Does your splitter valve come from the same car as the master cylinder? Are both parts suitable for a Disc/drum configuration?

I had a 180B M/C and a Toyota splitter valve (I liked the warning switch on it), but it never worked properly. I used the uglier 180B splitter valve and it started working perfectly.

When brakes bind up like that, it's because the master cylinder is acting like a pump, it sounds like the master cylinder might need a rebuild. This should be done every 10 years I find. Especially if it's come from a wrecking yard (where no fluid is left in it for ages). The master cylinder get Aluminium Oxide buildup, which can cut the seals inside the M/C.

1. Make sure that the M/C and splitter match
2. Go buy a reconditioning kit for your master cylinder from Repco/AutoPro..

Chris