Replacing the Water Pump

Procedure Length:

This procedure requires about 4-6 hours and can be performed alone. It was done on a 1992 Sentra SE-R, and likely applies to all North American versions of the SR20DE produced since the 1991 model year. If in doubt, check with your dealer and the factory service manual.

Tools and supplies:

• anti-freeze;
• distilled water;
• power steering fluid;
• jackstands;
• hydraulic floor jack;
• scissor jack;
• wood panel (mine was about a foot square);
• wrenches in 10mm, 12mm, and 14mm sizes (two 10mm wrenches is suggested);
• ratchets in 1/2", 3/8", and 1/4" drives;
• drive converters;
• sockets in 10mm, 12mm, 14mm, and 15mm sizes (standard and deep well for added reach);
• extensions in various sizes;
• torque wrench (good luck on making it fit);
• small and large Phillips screwdrivers;
• hammer or mini-sledge;
• wood stick (a 2" piece of broom handle);
• large pliers;
• needle-nose pliers;
• flexible scraper;
• siphon or vacuum pump;
• two large drain pans;
• funnel;
• brake cleaner or equivalent non-residual solvent;
• kitchen plastic wrap;
• empty plastic jug;
• flashlight

View the photos before beginning!

• Allow the car to cool for a few hours or overnight.
• Move the car outside if you plan to flush the cooling system. Otherwise, be prepared to catch a lot of water in some large drain pans.
• Move the heater control to full hot.
• Place a floor jack under the lower engine support, lift the car, then lower the car onto jackstands.
• Remove the right front tire.
• Remove both right splash shields using a ratchet, 10mm socket, and Phillips screwdriver.
• Place a large pan under the radiator drain plug.
• Remove the radiator cap, then remove the rear bleeder cap and radiator drain plug using a Phillips screwdriver. Coolant will drain.
• Remove the front bleeder plug using a ratchet, extension, and 10mm socket.
• Remove the engine block plug using a ratchet, extension, and 14mm socket. More coolant will drain.
• If desired, flush the cooling system at this time, following the appropriate steps in my Coolant Change Procedure without refilling.
• After all coolant has drained, install the radiator drain plug.
• Apply Loctite PST sealant to the engine block plug and install it.
• Remove and drain the coolant reservoir.
• Move the drain pan out from beneath the car.
• Loosen the alternator adjustment bolts using a ratchet and 12mm socket.
• Move the alternator downward by forcing it with a wood stick, perhaps assisted by a hammer.
• Remove the front accessory belt. This requires some wiggling and tugging.
• From above, place two 10mm wrenches in parallel on two bolts of the water pump pulley. Squeeze them together to loosen the left bolt. Force the pulley clockwise 90 degrees using one wrench and repeat with another pair of bolts. The first bolt will be re-tightened using this method, but will be easier to loosen using a single wrench. If you can't loosen the last bolt, rotate the pulley until the bolt is in the the 3-o'clock position, place the wrench vertically on the bolt, slide a deep-well socket with a long extension over the wrench, and tap with a hammer. Remove all bolts and the pulley.
• Remove the stop clip from the power steering pump adjustment bolt using needle-nose pliers.
• Loosen the power steering pump adjustment bolts using a ratchet and 12mm socket.
• Move the power steering pump forward by forcing it with a wood stick, perhaps assisted by a hammer.
• Remove the rear accessory belt. This requires some wiggling and tugging.
• Cover the crankshaft pulleys with kitchen plastic wrap.
• Place another drain pain beneath the pulleys to catch any power steering fluid that may drip.
• Remove the cap from the power steering reservoir and siphon all fluid into an empty jug.
• Disconnect the hose from the front end of the power steering cooler using a Phillips screwdriver.
• Disconnect the hose from the rear of the power steering reservoir using a Phillips screwdriver.
• Remove the bolts securing the power steering reservoir and related air conditioning hose bracket using a 10mm wrench, and remove the power steering reservoir.
• Move the drain pan out from beneath the car.
• Place the wood panel atop the scissor jack and raise the jack so it supports the engine across the full area of the oil pan.
• Remove the coolant reservoir seat using a ratchet, extension, and 10mm socket.
• Remove the right motor mount insulator pivot bolt using a ratchet and 14mm socket.
• Re-check the jack supporting the engine. Slowly remove the three engine attachment bolts and remove the mount using a ratchet, extension, U-joint (for center bolt), and 14mm socket.
• Slowly jack up the engine about two inches.
• Loosen and remove the bolts from the water pump in small increments using a ratchet and 10mm socket. The size of ratchet, length of socket, and any extensions used will depend on your angle of attack and whether you work from above or below.
• Tap the top of the water pump with wood stick and hammer until the gasket separates, then remove the water pump.
• Examine the water pump for interior corrosion, bearing play, and deposits around the weep holes. You'll discover how badly (or not) you needed to do this job.

