Choosing the Right Engine Water Pump for Your 1979-1987 GMC G1500
Keep your classic G-series van from overheating with a reliable new water pump.
- You must confirm if your van needs a 'long' (approx. 7") or 'short' style water pump before ordering; it is most likely the 'long' style.
- Symptoms of failure include coolant leaks from the weep hole, engine overheating, and grinding noises from the front of the engine.
- For a stock daily driver, a quality standard replacement from a brand like ACDelco, Gates, or GMB is a reliable and cost-effective choice.
- It is highly recommended to also replace the thermostat, belts, and coolant hoses at the same time.
Is Your Water Pump Failing?
A water pump on a 1979-1987 GMC G1500 will usually give clear signs before it fails completely. Ignoring these symptoms can lead to engine overheating and serious damage. Be aware of the following signs:
- Coolant Leaks: This is the most common symptom. You may find puddles of green or orange fluid under the front of your van. The leak often starts from a small "weep hole" on the bottom of the pump, which is designed to leak when the internal seal fails.
- Engine Overheating: If the temperature gauge on your dashboard is climbing higher than normal, the pump may not be circulating coolant effectively.
- Grinding or Whining Noises: A high-pitched whine or a rough grinding sound coming from the front of the engine that changes with engine speed points to a bad bearing inside the water pump.
- Wobbly Pulley: If you can see the water pump pulley wobbling while the engine is running, or can wiggle it by hand with the engine off, the internal bearings are worn out and complete failure is imminent.
Critical: Identify Your Pump Before Ordering
The most common mistake when ordering a water pump for a Small Block Chevy engine is choosing the wrong style. These engines use either a "long" or "short" style pump. For 1979-1987 GMC G1500 vans, you will most likely need the "long" style pump. However, you must verify what is on your vehicle before ordering.
- Long Pump: Measures approximately 7 inches from the engine block mounting surface to the fan pulley mounting flange. There will be a noticeable gap between the pump body and the timing chain cover.
- Short Pump: Measures about 5 5/8 inches.
Choosing the Right Aftermarket Water Pump
With an older vehicle like the G1500, a quality aftermarket part is often your best and only option. Here’s a breakdown of available brands to help you choose.
Tier 1: OEM-Quality & Heavy-Duty
These brands are known for reliability and are a safe bet for a daily driver or work van. They are designed to meet or exceed original factory specifications.
- ACDelco: Often the original parts supplier for GM, ACDelco is a trusted name. Their "Professional" line is a common aftermarket choice, though quality can vary. For peace of mind, it's a top choice.
- Gates: Known for their belts and cooling system components, Gates water pumps are widely considered a reliable OEM-equivalent replacement.
- Melling: A reputable brand in the engine parts world, Melling is another solid choice for a durable, long-lasting pump.
Tier 2: Performance & High-Flow
If your van is modified, used for heavy towing, or you simply want improved cooling, these brands offer high-flow aluminum pumps. They are lighter and designed to move more coolant than standard pumps.
- Edelbrock: A top name in performance parts, Edelbrock pumps are made in the USA and known for quality construction and improved cooling efficiency. They are a premium, more expensive option.
- Proform, PRW, Mr. Gasket, Frostbite: These brands also offer aluminum, high-flow designs that can help in demanding situations. They are often chosen for custom builds and street rods.
Tier 3: Standard Aftermarket
These brands offer a good balance of price and quality for a standard replacement. They are a popular choice for budget-conscious repairs.
- GMB: Often considered one of the better standard aftermarket brands, GMB pumps are a reliable and cost-effective choice for most owners.
- Dayco, US Motor Works: These are common, readily available aftermarket brands that provide a functional replacement for a stock vehicle.
Pro Tip: Replace More Than Just the Pump
Since you have to drain the coolant and remove the belts anyway, it's highly recommended to also replace the thermostat, radiator hoses, bypass hose, and V-belts at the same time. It's also the perfect time to inspect the fan clutch for wear.
Cost of Replacing a 1979-1987 GMC G1500 Water Pump
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Water Pump | $53 - $279 |
| Shop Labor | $250 - $400 |
| Total Estimated Cost | $303 - $679 |
Frequently Asked Questions (FAQ)
Were there any recalls for the G1500 water pump?
No. Searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls or technical service bulletins (TSBs) specifically for the engine water pump on the 1979-1987 GMC G1500. Any failures are due to age and normal wear.
Do I need a special water pump for V-belts?
Yes. Your 1979-1987 G1500 uses a V-belt system, which requires a standard rotation (clockwise) water pump. Counter-clockwise pumps are for later model vehicles with serpentine belts.
Do I need to use sealant on the gaskets or bolts?
While some gaskets have a self-sealing coating, it is good practice to use a thin layer of gasket sealant to hold them in place. More importantly, you must apply thread sealant to the threads of the water pump bolts, as they pass through into the engine's water jacket and can leak coolant if not sealed.
Do I need a high-flow water pump?
For a stock engine used for normal driving, a standard replacement pump from a quality brand like ACDelco, Gates, or GMB is perfectly fine. A high-flow pump is generally not necessary unless you have a high-performance engine or do a lot of heavy towing in a hot climate.
Technical Specifications
OEM Part Numbers: 19195150
Rotation: Standard (Clockwise) for V-belt systems. Style: Most likely 'Long' style (approx. 7" from block to hub flange).
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.