Spit / GT6 brakes

[npanne]

Two quick brake caliper questions:

GT6 calipers - with the 16PB units - is there an easy way to tell whether they are imperial or metric? Are they stamped / cast with anything that differentiates between them?

Spit (Mk IV) calipers - would they have had imperial or metric hose connections? I'm guessing imperial, as there seems to be no change, but don't want to be guessing when it comes to brakes.

Thanks

[Nick Jones]

I think the markings are as follows

16P original imperial to approx '68
16PB later imperial to approx '72
M16 metric versions post '72

16PB and M16 look very similar (same dust cover fixing) but M16 has metric threads for the pipe and bleed nipple and the fixing holes are slightly larger (shouldered bolts used on later TR6s to accommodate).

There is also a difference in the pad retainning pin sizes.  16P has big pins, M16 has small pins - not sure which the PB has....

People who actually know feel free to correct!

Nick

[npanne]

Thanks Nick,

The calipers I have came from a '73 car, so should be metric. They're marked 16PB, but also have an 'M' stamped near the mounting holes.

Oh the joys of collecting components from various vehicles!

[Clive]

Try screwing a 3/8 unf bolt in the caliper. If it is a good fit, then imperial. If not, you have metric. I have metrics on mine so will check pin sizes in a bit, or if you are passing I have a box of metric fittings that you can try too.
The flexi is the same in both cases.....(it is the short link pip that was butchered with metric one end and imperial t'other)

[Gt6s]

Gt6 imperial calipers use 1/4 in pad pins, the later metric calipers use 3/16 pad pins.

Laurence

[npanne]

Cheers chaps - measuring the holes for the pad pins confirms I have metric calipers - at muchly.