Triumph TR5-250 Clutch Master Cylinder - 6 Cylinder
The TR5, TR250 master cylinders were continued unchanged well into TR6 production. However on later TR6s, the bore of the clutch master cylinder assembly changed from 3/4” (0.75) to 7/10” (0.70). The change very effectively lightened the clutch pedal load. The downside was that it aggravated the problem of insufficient clutch clearance on a mechanism that was worn or had a broken tapered pin in the cross shaft. The later, smaller bore diameter master cylinders may be used to replace earlier types but the above comment must be taken into account if doing so.
If a repair kit is required, before placing an order the cylinder bore diameter must obviously be identified (don’t assume because you have an earlier 6 cylinder TR that you have an earlier cylinder fitted). This is simply achieved by reading the size off the exterior of the cylinder.