172 Brembo master / servo help

[Iamhiding]

Hi guys, wondering if anyone has any insight.

Just finishing up a brembo conversion on my ph2 172 (non cup with abs) and whilst i appreciate you get away with the standard master cylinder i know from experience with building bikes how much difference in feel a master creates. It's not something you can appreciate until you've experimented with hydraulic ratio in both directions i reckon.

Anyway, i was under the impression you can use the 197 master as a straight swap in conjunction with the 172/182 servo. Can anyone verify this?

I'm going about the master situation a little creatively which i'll explain once i've verified it rather than muddy information on here.

Currently, i've thoroughly power bled the system it holds pressure on the bleeders guage, doesn't leak but pedal falls to the floor as if systems open. So either there's a stack up height / stroke issue in relation to servo or the 2nd hand master I've used's seals are gone in spite of basic bench testing. Likely both knowing my luck.

I can refit the 172 master in the meantime whilst i inspect however if i'm upgrading the master... I don't want to do this job a 3rd time so any insight is massively appreciated.

 

[Gus]

Did you let all the brake fluid leak out when putting the Brembos on? Reason I ask is the reason for the soft pedal might be because you need to bleed the ABS too. Some of the better OBD readers have this function and obviously also Renault Clip.

The pedal should only be a little softer compared to what it was like before you put the Brembos on.

No experience with the Master Cylinder swap question though.

 

[Iamhiding]

Alrighty gus,

yeah so i've replaced all 4 calipers and bled them in, pedal had a wee bit more travel than standard at that point. I didn't test drive as no mot / had plans on doing the master anyway.

When doing the master the abs feed lines will have been essentially emptied, doesn't seem like an abs bleed issue as the pedal would still build some pressure after a few pumps but i'm getting nothing like the master seals are gone or the master has a longer throw and therefor the pedal doesn't travel far enough. Pressure bleeder would have gotten enough air out to build some pedal pressure.

Good shout though, i'll give that a bash just to rule it out.