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Home >> GMC >> 1985 >> Forward Control 7.4 W, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Air Injection System >> Trouble Shooting >> Excessive Pump Noise

Excessive Pump Noise

Leak in hose or loose hose. Hose touching other engine parts. Diverter valve or by-pass valve failure. Check for valve failure, pump mounting loose, pump or impeller damaged.