Rear Brake Master Cylinder Kit
Location:  NOS 25 / T
1U4-W0042-50


This kit was made for our shop only. We paid the tooling fees so that the company does not feel the need to sell to anyone else. 
Made in Japan, so you know the quality is top notch. 
Buy two kits so that you have a spare one for the future. 


Want to make sure this part fits before you order it?
We will help you confirm fitment and compatibility! Send us a message with your V.I.N. number (usually stamped into the frame), and we will look up your machine to make sure you get the correct parts!

This Item Will Fit The Following Yamaha Models:
1977 XS400D 
1978 XS400E 
1979 XS400F 
1978 SR500E
1979 SR500F 
1978 SR400
1979 SR400
                       *The following European models use this kit when they have rear disk brakes. 
Years unknown XS360 from what I have been told the 1977 XS360-2D Uses this kit. 
Years unknown XS250

This Item Replaces OEM Part Number:
1U4-W0042-50 
1U4-W0042-50-00
1U4W004250
1U4W00425000