Kawasaki Z400 - Service manual > 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 with the motorcycle held perpendicular (Do not use the sidestand.).

If the coolant level is lower than the  "L"  level line [A], unscrew the reserve tank cap and add coolant to the 'F level line [B].

"L": low

"F": full

NOTICE

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 reserve 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.

Cooling System Inspection

Water Hose and Pipe Inspection (coolant leak, damage, installation condition)

The high pressure inside the radiator hose can cause coolant to leak [A] or the hose to burst if the line is not properly maintained.

• Visually inspect the hoses for signs of deterioration.

  Squeeze the hoses. A hose should not be hard and brittle, nor should it be soft or swollen.

Replace the hose if any fraying, cracks [B] or bulges [C] are noticed.

• Check that the hoses  are securely connected.

Coolant Change

WARNING

Coolant can be extremely hot and cause severe burns, is toxic and very slippery. Do not remove the radiator cap or attempt to change the coolant when the engine is hot; allow it cool completely.

Immediately wipe any spilled coolant from tires, frame, engine or other painted parts. Do not ingest coolant.

• Remove:

Right Middle Fairing (see Middle Fairing Removal in the Frame chapter) Coolant Reserve Tank (see Coolant Reserve Tank Removal in the Cooling System chapter)  Radiator Cap [A]

• Place a container under the coolant drain bolt [A], then remove the drain bolt.

• The coolant will drain from the radiator and engine.

• Replace the drain bolt gasket with a new one.
• Tighten the drain bolt with the gasket.

Torque -Coolant Drain Bolt: 7.0 N-m (0.71 kgf-m, 62 in-lb)

• When filling the coolant, choose a suitable mixture ratio  by referring to the coolant manufacturer's directions.

NOTICE

Soft or distilled water must be used with the antifreeze in the cooling system.

If hard water is used in the system, it causes scales accumulation in the water passages, and considerably reduces the efficiency of the cooling system.

Water and Coolant Mixture Ratio (Recommended) Soft Water: 50% Coolant: 50% Freezing Point: -35% (-31ºF) Total Amount: 1 .3 L (1.4 US qt)

• Fill the radiator up to the filler neck [A] with coolant.

NOTE

• Pour in the coolant slowly so that it can expel the air from the engine and radiator.

• Check the cooling system for leaks.
• Tap the radiator hoses to force any air bubbles caught inside.
• Fill the radiator up to the filler neck with coolant.
• Install the coolant reserve tank (see Coolant Reserve Tank Installation in the Cooling System chapter).
• Fill the reserve tank up to the "F" (full) level line [A] with coolant and install the cap [B].
• Install the radiator cap.
• Start the engine, warm it up thoroughly until the radiator fan turns on and then stop the engine.
• Check the coolant level in the reserve tank after the engine cools down.

NOTICE

Do not add more coolant above the "F" level line.

Water How and O-ring Replacement

• Drain the coolant (see Coolant Change).
• Remove:

Thermostat Housing (see Thermostat Housing Removal in the Cooling System chapter) Water Pump Cover (see Water Pump Cover Removal in the Wing System chapter) Water Hoses [A]

• Apply grease to the new O-rings [B] and install them.

  Run the new hoses according to the Cable, Wire, and Hose Routing section in the Appendix chapter).

• Install the removed parts (see appropriate chapters).
• Fill the coolant (see Coolant Change).
• Check the cooling system for leaks.

See also: