Hi all I'm currently fitting a floor mounted pedal box with new master cylinders which have a 3/8 fitment. The car is already built with all brake lines fitted and have m10 male ends.
Question is will it be ok to fit a 3/8 male to m10 female adapter on the master cylinder to let the current line fit. Will it affect flow or performance?
I would change the line but its very hard to get to under the car. For the front section I just bought a tee piece that the 2 front m10 went into then a new line coming out with 3/8 on the end so its a direct fit.

Many thanks

The brake pipe is still 3/16", the unions can't affect the "flow". Brake fluid doesn't exactly flow it is compressed.

Ok thanks for the reply. I think I'll look for the adapter then as it would save me the hassle of changing the whole back brake line or cut and re flare as I don't have the tool

As Peteff said. Even a passage slightly bigger than pin hole will flow enough fluid to work a disc brake.
In the old days of drum brakes a small volume of fluid had to flow tom move the brake shoes but with disc brake there is practically no movement of fluid in normal operation.

You may have problem finding a Metric to UNF adaptor you could use a metric joiner and a short length of brake pipe with a M10 at one end and UNF at the other.

Steve, sorry been really busy but off work from Friday if you still want that part?

Is that the bracket? If so that would be amazing and really help me. Did you also fit the spring to the back of the bracket on yours?

As BT points out I doubt very much if you will find an adaptor , I've never seen one in 46 years in the motor trade. Make up a short joiner as suggested. If using UNF and Metric pipe fittings on the same car is good enough for RR then it's good enough for us

I have found the adapter but only from the US at the minute so will be costly