So guys, I need a litle help. I have a non-vrs Fabia, and on the rear I already made upgrade from drum brakes to 232mm disc brakes. Now I want to upgrade fronts from 256mm to 312mm. I already have the full set, the only thing I am missing are the vrs hubs. But here is the tricky question, some mechanics advise me that I need a TDI brake power servo ( I hope you call it like that, I am from non-english speaking teritory).

 

When I upgraded from drum to disc brakes my brake pedal has a little play, about 1.5cm before it starts to brake. Will it be even worse with 312mm upgrade ?

I use 323mm 6 pot front brakes and 256mm rear brakes on standard pd100 brake servo etc. Works fine.

Changes in pedal travel from this sort of upgrade tend to be nothing to do with the servo (vacuum booster). They tend to be to do with changes in the swept volume of the wheel cylinders for a given pedal travel.

 

Rather than listen to mechanics, I suggest you look for a college or university that teaches "Automotive Engineering" to get the theory explained properly.

So in other words you are telling me it will work fine with existing brake servo, there will be no problems ?

I believe you can also use the 2.0 hubs as they also came with 288mm brakes. So 312mm will fit them too.

So in other words you are telling me it will work fine with existing brake servo, there will be no problems ?

Well. I am doing so. :P

I was under the impression all the master cylinders and servos were the same, the only exception being cars with ESP that have a different MC.

I believe you can also use the 2.0 hubs as they also came with 288mm brakes. So 312mm will fit them too.

Very true. However probably harder to find than vRS ones.

Very true. However probably harder to find than vRS ones.

That is true. I forgot people habg on to the 2.0 as their the mustang slayer

So in other words you are telling me it will work fine with existing brake servo, there will be no problems ?

I may have over-simplified a bit.

 

The servo has nothing directly to do with pedal travel beyond that travel reduces when the vacuum is getting exhausted (to experience this, pump the pedal until it goes hard with the engine off, then start up with your foot on the brake and feel the pedal drop).

 

What will affect your pedal travel is if your new brakes have higher volume wheel cylinders which require you to move more fluid from the master cylinder to get the pistons to move a given distance. As Jason says, it's by no means certain that new callipers will have larger total piston area though.

Tarox make sure their larger brakes can still use the use the standard master cylinder to provide enough fluid. I'd have thought it would have been the same for AP, brembo etc