Valvoline.com

Belt-Less Water Pump Replacement

Direct-drive coolant disperser R&R

The stereotypical water pump has a fan attached to its snout. The engine's accessory-belt system spins a pulley, which in turn rotates the pump's impeller to circulate coolant through the engine.

Another style of water pump doesn't use a belt to spin its impeller. This type uses the timing gear or other direct-drive system. In other words, the water pump has a shaft that's driven directly by the engine, similar to how power transfers from the engine to the transmission.

While both pump styles are effective at circulating coolant throughout the engine, each has its pros and cons. Obviously, belts have limited service lives, so it's only a matter of time until they fail. However, belts are usually fairly easy to access, diagnose and replace. Another plus: Belt-driven water pumps are also usually relatively easy to remove and replace.

Belt-less pumps have fewer parts (no pulley or belt), so they theoretically last longer. The drawback is that these water pumps can be obscured, causing the average do-it-yourselfer to curse the automotive engineer who obviously never had to service his or her design. Replacing these pumps is generally more time-consuming than with belt-driven ones: Numerous other components and system may have to be removed to gain access to the pump.

Pump Problems

In general, one of two things usually causes water-pump failure. The first is when the pump's shaft's bearings wear out. Squealing and whining usually foreshadow the bearings' ultimate demise. The other scenario is seal failure. This causes coolant to leak from the pump's "weep" hole. Coolant drips that can't be traced to the radiator hoses, overflow tanks or the thermostat housing often originate at the water pump's gaskets.

The how-to images shown here are on a late-'80s GM N-car (Skylark, Somerset, Achieva, Calais, Grand Am) with the 2.3-liter Quad-4 engine. This engine is infamous for the overall inaccessibility of its serviceable components. As such, this particular job might fall toward the worst-case-scenario side of the overall water-pump-replacement spectrum. Hopefully your pump is more accessible.

Installation Tips

> Wait until the engine is completely cool before beginning the project.

> Disconnect the battery's negative cable to keep electric fans from coming on at inopportune times.

> Open the radiator's petcock and drain the coolant into a large pan.

> If the coolant was recently replaced, cover the drained fluid and funnel it back into the system later.

> If the coolant is old or dirty, dispose of it at an approved toxic-waste facility.

> Always keep coolant covered or in a sealed container so that kids and pets won't drink it and poison themselves.

> Dilute antifreeze with distilled water to minimize cooling-system corrosion and maximize water-pump longevity.

> Some vehicles may need to be raised and secured on jackstands in order to drain the radiator and/or access the water pump.

> Refer to a factory service manual for specific procedures, including other components that need to be removed, fastener tightening sequence and proper fastener torque.