[ Cooling system ]
62 July 2019 MiniWorld
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Heater valves have a bad habit of leaking and sticking, usually in
the off position. Also the gaskets sometimes leak. Lubricate the
pivot, the cable and also the plunger lightly, if it seems to be stiff.
If it leaks then you should replace it.
Heater hoses are very often neglected. They do not need to be
replaced as often as radiator hoses but should be checked and
replaced when necessary. Heater leaks will show up as a damp
or wet patch on the carpets or mats. Replace the matrix or hoses
when this happens, as the problem only gets worse.Late 1970s-onwards Minis have a one-piece engine-side radiator
cowl/fan shield. Once the radiator top bracket has been released
from the thermostat housing and the top and bottom hoses are
disconnected, all that needs to be done is to remove the single
bolt at the base of the radiator which will enable the radiator
assembly to be lifted out fairly easily.
Pre-1972 Minis have an outer radiator cowling built into the inner
wing. This makes removal difficult. Patience is required.9
If your Mini's water pump is more than
around five years old it is worth replacing
it. It is more conveniently done if the
radiator has already been removed for
hose renewal and flushing.large-impeller pump will fi t small block
engines with the exception of early 850
and 997 blocks. Mini Spares also sells
a very good water pump fi tting kit for
both bypass and non-bypass pumps.
Very highly-tuned Minis may
benefi t from an oil cooler to take
excess heat from the oil and help
keep engine temperatures where
they should be. Always fi t an oil stat
to prevent over-cooling of the oil.
The heating system is a part of the
cooling system and needs to be kept in
good working order, not only to keep
the occupants of the car warm and the
screen demisted during winter, but
because, particularly on Minis with the
smaller-capacity radiator, the heater
can be used as an additional radiator
in heavy tra c or during a long, steep
climb. When refi lling the cooling
system after work has been carried
out, always make sure that the heater
controls are in the ‘ON’ position, as this
will help prevent air locks. The heater
can be bled by briefl y disconnecting
the return hose where it connects to
the bottom hose while the engine is
running but not at full temp. This is
the standard method for carrying the
job out but great care is needed as the
coolant will be hot and the connection
is quite close to the fan. Always wear
protective gloves and eyewear. If the
heater still does not work, and there is
no airlock, it could be that a heater hose
is kinked inside the car or the heater
matrix is blocked. The heater matrix
can be fl ushed through with a garden
hose but, unless you are confi dent,
it is best to drain the heater and
remove the matrix from the car fi rst.