, 87 in·lb)

Water• Pump Impeller Inspection

Visually inspect the water pump impeller [A].

If the surface is corroded or if the blades are damaged, replace the impeller.

Water Pump Housing Disassembly

CAUTION

Do not damage the hole wall of the water pump housing.

•Insert a bar [A] into the pump housing [B], and hammer evenly around the circumference of the mechanical seal bottom [C].