Replacing the Water Pump
By Rick Zotz
For about three months, my car had been mysteriously loosing
coolant. The reservoir level would remain full for a few days, then suddenly drop one or
two inches in a single day. I soon discovered the leak was coming from the vicinity of the
water pump, so I embarked on one of the longest, most frustrating maintenance jobs I have
performed in many years. I hope my experience will provide some assistance when you are
eventually challenged by the same task. Is the effort worth saving $250 in labor? You be
|Permatex Super Grey RTV Silicone Gasket
||This is a step above the Permatex Super Blue
recommended by Nissan
|Loctite PST Thread Sealant
||Much better and easier to use than Teflon tape
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
Tools and supplies:
- distilled water;
- power steering fluid;
- 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;
- brake cleaner or equivalent non-residual solvent;
- kitchen plastic wrap;
- empty plastic jug;
View the photos
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Remove the right motor mount insulator pivot bolt using a ratchet and
- 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
Siesta time! Go eat lunch and drink your favorite
- 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
- 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
- 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
- Install the right motor mount only with the pivot bolt, but do not
- 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
- 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
- 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.