RV8 water pump overhaul
Ross Boyd posted a query on the V8BB seeking help with his water
pump overhaul. (Dec 09)
Ross Boyd's V8BB posting said I recently had an
exchange water pump provided, but found the front pulley is
in a different position if you are using a standard 3.9 assembly
and your car has air-conditioning. You will need to have the
pulley pressed on further to align with the other belts, so
it is important to check before reinstalling the new pump.
Stuart Middlemiss responded saying yes the Land/Range
Rover water pump is STC483. This is the pump used on the RV8
but it seems that Rover shortened the shaft a little for the
RV8. If anyone wants to have a STC483 re-engineered to fit the
RV8, the gasket face of pump casing to front face of flange
is 87.5mm to 90mm. Measure the old one - discrepancies are probably
result of original re-engineering of Land Rover standard pumps.
Ensure pulleys are aligned - the alternator pulley can be brought
forward by spacing washers if necessary. But of course Clive
Wheatley can supply the water pump which will fit out of the
Peter Garton in Germany had two questions! What is it
that goes or wears in the RV8 water pump and roughly at what
mileage? What were or are the symptoms you experienced, Ross?
Porter provided an explanation - it is the main shaft bearing
that goes on the waterpump. This is due either to overtightening
the fanbelt or more commonly on the RV8, to failure of the bearing
due to its lubricant (grease) drying out over time. Bearing
wear allows slight axial movement of the shaft which lets coolant
past the shaft seal through to the bearing which then increases
are droplets of coolant dribbling from a small drain hole in
the pump body just below the shaft. The droplets are flung out
when the engine is running which can be seen as dried water
spots on the underside of the bonnet and on the inner wings
etc in line with the pump pulley. Wear can also be detected
by being able to rock the pulley from side to side by hand.
The seal can fail at quite low mileages, mine went at about
8,000 miles. Long periods of little or no use encourage the
grease in the bearing to dry out causing early failure. As with
regular use is best and then the pump would probably be OK for
quite a high mileage.
As Stuart says, Rover shortened the main shaft of a standard
Range Rover pump to aid the fitting of the engine into a smaller
vehicle. Replacement pumps are readily available from specialists
like Clive Wheatley.
Peter Garton was pleased saying many thanks, Max for
your excellent explanation. When I get the Rv8 out of its wraps
in the Spring I'll take a look just to be sure.
Ross Boyd also found that if you have the air conditioning
compressor installed, you will not be able to lower the radiator
as the manual says, unless you remove the compressor first off
the four mounting bolts which also means removing the air conditioning
lines as well and de-gassing the air conditioning. To avoid
this, it is easier to remove the front stabilizer brackets to
each side of the front chassis rails and lift the radiator up
and out by moving the stabilizer bar out of the way to avoid
the bottom radiator hose pipe.
Porter responded saying Ross you are quite correct that
the air con compressor prevents the radiator from being lowered
and removed from beneath the car as it fouls the top hose spigot
on the radiator. The bottom hose spigot on the radiator fouls
the roll bar and prevents the radiator from being lifted out
of the car. It is of course, much easier to unclamp the roll
bar and move it out of the way rather than dismantle the air
conditioning system. Rover's workshop manual does not mention
this so you discover this point as the job proceeds.
another couple of points. On checking the pump for wear by trying
to rock the water pump pulley. Wear is easier to detect if the
fan belt is slackened off a bit first. The other point that
should be mentioned is that the water pump is the same unit
for RV8's both with and without air conditioning. Initially
I went to my local Land Rover main dealer for a pump as the
price was considerably cheaper. There was the new pump on the
main dealer's counter and it looked identical in every way to
the one removed from my RV8. I was really pleased at the prospect
of saving quite a bit of dosh but sadly on closer inspection
of the two units side by side, it was noticed that the main
shaft was shorter on the RV8 unit. Definitely a case of "sod
and his law" once again.