MiniWorld July 2019 61
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Check the condition of the hoses. This one is close to as bad as
they can get.5
A thermostat stuck open will prevent the engine from reaching
working temperature and also mean that the heater will not
work properly. If it is stuck in the closed position then rapid
overheating will occur. When replacing a thermostat always
use a new gasket and make sure that all residue of the old one is
removed. If not, it will leak.
A bypass hose, where fitted, should be checked and replaced if
there is any doubt as to its condition. Here the head has been
removed to expose an old concertina type of bypass hose. Old
hoses of this type are the most prone to failure.
8
Hose clips need to be fully tight. Anything less and they will leak!
is changed before it is allowed to
perish, it will never cause a problem.
Until 1980 there were two main types
of Mini radiator fi tted as standard:
the small capacity 13-gills-per-inch
type and the larger capacity 1964-on
Cooper/S-derived 16-gills radiator.
From 1980 all Minis were equipped
with the larger capacity radiator.
Further changes were made with
the addition of an electric fan when
injection Minis were introduced,
and, when MPI models came along,
a redesigned radiator was front-
mounted. All can deteriorate and
need to be regularly checked.
Upgrades
There are a number of upgrades that are
possible, some for higher performance
and some for longevity and reliability.
All of the hoses, including the bypass
if fi tted, can be replaced with longer-
lasting and more reliable Kevlar or
silicone hoses. These are available
as a kit from Mini traders priced
from just over £70, depending upon
model. For pre-injection Minis, fi tting
the larger S-capacity radiator to an
earlier Mini will help keep things
cool. When originality is important
it is possible to have the original
metal-tanked radiators recored to S
capacity. If replacing a standard later
rad on a hard-driven or tuned Mini,
even a mildly tuned one, it is worth
considering a more e cient two- or
four-core radiator of the type available
from specialists. This will help prevent
the tendency for the engine to run
very warm when idling in tra c.For highly-tuned Minis an alloy high-
performance radiator will improve
matters even further. If the radiator
has been removed it is advisable to
renew the water pump, unless it has
been replaced in the last three to four
years. There are four di erent types of
water pumps for Minis. GWP132 is the
original small-impeller type for small-
bore blocks; GWP134 is the 1300cc
large-impeller type; GWP137 is a non-
bypass version of GWP134 and GWP188
is for Twin-Point (MPi) Mini engines
only. If you are not sure which type
of pump you have, the small impeller
protrudes from its block mounting
face by 7.9mm ( ⁄”) and the large
impeller by 15.75mm ( ⁄”). Mini Spares
produces upgraded large-impeller
pumps with a three-year guarantee
and it is worth noting that the GWP134 »