Classic Bike Guide
Please take heed
I dare say I am late to the party with this, but I couldn’t not comment on the potentially dangerous replacement brake pipe make-up described in the Project BMW update in the June issue of CBG.
You have put the wrong flare on your self-made replacement brake pipes, which has potential safety implications. The photo clearly shows that BMW used, not unsurprisingly, a DIN or ‘bubble’ flare on the OE brake pipe, but the replacement pipe made up has had an SAE double flare formed on it – in the picture of the flaring operation, ‘SAE’ can be made out on the tool and the picture of the finished article is completely different in form from the original. These flares are not interchangeable, as the flare nuts and the machining of the seat at the bottom of the thread are different for the two standards. While the arrangement produced may well assemble and may well seal, it won’t fit as it should and could potentially fail in use.
A DIN flare tool of the same style as the SAE tool shown is around £34 from eBay, so it may well be cheaper to buy OEM replacement pipes than buy the correct tool and correct DIN nuts to accompany it if you are not likely to be working on German vehicles in future.
My employer is doing up a 1979 VW Type 2 camper that required brake pipes I got tasked with making. He had bought an SAE flare tool before starting the job, but ended up exchanging it for the DIN version after I noticed. Not worth taking chances with brakes!
Many thanks Nigel and I hope this helps others. It certainly has me, as I’d just made some pipes up for our Morris Minor – Matt