I have a leaking rear wheel cylinder on my striker which has a live axle.
I am trying to identify the correct cylinder, I have measured the cylinder bore as 17.50mm which gives me two options QH BWC3022 (lockheed) or QH BWC3282 (lucas).Please can someone tell me what the difference is between them, is one metric and one imperial.
Thanks Matty

If it is an imperial size cylinder I would suspect that the pipe nut thread would be UNF , metric cylinder would have a 10mm thread.

I used M16 caliper with small bore at rear - passed ok..
Cylinders thread..

(Try a metric bolt tin the thread)

[Edited on 29/11/12 by johnemms]

You will never find Lockheed brakes on a 70s Ford

Wheel cylinder bores are Imperial car sizes were 0.625" 0.7" 0.75 " ie 5/8", 7/10" and 3/4" From your measurement you have 0.75" cylinders which is listed these days as 19mm

Mk1 Escorts with 8" brakes have single piston floating wheel cylinders with 7/16" UNF threads 0.75" bore . BWC5003

MK2 Escorts have double piston wheel cylinders with M10 x 1 threads BWC5090