Siesta time! Go eat lunch and drink your favorite beverage.

• Remove remaining gasket material from the engine mating surface using a flexible scraper and brake cleaner. The forward surfaces will be difficult to see. Be sure to remove any gasket pieces that fall into the pumping chamber, and wipe off excess cleaner.
• Arrange all pump bolts be prepare to install the pump now.
• Apply a 3mm bead of gasket maker around the mating surface of the water pump, surrounding the bolt holes too.
• Carefully mate the water pump to the engine and hold it there and insert some of the bolts by hand. Twist them until finger tight, using a socket if necessary.
• Tighten the bolts in small increments with a ratchet and 10mm socket until 'forearm tight', or about 15 ft-lbs with a torque wrench.
• Install the water pump pulley with all bolts and twist them until finger tight.
• Install the right motor mount only with the pivot bolt, but do not tighten.
• If necessary to align the holes for the attachment bolts, slightly lift the engine at a point on the air conditioning compressor bracket using the floor jack.
• Install the three attachment bolts and tighten to 40 ft-lb. Tighten the pivot bolt to 40 ft-lb.
• Move the scissor jack out from beneath the car.
• Remove the plastic wrap from the crankshaft pulleys.
• Install the rear accessory belt, then the front accessory belt.
• Tighten the alternator and power steering pump adjustment bolts with 12mm tools until each belt gives only a fraction of an inch under finger pressure, then tighten the stop bolts.
• Install the stop clip on the power steering pump adjustment bolt with needle-nose pliers (tricky).
• Tighten each bolt on the water pump pulley with a 10mm wrench till 'wrist tight', or about 5 ft-lbs with a torque wrench. The pulley will slip some in the belt, but you will succeed with diligence. If you can't tighten the last bolt, rotate the pulley until the bolt is in the the 9-o'clock position, place the wrench vertically on the bolt, slide a deep-well socket with a long extension over the wrench, and tap with a hammer. You may use this method to give each bolt a final tap.
• Install the power steering cooler and reservoir with a 10mm wrench and Phillips screwdriver.
• Install the coolant reservoir seat and coolant reservoir.
• Install the splash guards a 10mm wrench and Phillips screwdriver.
• Install the right front tire and lower the car off the jackstands.

At this point, I stopped until the next day. The gasket maker dries in one hour, but fully cures in 24 hours. You may also want to wait until the next day if you're concerned about obtaining a good seal, especially if assembly was done in cold weather.

The following section outlines quick refill methods for both the cooling and power steering systems. Optimum results in the cooling system are allegedly achieved by strictly following the factory service manual, but the method here has given me excellent results. The method here for replacing power steering fluid is similar to that in the service manual, but you may opt for a vacuum pump method found here.

• Fill the power steering reservoir with proper fluid.
• With the front and rear bleeders still open and the heater control to full hot, fill the radiator and coolant reservoir with a mix of your favorite anti-freeze and distilled water (between 50/50 and 70/30 anti-freeze to distilled water is typical) until some spills from the front bleeder.
• Install the front bleeder plug.
• Fill the radiator with more coolant until some spills from the rear bleeder.
• Install the rear bleeder cap and radiator cap.
• Start the engine. Listen for belt squeals and other strange noises, check for leaks, and keep an eye on the temperature gauge to avoid overheating.
• As the engine warms, take this opportunity to burp the power steering system. Turn the steering wheel lock-to-lock several times, adding fluid to the reservoir as air is purged until the level settles into the indicated range on the dipstick.
• After the radiator fan begins to run, allow the engine to run a few more minutes, then shut down.
• Allow the engine to cool for an hour, then remove the rear bleeder cap and radiator cap.
• Fill the coolant reservoir if necessary, and fill the radiator until fluid spills from the rear bleeder.
• Install the rear bleeder cap and radiator cap. At this point, the cooling system should be sufficiently purged of air. With the engine running, you should feel hot air from the heater and hear no noises from the heater core. Note: the reservoir usually completes the last little bit of this job for you, so check the coolant level routinely after each drive over the next few days.
• Close the hood and go for a drive! Watch the temperature gauge, listen for strange noises, and check for leaks upon return.

This procedure originally appeared as part of Rick's SE-Rious Procedures created by Rick Zotz which appeared on his excellent site www.zotz.com.