Sorting out TR3 through 4A front Calipers
There are 3 types of brake caliper for the TR3 through TR4A
Type 1 is the alloy caliper which ran on the TR3 from TS 13046
up to about
TS 56000 depending on whether it was a wire or steel wheel car
(TS 56376 and
TS 56383 if you want to be clever about it!). This is the
one with the
external linkage pipe between the two halves.
Type 2 was a cast steel caliper which was also used on the late
TR3A, early TR4's (so
TS 56377 / TS56 384, thru the TSF series TR3B's and to CT 4387TR3
what people refer to as the 'long' caliper. Pads are the same
as Type 1.
Types 1 and 2 Pads are the same, but the springs & retainers
are different. They appear equally
to repair as the placement of the cylinder and dust seals is
very fiddly. It does take some finesse to
keep the piston from tilting as you slide it into the bore. If
it starts to
tilt, you must immediately apply pressure only to the opposite
straighten it out, or else you'll have to remove it again. Generous
lubrication with silicone brake fluid or brake grease helps too. I
use the edge of a cut alloy tube to place these when I have to
- otherwise I
just buy exchange units if they are available. The
only part not readily available is the cross-over tube on the "type
1" calipers ... but they are relatively easy to fabricate.
Type 3 is the later type which was used on the later TR4, TR4a
to the early TR6 I believe and is the best of the bunch. These
seem a lot
easier to do at home, even though you need to be very careful
the inner and outer bolts to their different settings. Again
I'm now getting
these reconditioned as a lump very cheaply.
You can also use a single pot Jaguar caliper (nearly fits),
a twin pot
Austin Rover caliper (fits like a dream) - both using standard
or some jap stuff if you are that way inclined, plus of course
all the go
faster alloy things, with vented discs etc. etc. Ive used both
the Jag and
the AR twin pot (nearly period - 1971 for these) with good results
are commonly available - get in touch if you want to know more.
stuff is good but largely illegal for most motorsport here unless
totally free - I have next to no experience here consequently
but im sure
there are others who have.
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