Slave Cylinders

Would anyone know the pipe inlet size of the P6 slave and also the SD1 slave?

I think they are different and an adapter may be required


Well-Known Member
SD1 will be metric, probably m10. P6 is probably same as a bleed nipple, 7/16-20 or 3/8-24. Some master/cyls have an inlet of 3/8 and an outlet of 7/16 so you cant connect things wrongly. why swap to SD1 when early Landy slaves will fit and are cheap? Then you can stay with the P6 hose fittings. Thats my plan anyway. Check in the threads about LT77 conversions. Landy S2, 2a use same part no as P6, 266694.
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Well-Known Member
Whats the connection between a query on thread size of a slave, and the bore? who is 'you' in your last post? Unless the clutch is a much heavier load than before, why a bigger bore? That would mean a longer stroke on the master cyl.
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Well-Known Member
You said "I think you require a larger bore slave. " -who/what does this relate to ? None of the LT77 conversion stuff I have read indicates a larger bore slave is needed.
I answered your question -P6 slave will be 3/8-24 thread, SD1 will be M10 thread.
Thanks. I did think they were the sizes.

I've been listening to several people saying the LT77 conversion will only work with a SD1 slave. I guess not everyone knows.

I'll leave the P6 slave in place then.


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AFAIK you need a P6 master and an SD1 slave, the latter having a metric thread. That's what I used, but I was changing from an auto to the manual...


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SD1 master cyl bore 0.625" (5/8) slave 0.875" (7/8) area ratio 1.96
P6 0.7" 0.875" area ratio 1.5625

P6 slave free travel is listed as 20mm,in which case the master piston must move 31.2mm. dont know P6B throwout leverage - anybody?
If same slave on an LT77 moves 20mm, the master piston must move 39.2mm. Exedy (clutch maker) say its clutch fingers should only move 9mm to disengage, which means (allowing for the leverage) the slave piston should only move 13mm. fitting an SD1 master will go close to this.

So, the SD1 will have a lighter pedal assuming the clutch load is similar, but longer travel. The solution if the difference in pedal load is an issue is to fit a 0.625 bore master cyl. These are easily found with the same threads, cheap.
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i can now confirm that the SD1 clutch slave inlet thread size is M12 x 1mm. The bleed nipple is 10mm.

When looking at the P6 slave on the car, it is leaking. So i have come up with an idea on how to get around this. I'll put it on my build thread.
Resolved. In the end i went for the SD1 slave as the P6 one looked old. The way i worked around it was to use a TR7 clutch slave pipe. It is £13 new.

It comes with M12 x 1mm fitting either end. As mentioned above, the SD1 slave is a M12 x 1mm inlet fitting. What i did was cut off one of the M12 fittings and replaced it with a 3/8UNF fitting for the P6 slave cylinder. I then re-flared the pipe to suit. I have left a couple of inches incase i need to 'lose' a little pipe.

SD1 slave.jpg

job done.