1997 GMC Sonoma Owner's Manual - Page 363

I Long TripmighwayMaintenanceSchedule I (or every 60 months since last service, whichever occurs first). See "Engine Coolant" in the Index for what to use. Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test the cooling system and pressure cap. An Emissio~lContt-ol Ser\iw. 150,000 Miles (240 000 km) - Uses such as found in taxi, police or delivery service. I I 0 Drain, flush and refill cooling system whicle urlder C I I I J . ofthc~st~ cwrzclitinns,theJluid a r z c ! f j l t r r do not require c*i?trrzging. If'yorr do not use ~ Manual transmission fluid doesn't require change. 0Inspect Positive Crankcase Ventilation ( P c v ) valve. An Etnission Control Service. DATE ACTUAL MILEAGE SERVICED B Y DATE ACTUAL MILEAGE SERVICED BY: