604 front brakes onto a 505 STi

[Haakon]

Can I simply bolt on 604 calipers and hub/dics to an 84' 505 STi (ie are the struts/stub axles/caliper mounts/master cylinder the same)?
The discs are worn out and I may have access to a set of 604 brakes.

 

[davemcbean]

Yes it all bolts straight on and the master and caliper pistons are the same diameter so the ratios are all OK.

The 604 hubs are the same but they have larger diameter studs (but with same spline diameter). You can either knock the big studs out and fit the 505 studs or you can just swap the 604 disc onto the 505 hub, which is porbably the easiest seeing as (from memory) you have to take the disc off anyway even if you decide to change the studs.

Dave

 

[Haakon]

Cool! Thanks for that. I suspected as much, but it pays to check I have always thought that all the 504/505s should have had vented discs, as I have found its relativly easy to stress out the solid ones (especialy when they are only 10.4 mm thick ).
Having said that, is it likely to improve the general everyday performance of the brakes - ie feel and bite?