Calling all 'real' rotus owners.... brake master cyl sizes

[ptegler]

what are your master cyl size?  Mine have  5/8 cast right in the bodies on top, just forward of the reservoirs. I ask as my fresh brake rebuild, all new hardlines, flex lines, calipers... but it seems my pedal stroke is more than expected.  So I'm wondering if I should go to a larger cyl bore to shorten the throw.
comments? flames? useful context?

tia

ptegler

 

[MV8]

Larger bore will provider a firmer pedal as well, but higher effort to stop. I'd try 3/4" but keep the old one.

[ptegler]

3/4" was my next step/thought. I've done a ton of Triumph Spitfires, roughly the same size vehicle, but normally closer to .7" for the dual master.
This car came with a Tilton pedal assy with oem Toyota  5/8" cyls. (x3)  I'm assuming the twin brake masters were just 'cool' and an easy way to deal with front/rear brake bias balance when playing roulette on which front and rear calipers were used.  The Spit with front disk and rear drums, are matched pretty and use a single dual master cyl on the Spit. I've upgraded Spits to the larger rear drums of the late GT6 MKIII wit no ill effects. So I have to assume there is a bit of forgiveness built in.   I like the Tilton assy since the seat doesn't move you move the pedals closer to the driver as needed. But it leaves a lot of open holes for engine compartment heat/gas/smells to come through, where if I swapped to the Spit set up, I could seal up pretty well. That route would also leave me with common spare parts supply.  (which I have of Triumph stuff)

tnx for the input @mv8

ptegler

Edited October 23, 2023 by ptegler