How to Replace Water Pump on Ford Explorer


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Water pump is known as the heart of the automobile cooling system. It circulates coolant through the engine and the heater core. At the very basic, the water pump consists of an impeller, a driving shaft, pulley, bearing and seals. The water pump is driven by the power from the engine. Power is transmitted from the engine crankshaft to the water pump through the serpentine belt.

Signs of failure

  1. Coolant leaking across the pump seals
  2. Engine overheating
  3. Engine check light appears
  4. Very low coolant level
  5. Noisy pump bearings
  6. Damaged impeller

(Warning – the exact sizes of the tools may vary. Please consult an expert technician on tools, safety and procedures before performing the DIY)

Estimated time – 3 hours approximately

This article provides simple yet detailed DIY steps to replace the water pump on a Ford Explorer 4.0L.

Tools & Parts Required

  1. Flat blade screwdriver
  2. Fan clutch tool ( fan clutch wrench and fan hub wrench)
  3. Belt tensioner tool or 3/8” ratchet
  4. Metal or wood scrapper
  5. RTV silicone
  6. Catch pan
  7. Wrench set
  8. Ratchet and socket set
  9. Pliers
  10. Ford Explorer Water Pump (Buy at lowest price starting from $25)

Before starting the DIY, ensure that the engine is cold (turned off for the past 2 hours).

Draining the radiator fluid

  1. Place a catch pan under the radiator.
  2. Open the radiator drain valve and allow the coolant to drain out completely from the radiator. (Warning – Engine coolant consists of heavy metals like chromium, cadmium and lead. These metals are highly toxic and are potentially hazardous to man and animals as well, when disposed carelessly. Hence it is advised to properly dispose engine fluids if not recycling them)
  3. Close the drain valve after draining the radiator.

Clearing the obstructions

  1. In order to achieve maximum ease in removal, it’s mandatory to disconnect some of the hoses.
  2. Locate the air intake tube; this pipe has a significantly large diameter and is connected to the throttle body.
  3. Use a flat blade screwdriver to unscrew the screws that hold the clamps on the either end of the air intake tube. Now carefully disconnect the air intake tube.
  4. The bypass hose is to be removed next. Use pliers to release the tension on the clamps and then push the clamp backwards. Now you can remove the bypass hose.
  5. Next in the line is crankcase breather hose. It is a thin tube that connects the crankcase to the air intake tube. Disconnect this tube from the intake tube end.
  6. The last step in this section is to unplug the MAF (Mass Air Flow) sensor.

Cooling fan and fan shroud

  1. Undo the two bolts that hold the fan shroud at the top, and then the two clips at the bottom.
  2. Remove the fan and fan shroud at the same time. Pull the duo simultaneously in vertically upward direction. Be careful that you do not damage other engine parts while removing the assembly.
  3. Loosen the fan using the fan clutch tool, but do not remove it.
  4. Hold two bolts on the pulley using the fan clutch wrench. The fan clutch wrench is used to restrict the rotation of the pulley during the removal process. Rotate the clutch bolt in the clockwise direction using the open end fan hub wrench, while still holding the fan clutch wrench in its position.

Water pump pulley and serpentine/engine accessory belt

  1. A belt tensioner tool or a 3/8” ratchet fits in to the slot provided in the tensioner pulley.
  2. Rotating the ratchet/tool in the clockwise direction will release the tension on the serpentine belt. Using a pipe may provide additional ease in removal and leverage.
  3. Remove the belt from over the pulleys.
  4. Make sure that you have access to the ‘Belt Routing Diagram’ before removing it. The diagram can be accessed from engine compartment or the owner’s manual. You can also draw it roughly on a piece of paper as this will surely avoid mistakes during re installation.
  5. Thereafter the pulley can be removed by undoing the four bolts that hold it in its position.

Disconnecting the hoses and the water pump

  1. Disconnect the heater hose and the lower radiator hose from the water pump. Allow the fluid to drain out from the hoses before working further.
  2. Undo the 12 bolts that hold the water pump, and then remove the water pump carefully.

Comparing with the new one and pre installation procedure

  1. Compare the new pump to the old one before installing the new one.
  2. Use a scrapper or a wire brush to clean the mounting surface of the pump on the engine.
  3. Apply a thin and uniform coat of RTV silicone on the mounting surface of the new pump and on the timing cover too.
  4. Next install the gasket on the new pump.

Installing the new pump and filling new coolant

  1. After cleaning the mounting surface, applying RTV and installing a fresh gasket; fit the new pump.
  2. Fill a 50/50 mixture of fresh coolant and water in to the coolant bottle. You can also add water pump lube to the mixture. The lube lubricates the pump bearing.

Post installation checks

  1. After completing the installation process; check for leaks in the system. If everything seems alright, start the engine. Starting the engine will cause the coolant to flow through the system. Fresh coolant may then have to be added to balance the level in the system.
  2. Take the car for a short ride and keep an eye on the temperature gauge while driving. Also check for leaks and coolant levels after returning back.


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About John Marshall

John is an automotive enthusiast and a professional auto blogger, He contributes his expertise with a view of educating car owners about DIY repair tips and other car care awareness information along with some interesting car news. Follow John Marshall on Google Plus and find out latest updates related to automotive industry.