Dredging up an old thread so the information stays in the same spot.
 
I'm looking at doing the Datsun 120Y conversion on my Mk1 Escort and would like some clarification if possible.
 
I'm about to purchase a JB117 master cylinder to suit a 120Y, as this is the correct one from all that I have read but I'm not sure which one to get:
 
 
 
 Does anyone know what differences exist between the 3, if any, and which is the correct one for the conversion? 
 

martymexico
Many people use a non boosted Datsun 120y master cylinder(new on eBay $110) with a 180b or 200b adapter, this works well on std brake setup...

 
Does anyone know what the 180B or 200B adapter is as mentioned above by martymexico? I'm aware I need to make an adapter between the master cylinder and firewall but I have no idea what the 180B or 200B adapter is.
 
Thanks.
 
Chuff

Hi Chuff, I fitted a datsun 11/16 m/c from maddat. Original plan was without booster but engineer would not allow, so I fitted booster under fender. Pedal pressure is a bit soft but stops well. I think without booster will be fine. I made up my my own adapter with adjustable rod, hope this helps, cheers Peter.   

I’ve done the 120y setup To my 72 mk1z
But I don’t find the pedal and rod sitting properly in the MC, and therefor lots of play with the brake pedal and the pedal sits really high. Does anyone have any ideas on how to 1. Adjust the pedal
2. Ensure the rod stays in the MC?
Thanks all

I cannot remember how I done mine years ago but the mk1 has a threaded rod from the pedal, this can used /cut/welded and adapted to fit snug in the mc , word of warning about welding rods for brakes, if you can't weld get someone who can as you don't want the rod fatigue and crack in use . As for mc to bulkhead adapter it just converts the horizontal escort stud pattern to vertical (Datsun) or make one from a chunk of 15 to 20mm thick alloy plate , I did this to the Ford laser mc to escort (hotrod) vac booster it all looks normal and works well