Brake pipes

Because stopping is apparently important.

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A bit like the fuel lines the old brake lines on our car were attached to the body and specifically shaped by the old vehicle. It was much easier to replace them than to re-use the old ones.

Also, our car was an ABS model. It is common for the Exocet build to delete and remove the ABS. See our earlier posts about the process of deleting the ABS and the change that makes here in our old post

So, we now need to run all the pipework back to the Servo. There are 4 pipes needed

  • Servo to front right
  • Servo to front left
  • Servo to Rear splitter
  • Rear splitter to Rear Right.

The Rear splitter is part of the brake hose kit, and so this is already taken care of by way of a small block at the rear, attached to the sub frame behind the driver’s seat.

The first thing to note, all of the brake connectors on the MX5 are M10 x 1. This means they are M10 in width and the thread pitch is 1mm. So, if you are buying replacement connectors, they need to be M10 x 1. All of the connectors needed are male, you don’t need female connectors. The copper pipe is 5mm in width. You can re-use the old connectors if you need, just cut them off of the old pipe and clean them up.

First things to note, when making up new brake pipes, put the male connector on first, with the threaded end facing the end that you are about to work with. You will be putting a flare on the end of the pipe, so you won’t be able to slide the connector on after.


Putting a flare on the pipe does require a special tool. Enter another £10 tool in a red plastic case from eBay, but possibly worth buying a better one as these cheap ones are rather annoying.


To start with, make sure you have a clean cut on the end of the pipe and that it is not crushed. A pipe cutting tool uses a rotating blade to cut slowly through the pipe by tightening the blade against the pipe, rotating the cutter until it feels loose, tightening it again, rotating, tightening etc. This gently cuts through the pipe without crushing it.

You then clamp the holder onto the pipe, then you use a cap which pushes a ballon shape into the pipe, then uses a threaded, pointed tool to force the flare into the end of the pipe until it is seated in the grove of the clamp tool. This process crates a twin flare, which is important as a single flare will not be able to withstand the pressure of full braking force.


It is at this point that I will say that the replacement copper pipe is much more flexible and easy to work around corners than the old pipe. The downside of this is that it is also easily over bent and crushed. Our £10 kit came with a pipe bender, but small adjustments can be made by hand, just be careful not to kink the pipe. Our main issue is that it seems impossible to make the pipe perfectly straight, as it was posted to us in a coil


But with some gentle work, the pipe can easily be turned back in on itself. This above pipework was needed to stop the old ABS servo pipe from fouling the body, hence why it now loops outside of the chassis.

The IVA guide states that the pipework must be secured, but gives no specific details of how often it needs to be attached, merely that it must be secured appropriately. We have taken the idea of “more is less”. So as mentioned in the fuel lines post, we have used some 10mm spacers and some longer bolts, to hold the brake lines above the fuel lines, using the same rivnut holes, and have secured it at about 10cm spaces.


When screwing the male connectors in, they screw directly into the brake pipes, which you hold in place with (in our case) a 19mm spanner. This then flattens out the end of the copper pipe to ensure a good seal. We used a total of 30ft of copper hose and 10 new connectors. And about 900 P clips, which we had to buy more of in the end.


Welcome to Twits with Spanner. A blog following two chaps as they attempt to build an Exocet kit car with bits from a donor MX5, spanners and lots of hope. Read more about us