Manual - Chapter 5 - Fuel & Oil

24: Oil pressure relief valve: general

  1. The oil pressure relief valve consists of a spring-loaded plunger which is fitted in a bore in the oil pump body.
  2. Depending on the tools available, it may be possible to remove the valve components with the oil pump installed, in which case it will be necessary only to drain the engine oil (see Maintenance - Minor Service - Change the engine oil and filter) and to drain the coolant and withdraw the radiator bottom hose (see Chapter 4 - Cooling - Draining.) before removing the valve. If not remove the oil pump from the machine. See Section 23.
  3. 3 Unscrew the valve plug and withdraw the spring and plunger. Check both for signs of wear or damage and renew them, if necessary; note that the spring should be renewed if there is the slightest doubt about its performance. Polish away any burrs or raised edges from the plunger and check that it is free to slide smoothly, but without play, in the pump body.
  4. On refitting, renew its sealing washer and tighten the valve plug to the specified torque wrench setting.

24.3a Unscrew pressure relief valve plug from pump body - note sealing washer ...

24.3b ... withdraw pressure relief valve spring ...

24.3c ... and plunger - check carefully for dirt or wear