MG MGA Twin Cam Workshop Manual page 66

c
THE COOLING SYSTEM
Fig. C.5
A sectiont!d view of the water pump showing the
deorance between the body and tht! pump vane
drajn taps as described in Section
C.2.
at the same time
remembering to keep the coolant liquid for re-use if it
contains anti-freeze mixture.
Release the clips on the top and bottom water hoses
and detach the hoses from their connections.
Remove the three bolts at each side securing the radi-
ator core to the body and lift out the radiator.
Disconnect the dynamo leads, remove the dynamo
attachment bolts, and take off the dyrtamo and fan belt.
Remove the bolt and the three nuts from the studs
securing the pump body to the timing case, also the bolt
holding the aluminium inlet pipe. Release the clips on the
water outlet and by-pass hoses. The pump and fan assem-
bly together with the inlet pipe can then be withd rawn.
Replacement of the assembly is a reversal of the above
procedure, but care must be taken to see that the joint
gasket between the pump
body
and the
timing
ease is
in
good condition.
Section C .8
DISMAN JUNG AND REASSEMBLING THE
WATER PUMP
When the fan and water pump assembly bas been
removed as indicated in Section C. 7 the water pump
may be dismantled in the following manner.
Unscrew the four set bolts and remove the fan blades
from the bub. Unscrew the nut and spring washer from
C.6
the end of the pump spindle and pull off the fan hub with
a suitable extractor. Release the two bolts securing the
aluminium inlet pipe to the pump body and remove the
pipe.
Remove the felt seal and the Woodruff key from the
spindle, taking care to remove any burrs from the key-
way. W ithdraw the dished oil
seal
washer.
R emove the four bolts securing the pump body to the
scroll casing and separate the two parts. Gently tap the
spindle rea rwards out of the pump body and remove the
flat sealing washer, the fell seal, and the dished sealing.
washer. The rubber sealing gland is withdrawn from the
spindle after removing the felt seal locating circlip.
Should it be necessary to remove the ball races, the
front one can be withdrawn with an extractor.
Wh en the front bearing is removed it releases the d is-
tance tube between the bearings and gives access to the
rear bearing re(ajning circlip. Remove the circlip and
withdraw the rear bearing if required.
R eassembly is a reversal of the dismantling procedure,
but care must be taken to see that the seal is in good
condition before proceeding.
Before assembling the pump body to the scroll casing
ensure that a running clearance exists between the body
a nd the pump vane as indicated in
Fig. C. 5.
No adjust·
ment
is
provided for varying the designed clearance,
which should always be present.
Renew the pump body gasket and the felt seals if
necessary.
Repack with grease to Ref. C.
Section C.9
RADIATOR PRESSURE
VA. L VE
To prevent loss of coolant due to vibration of the
valve in the filler cap, a 7 lb. (3·175 kg.) remote radiator
pressure valve is now fined. Cars equipped with the new
valve are numbered as follows : Car Nos.
575, 613, 623.
633, 648, and
from
652
onwards.
To modify an existing radiator the following procedure
must be carried out.
Remove the existing filler neck from the header tank,
rotate through 180°, and replace. .
Fit the pressure valve (Part No. AHH5903), together
with its bracket (Part No. AHH5906), to the inner face
of the left-hand air duct.
F it the rubber connecting hose (Part No. AH H5905)
from the filler neck to the valve, and the overflow pipe
(Part No. AH H5907) from the valve to the d rajning
point. The overflow pipe
is
re(ajned in position at its
lower end by a clip (Part No. PCR0607).
MGA (Twin C.m). Issue 2. 19422