Hi, Could anyone tell me the thread size of the connectors on the brake pipelines, they appear to be 24 tpi but cannot seem to find any dies the correct diameter? Thanks

 

I haven't checked, but try looking up, BSF (British Standard Fine)
OR British Standard parallel pipe thread (BSPP)

EDIT:
You got me curious, so I went out to the garage and checked.
Definitely 24 tpi...
When measuring the size I get 3/8.
So just standard 3/8 fine thread _ so it would appear.

 

Thanks Jeff,

However I am a bit confused still, as all the 3/8" threads are:

BSW 16 tpi
BSF 20 tpi

UNC 16 tpi
UNF 24 tpi
SAE Regular 24 tpi

the last 3 are US threads and unlikely to be used on UK cars in the 1960's,
the only other 3/8' thread I can find is the:

Admiralty Fine Threads 24 tpi

I have in the back of my mind (from my past engineering days) a feeling that there was a special thread for brake pipelines, I've even pulled out my Mechanical World Year Book, 1969 edition (Engineers Bible, published since 1887), but still no result.

I have also checked through my engineering stuff and found a UNF 3/8" 24 tpi Tap & Die, which seems to be the exact same size of my Brake pipeline connectors ???

So all seems to be sorted and I can go ahead with my restoration and refitting the pipelines.

Thanks again,

Ivor

 

Brake pipe sizes found are :-


Most common are 3/8 x 24NF, 7/16 x 24NS, and M10 x 1


All threads on the Mk2's are generally UNF, not sure why we brits took on the UNF, but seems that the unified threads were based on the BSW thread patterns, and BSF was used in the States until steel bolts replaced the iron bolts, useless info for your grey matter

 

There still are some BSF threads here and there, most on the SU crabs, the BSF wrench sizes anyway.
The drain tap on the rad is BSPP.

 

Jon & Jeff,

Looks like 3/8' x 24NF is the one then, maybe Jaguar wanted to sell their cars in USA and tried to keep to the US threads to help sales !!!

Thanks to both of you for your help

Ivor