well maintained and working to the manufacturers specifications,
the standard Morris Minor brakes are actually very effective.
Sure, they do suffer from brake fade when they get hot, but
that's an inherent problem with drum brakes, not with the
arise when the brake system is not working at its best. Which
is to say, most of the time, especially as the cars are all
35 to 50 years old now and not everyone has the time, money
or patience to renew the entire braking system. It's money
well spent, but it's money that only a few will be prepared
to part with.
what do you do?
for starters, make sure that your Minor has brake shoes with
plenty of meat left on them. They should be at least 3mm thick
and preferably thicker. What may have been perfectly usable
40 years ago may well be borderline now. This is because the
drums themselves will probably no longer be perfectly round
or may even have worn down and therefore are now a (slightly)
wider diameter. Only 0.5mm less metal on one side means 1mm
overall, and that's 1mm of adjustment that your brakes probably
your drums checked for thickness and roundness, and replace
all the brake shoes.
Although they have probably been replaced with newer pads
with modern materials by now, be careful of breathing in brake
dust! Older brake pads contained asbestos so breathing in
the brake dust from these pads is dangerous! Don't blow out
the dust from the drums. Use a water spray bottle or proper
brake cleaner and dampen everything down first then wipe it
clean. It's slower and harder, but it's Good For You!
Minors built prior to 1962 have 7 inch diameter drums on the
rear and 7 inch diameter drums on the front. I'm not certain
about the Series MM Minor, but all other models can be uprated
to use the later 8 inch drums on the front, as used on the
1098 Minor 1000. This is a straightforward swap, simply remove
the old drums, slave cylinders and backing plate and replace
them with the larger ones, after you've cleaned, checked and
replaced any worn parts of course!
vehicles in the BMC range also used larger rear drums. The
Riley 1.5 and the Wolesely 1500 both used an axle with 8 inch
rear drums. These axles can be swapped for the Minor axle
giving not only larger brakes, but a different selection of
differential ratios. Very useful if you've uprated your engine
boosters are another way of improving your braking system,
but bear in mind they do not make your brakes any better,
they just make it easier to put more pressure on the brake
pads. The braking potential is the same with or without a
booster, it's just easier to apply.
simplest booster to fit is an inline booster such as the Lockheed
VH44. This was a very common booster fitted to British cars
thoughout the 60's and 70's and you should be able to find
one at your nearest wreckers yard. The VH44 is a big large
though at about 9 inches in diameter so it takes up a lot
of the spare room on one side of the engine bay. A bit of
hunting around should turn up a Japanese unit that will be
both smaller and newer.
always, have the booster unit thouroughly checked out before
fitting it to your car. The last thing you want is for something
to break or burst when you next press the brakes a bit hard.
"Disc brakes do not make you stop quicker than with drums
brakes. They are no better than properly maintained drums."
this sounds unlikely, the above statement is actually true,
to a point. If the surface area of the discs that is used
for breaking is about the same size as the surface area of
the inside of the drum then braking efficiency is very similar,
so the statement is correct. But, the big difference lies
in how often the brakes can be used and for how long before
heat buildup causes brake fade. Drum brakes suffer badly from
fade, discs do too but not as badly since the disc is out
in the open air and the heat can dissipate far more readily
than from inside a drum.
disc brake conversions include using the disc from the Morris
Marina or Vauxhall Viva. Fiat discs can also be fitted, but
the Marina and Viva both offer stud patterns that allow you
to use the original Minor wheels.
early Morris Marina has the same stud pattern as the Minor
and as such may be the better choice for you when deciding
which model/year Marina to acquire your discs from.
are a number of kits available on the market that supply all
the necessary bits and pieces to convert your Minor from drums
to discs, and these should be considered first when doing
a disc brake conversion. The research and development has
been done for you and you know the kit will work - if it doesn't,
you've got the law on your side.
Discs on Marina Hubs
Jukka Harkola has kindly sent in the following details on
how he fitted BMW discs to his
used BMW 300-series (E30 type) front discs. Diameter 260
mm, thickness 22, depth 35, diameter of flange bore 66mm.
Marina disc dimensions diameter 249, thickness 9.5, depth
45.7, diameter of flange bore 66.7mm.
On Beemers the disc is fitted on the hub, between the drive
flange and wheel. On the other hand Marina hubs carry the
disc inboard, ie. to change the disc you have to remove
mod is very easy. The outside diameter on the Marina hub
is 66.7 mm. This diameter guides and centers the disc. The
BMW disc is turned on a lathe and the original 66mm bore
opened to 66.7mm. This allows the disc to be fiited to Marina
I used an old pair of Marina discs to make an adapter plate.
The Marina disc has a flange where the bolts are fastened.
I cut the flanges off the discs and cleaned what was left
of the flanges. This left me with a circular disc with threads.
Now it is simple job to fasten the BMW disc to the Marina
hub. Longer 3/8 in bolts are required.
course original caliber will not fit. Any modern sliding
single piston caliper will do, eg. Vauxhall or VW. Four
pots are propably a
very tight fit due to thicker construction. They may foul
the wheel. Caliper bracket must be scratch built to any
caliber but with BMW disc 8-10 mm plate can be used.
Above discs need 14 in wheel. Some wheels may not clear.
I have 14 in. alloy wheels and had to turn the discs to
254 mm to clear the balance weights inside the wheels.
Diameter 247mm, thickness 20,5, depth 44,2, diameter of
flange bore 66mm.
Diameter 256mm, thickness 22, depth 41, diameter of flange
bore 60mm. Diameter 256mm, thickness 24, depth 41, diameter
of flange bore 60mm.
Golf GTi G60 (15 in wheels):
Diameter 280mm, thickness 22, depth 39, diameter of flange
bore 64 mm.