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Cooling — OBS Chevy/GMC Trucks

Pumps, thermostats, fan clutches & sensors — keep temps in check. OEM, GM & aftermarket part numbers for 1988–1998 Chevy/GMC C/K 1500 & 2500. Always verify fitment for your exact year, engine & drivetrain before ordering.

⚠️ Verify before buying. Fitment varies by year, engine (4.3/5.0/5.7/7.4), and 2WD/4WD. These are reference numbers — confirm against your VIN/build before ordering.
1Water Pump (Vortec, 1996-1998)Details →
🛠 Fits: 1996-1998 C/K 1500 & 2500 (5.0L & 5.7L Vortec)
New (not reman) water pump for 1996-1998 Vortec V8 trucks; includes gaskets
252-711ACDelco (OEM)
GM #: 88926225
📝 Vortec pumps differ from the earlier TBI short pump — don't cross the two. Kit ships with gaskets/seals.
2Water Pump (TBI, 1988-1995)verifyDetails →
🛠 Fits: 1988-1995 C/K 1500 & 2500 (4.3L, 5.0L, 5.7L)
Short-style small-block water pump for TBI-era gas engines
252-584ACDelco (OEM)
Aftermarket: GMB 130-1240
📝 Standard short-leg SBC pump. 7.4L big-block uses its own pump — verify by engine before ordering.
3Fan Clutch (Thermal)verifyDetails →
🛠 Fits: 1988-1998 C/K 1500 & 2500 (gasoline engines)
Thermal fan clutch for the mechanical cooling fan
15-4694ACDelco (OEM)
Aftermarket: Hayden 2747
📝 If the fan roars constantly or freewheels when hot, the clutch is done. Hayden 2747 is the popular severe-duty upgrade for towing.
4Radiator CapverifyDetails →
🛠 Fits: 1988-1998 C/K 1500 & 2500
Pressure cap for the radiator filler neck (15-16 psi)
RC27ACDelco (OEM)
Aftermarket: Stant 10230
📝 Cheap insurance — a tired cap causes overflow puking and low coolant mysteries.
5Engine Coolant Temperature SensorverifyDetails →
🛠 Fits: 1988-1998 C/K 1500 & 2500 (gasoline engines)
ECT sensor that feeds the computer (separate from the dash gauge sender)
213-928ACDelco (OEM)
📝 Two temp sensors on these trucks: this one talks to the PCM, a separate sender runs the gauge. Rough cold starts and rich running point here.

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