I am looking at new brake discs for my 2015 fiesta ST. The current ones seem to be 258mm slotted and drilled brembo discs (which I can't find anywhere). When I look online only 278mm discs show and with some reading it appears these are the correct ones for the ST, I was wondering if anyone knows why it may have 258's on currently and if I buy 278mm discs do I require any additional parts, shoes, calipers, etc?

Thanks in advance.

10 hours ago, Owen Goodson said:

I am looking at new brake discs for my 2015 fiesta ST. The current ones seem to be 258mm slotted and drilled brembo discs (which I can't find anywhere). When I look online only 278mm discs show and with some reading it appears these are the correct ones for the ST, I was wondering if anyone knows why it may have 258's on currently and if I buy 278mm discs do I require any additional parts, shoes, calipers, etc?

Thanks in advance.

Hi,

Are you sure it's a proper ST? Not a lower spec model that's been made to look like an ST?

ST's should be 278mm fronts with disc brakes at the rear.

All other UK trims are 258mm fronts with drum brakes at the rear.

The pads and calipers/carriers are different so I can't see how anyone could accidentally fit the wrong discs.

Hi Owen,

Can't help much here but 278mm front is the standard size for a Mk 7 ST. 258mm is the size for other versions and there are several listings on Ebay etc for Brembos in that size for non-ST cars.

You normally see people fitting bigger brakes to an ST or fitting ST brakes as an upgrade on other models, so why go the other way is a puzzle, unless, as Tom suggests, its a "lookalike" or a bodged damage repair using parts from another model.

In my opinion 278 mm front discs are already undersized on a Fiesta MK7.5 ST. I would not want to drive one with 258 mm front discs.

If it is a real ST 1.6 EcoBoost it would be interesting to know why someone would have bothered to decrease the brake disc size to 258 mm. As mentioned above a bodged damage repair would not be unlikely.


If it is a real ST 1.6 EcoBoost it is strongly advised to either install the original 278 mm discs and brackets or upgrade to the 300 mm Focus ST170 discs and brackets.

2 hours ago, TomsFocus said:

Hi,

Are you sure it's a proper ST? Not a lower spec model that's been made to look like an ST?

ST's should be 278mm fronts with disc brakes at the rear.

All other UK trims are 258mm fronts with drum brakes at the rear.

The pads and calipers/carriers are different so I can't see how anyone could accidentally fit the wrong discs.

Hi mate,

Yeah definitely a proper ST, V5 checks out as one, 1.6L turbo, etc.

I will order 278mm fronts in that case.

Thank you.

Be aware the 278 mm front disc brakes use different brackets/carriers as the 258 front disc brakes.

It is not just changing discs.

1 hour ago, JW1982 said:

Be aware the 278 mm front disc brakes use different brackets/carriers as the 258 front disc brakes.

It is not just changing discs.

Just to confirm, Euro car parts accidentally gave me the wrong discs 278mm for my Fiesta 1.2 (258mm) and no way would the brackets and calipers fit that size bigger disc.

20 hours ago, Owen Goodson said:

The current ones seem to be 258mm

Just a thought noting the "seem to be" - were you 100% confident of the measurement?