Mr P body, i believe your correct, the braided hose you used could have had a less tight braid that allowed alot of expansion of the teflon. its hard to say, thats why i said it was a guess. since you seem to have ruled out the too small master, it may be a matter of finding a better hose supplier.

just and FYI i am a firm believer in steel lines and only to use hose where absolutely necessary for compliance.