Water Pump Change
How to change the water pump in a suprex engine
Faulty Water Pump?
The water pump is designed to leak slightly when it needs replacing. Most of the time it is worn
bearings but the have been known to break blades. This reduces the performance of the pump
and bits of the blade can block water ways and make noises in the water pump housing.
If you are losing coolant or the car over heats easily, you might need to change the pump.
Draining The Coolant
You don't have to drain the coolant if the water pump bearing have failed, however, it is
a good idea to do it anyway and if there is any damage to the blades then the coolant
may be contaminated with metal particles. Changing the coolant can be found here.
Removal Jack the car up, remove the rear wheels, disconnect the battery and remove the arch liners on
both sides. Remove the 3 plastic nuts with a 10mm hexagon socket and pull the arch liner out.
Protecting the belts is a plastic cover. Pull out the front plug...
...followed by the rear plug. The cover will now come off the car.
Disconnect the X-frame by removing the arrowed bolts on both sides.
This gives access to the engine mount bolts.
Use a trolley jack and a piece of wood to support the engine under the gearbox.
Take a 15mm spanner and loosen the adjuster nut.
Pivot the alternator backwards to loosen the belt.
If you have air conditioning then there is a 2nd auxilary belt that needs loosening.
The tensioner wheel is on the left side of the engine. Use a Torx45 bit. (picture to be added)
You must also remove the main pivot bolt (16mm) at the top of the alternator. As you
have just slackened the belt it is fairly easy to get to (arrowed in green below).
A square nut will fall off the back, don't lose it. If you have a magnet on a stick you
can position it on the rear nut so it doesn't disappear. Slide the bolt out. It will easily
slide out above the engine cradle if you raise the engine up slightly on the jack.
You will be able to view the face of the water pump pulley. Remove the 4x
4mm hexagon cap head bolts and the pulley will come off of the water pump.
This shows a better view of the water pump pulley.
Remove the 7x Torx bolts using an E10 socket (circled green).
The 16mm alternator pivot bolt is already remove (circled red).
Lever the water pump out of the engine. It will look like this.
Clean the mating face of the engine where the new water pump will touch to ensure that none of
the old seal will affect the replacement. Ensure that the new seal is fitted correctly and put the
new water pump in place. Place all the bolts in hand-tight first so you don't deform the new seal.
Torque the 7x bolts to 10Nm, replace the pulley and torque the 4x 4mm bolts to 10Nm also.
Replace the alternator pivot bolt and torque that to 25Nm.
Re-tensioning The Belt
Place a 15mm spanner onto the nut and an E10 socket onto a torque wrench and onto the end
of the bolt. Set the torque wrench to "undo" and dial in 45Nm. Push the handle of the torque
wrench and the alternator will pivot up and the belt will tighten. When the torque wrench
reaches 45Nm you can tighten the adjuster nut with the 15mm spanner.
Replace all the parts you took off, make the car safe to drive, top up the coolant that
you lost when you took the water pump out and go for a drive. Keep an eye on the
coolant temperature and recheck the coolant level regularly for a few uses.