Manual - Chapter 4 - Cooling

5. Radiator: Removal, cleaning and examination

  1. Drain the radiator as described in Section 2 - Cooling system: draining. Remove the air intake hose.
  2. Disconnect and remove the top, bottom, filler and bypass hoses from the radiator. Remove the radiator top mounting bolt or nut, withdrawing the insulating material (where fitted) to reach it.
  3. Tilt the radiator forwards, disconnect the fan motor lead at its connector and withdraw the radiator.
  4. Inspect the radiator mounting rubbers for perishing or compaction. Renew the rubbers if there is any doubt as to their condition. The radiator may suffer from the effect of vibration if the isolating characteristics of the rubber are reduced
  5. Remove any obstructions from the exterior of the radiator core, using an air line. The conglomeration of moths, flies, and road dust usually collected in the radiator matrix severely reduces the cooling efficiency of the radiator.
  6. The interior of the radiator can most easily be cleaned while the radiator is on the motorcycle, using the flushing procedure described in Section 3 - Cooling system: flushing. Additional flushing can be carried out by placing a hose in the filler neck and allowing the water to flow through for about ten minutes. Under no circumstances should the hose be connected to the filler neck mechanically as any sudden blockage in the radiator outlet would subject the radiator to the full pressure of the mains supply (about 50 psi). The radiator should not be tested to greater than 17 psi.
  7. Bent fins can be straightened, if care is exercised, using two screwdrivers. Badly damaged fins cannot be repaired; a new radiator will have to be fitted if bent fins obstruct the air flow more than about 20%.
  8. Generally, if the radiator is found to be leaking, repair is impracticable and a new component must be fitted. Very small leaks may sometimes be stopped by the addition of a special sealing agent in the coolant. If an agent of this type is used, follow the manufacturers instructions very carefully. Soldering, using soft solder, may be effective for caulking large leaks but this is a specialist repair best left to experts.
  9. Refitting is a reversal of the removal procedure. Ensure that the radiator is settled securely on its mountings before tightening the mounting bolt and that the electrical lead and all hoses are correctly secured.


5.2a Disconnect radiator filler and top hoses...


5.2b ...followed by bypass and bottom hoses...


5.2c ...then release radiator top mounting bolt or nut


5.3a Tilt radiator forwards on bottom mountings...


5.3b ...until fan motor lead can be disconnected


5.9 Check all hose clamps are tight on refitting