XK 140 Braking upgrade

Good Day Listers,
I have searched the archieves regarding braking upgrades and learned about front disk brakes for the XK140 and the advisability of adding a servo and the need for front to rear proportionality in hydrolic pressure to front vs. rear drums.
I am looking for comment and advice from anyone that has used “XK Brakes” for the upgraded servo and master cylinder parts. The picture is from their offering. I await some idea of price from the vendor, and suitability from the list.

This is a beautifully made unit but the servo will be required to reduce brake pedal effort. The proportioning valve will adequately reduce rear brake pressure to prevent rear wheel lock up but the 1” tandem master won’t supply enough pressure to the front calipers to have reasonable pedal effort. XKBrakes will not sell to the USA. As far as the disc brake conversion I would recommend the fossewayperformance.co.uk
Performance Vented Disc Conversion. Solid discs will overheat with spirited or mountain driving.

Hello Lian,
I did make the brake update with the set of XK Brakes.
It works fine, for the front disk brakes and drum brakes at the back. The proportioning valve is working from 0 till maximum pressure.

Best regards,

Thank you for your response. I have learned that XKBrakes will not sell to the US.


Hi, I just had my XK140 front brakes converted to the Fosseway disk brakes. I considered the XK Brake cylinder and servo, but thought I would try first with the original master cylinder.

Now that I have driven the car for 1500km I am sure I will not need a servo. Surely, if my wife would drive the car things might look different, but she enjoys being driven by me :slight_smile:

I do not think I need a proportioning valve either. However, I might put in a 10 pound residual valve for the drum brakes close to the master cylinder.

Thank you for the info. I’ll likely go your way with the upgrade to front disks. For the moment, I’ll bask in the originality.