On 7/15/2011, Bob Donahue wrote:
"I'd like to get a flare nut wrench for the hydraulic lines on my '71 MGB. What size are the fittings"?

If you are buying replacement parts, don't bet on it being original. These days lots of replacement hoses are being made with metric hex sizes.

On 7/16/2011, Glenn Schnittke wrote:
"What I've seen in the shop is -
Actual flare fittings (hard line to caliper, rear union, etc.) - 7/16" wrench. Thread 3/8x24, pretty regular.
Hoses - again 3/8x24 thread.
Wrench size could be 9/16, 14mm, 15mm, or 5/8.
Bleeder screws - What a cornucopia! recently I've seen 7mm, 8mm, 5/16", 7/16" and 3/8".

In the real world, hydraulic hoses MUST be made with the correct threads to mate with connecting pipes and cylinders. However, these days hex fittings on replacement hoses may be changed to metric sizes. This is a result of current world wide sourcing of replacement parts, and the world at large is becoming increasingly metric.

On 7/16/2011, Paul Hunt wrote:
"Just based on my 73 and 75, the two need different spanners in various places, and they aren't always AF sizes i.e. Imperial. My 1975 (date of publication) Workshop Manual details both Imperial and metric hydraulic fittings and how to identify them, so either they changed what they were using at some time (or even from time to time) or it varied from market to market".