[TR] TR4 vs 4A clutch piping

[Peter Caldwell]

Cognescenti listerati,

	I have a customer who is needing to re-plumb his clutch hydraulics. 
His car is a TR4, as we've determined through the years. It seems 
that what is on the car, though is 4A stuff. (lots of it)

	Using various original TR manuals, and Moss, et. al., it seems that;

	 4s used 3/16 tubing and a rubber flex hose at the slave. The 
fittings would have been a 3/8-24 male single(bubble) flare into the 
master, a length of 3/16 tube, a 3/8-24 female nut single flare, 
rubber hose with a long 3/8-24 male fitting to accommodate a nut for 
a bracket. rubber hose (8") with a 3/8-24 straight fitting requiring 
a copper gasket at the slave.

Whereas
	4As used 1/4" tubing and a stiffer kind of flex tubing a la 6s at the slave.

	Both use the same master cylinders, and hence bore diameters.

	My questions are:  1) am I correct in the above?
			
			2) In other cars, when the line diameter changes from 3/16 to 1/4 
there is a concurrent change in bore diameters of either the master, 
or the slave, or both.   Why not with the 4A, and are there 
advantages of 1 plumbing scheme over the other.

	We are thinking that while this car has many parts of both 4s and 
4As, that it would be best to make it as much a true 4 as possible, 
unless there is a compelling reason to switch to 4A clutch piping.	Pedal feel?


	Thanks for any help.

Peter C.