Governor Weight Retainer Ring Failures
Background information of failed governor weight retainer ring: diesel fuel that is contaminated with excessive
water or the presence of alcohols found in some additives not normally present in recommended diesel fuels may
accelerate failure of the Poly-urethane (Pellethane) governor weight retainer ring in the injection pump. Failure of the ring is heat related and will most likely result in a rough idle condition and, in some instances, the engine may not run. A failed ring will break apart into small black particles plugging the fuel return check valve. Remove the check valve if small particles are observed. Confirm the findings by removing the pump cover and rotating the governor weight retainer in both directions (Figure 4-82) using a suitable tool or screwdriver. If the retainer moves more than 1/16″ and does not return, the retainer ring has failed. Normally a failed ring will allow 1/4″ free movement.
If a failed ring is found, the pump will require removal from the engine. Follow the procedures listed in this manual for replacement.