Fit larger 22mm Master cylinder & Mk3 Brake Booster into your Fox by the brit

By diyauto
( 2 )

Fit larger 22mm Master cylinder & Mk3 Brake Booster into your Fox 

Compliments of the brit @


It's easy, here's how:

Take one crappy older fox booster, and a newer mk3 one that will allow you to bolt up the matching later 22mm master cylinder:

Compare - mk3 has a ball on the end, fox has a nice adjustable 'bolt through' design. You need to swap the ends. Told you this wasn't rocket science.

This is what you need from your old fox booster:

Measure from the main body of the booster outwards towards the brake pedal connection. I measure 4" because it's a nice easy number.

[NB: Ignore where the ruler is placed in the photo - measure from the booster body towards the end, not from the end towards the booster. The arms on each booster are different lengths, so you will screw up if you go from the pedal connecting end in! If you can't understand any of this, don't do it, or pay someone else to do it. If you need a disclaimer: This is all theory. The photos are actually of a 1:14,027 scale model of a fox that i'm building for off road use/display only. That ruler is actually the size of a pre-pubescent knats ballhair. Thanks.]

Cut off both of them, and unless you can think of something to do with it, throw away the mk3 ball-ended fitting one. You must keep the 'forked bolt through' end that attaches to the fox brake pedal, and of course, the mk3 booster.

Weld the fox end onto the mk3 booster body. The nice part about it all is that the fox bolt-through end has a good range of adjustment and the whole thing can move at two different parts (at the pedal and in the booster) so you can't really go wrong!

Just in case anyone cares, the mk3 booster lines right up to a early-ish mk1 booster bracket. Fair enough.. NB: This is just FYI - do not read too much into this!!

Don't forget to give it a coat of paint, or something to stop it picking up any rust in the future. 

Yup. You're done. Now go bolt it in just like your fox one did, and bolt the 22mm MC to it. That's it! This booster is for Kinavo, Fox-N-It and myself have both been running this style setup for a while now, check out photos of our engine bays if you care that it looks tidier too.