1979 XS400 rear master cylinder compatability

[killsurfpsych]

I just bought a 79 xs400. It's my first bike and this is my first forum post and I'm a total rookie at all of this.

The bike has no rear master cylinder. I've been searching all over for one from a 79, but could only find one for an 80 xs400. Does anyone know if this would work? If not, any recomendations on other options I could excersize? Although I'm not a motorcycle expert, I'm almost certain I'd prefer to have both brakes be fully operational

Thanks!

 

[Charles]

I didn't think 1980 XS400s came with rear discs. It's possible it's mislabeled. Given that the caliper from the 79 XS400 is the same on virtually every other XS bike (650, 750, 850, etc), I'd imagine the actual master cylinder would be too.

But for an exact match looks like the 77, 78, and 79 XS400 brake setups are the same
http://www.boats.net/parts/detail/yamaha/Y-1U4-25850-51-00.html