Brake/clutch pipe

Hi All…hope you can help…1960 xk150…refurbing brakes/clutch replaceing corroded steel with cunifer…i currently have a mixture of sizes at the clutch/brake master cylinders…so what size should i have in/out of both cylinders…some pipe has been replace prior to me getting the car…3/16 cunifer to the front flexis…i have tried to search and look in Viart book and it says All 150 disc brake pipes are 3/16…but does that include the reservoir feed into the master…thanks…Steve

Don’t know what the XK has originally, but feed from reservoir benefits from 5/16" (8 mm) lines.

On my 58 OTS, one supply line appears to be a replacement, but the other is, I believe, original. They are both 3/16ths.

Steve, if the original was 3/16" I would replicate it. You don’t need anything bigger as very little fluid should be passing through those pipes in normal use (basically none, unless you have a problem).

Hi All…thanks for the replies…but im still not sure on what size pipes there should be to the clutch and brake master cylinder…dont think any of my pipes to the masters are original. …so question is what size i/p and o/p pipe to both masters was originaly used…thanks…Steve

Hi Steve,

I can’t guarantee the originality of the pipes on my car, but they do look old. They are 1/4" steel lines from the reservoirs to the master cylinders. Were the originals steel?


Currently my inputs are 1/4in…one steel one copper…my outputs are 3/16 one copper one cunifer…I think original was all steel…Steve

Hi Steve,

Just checked - the lines coming out of the master cylinders are 3/16" and magnetic. They are light coloured - metalic greyish, maybe plated. Since the three lines coming out of the brake distribution block are the same as these, I am more inclined to think them original.


Hi Steve, my pipes from reservoirs to master cylinder are 1/4" steel the entire length. There are variations with later models having a hose in the pipe line, not sure if yours is an ‘S’ model again different to the non ‘S’ variants. Otherwise steel tube used throughout on mine.

Thanks John and all for the replies…so it looks like i/p pipes should be 1/4in…o/p pipes 3/16…will replace all with cunifer…Steve