Recently swapped rear discs into a car that had drum brakes in the back. Purchased a junkyard brake master cylinder from a rear disc brake car but one of the fittings in the disc brake master cylinder has a larger m12x1.0 inverted vs. the m10x1.0 inverted that was on the vehicle. So i scrapped that idea and decided to purchase an inline adjustable proportioning valve which seems to be a bit of work; but, is it worth it in the end? I haven't had the opportunity to drive the car yet which I might tomorrow...just looking for opinions.
Discs need a bigger reservoir I think. You probably need a reservoir and master from a disc brake car and an adjustable prop valve for fine tuning.
what kind of a car are we dealing with here?
when i put the rear disc rear end out of an '02 Z28 under my 86 Camaro a couple of months ago, i also got the master cylinder from the same car as the rear end.. the rear brakes did nothing with the stock proportioning valve, so i took the spring out of it and suddenly i had too much rear brake... so i put a $38 Wilwood adjustable prop valve in the rear line just after the stock prop valve and got it tuned to "just right".. it took me about an hour to put the Wilwood valve inline, but that was only because i had to redo a flare because i did this on one line:
Most importantly, you need to get rid of the residual pressure valve, which is most likely part of the master cylinder. You want the master and prop valve and the lines between the two, then adapt whatever fittings you need to make it work.
Adjustable prop valve can certainly do the job, too.
Streetwise has it right. The residual pressure valve is a much bigger issue.
On the ZX2 sight, there as a lot of rear disc swapping and a lot of rhetoric about master cylinders and proportioning valves.
General opinion was that it didn't make much difference.
Why not just adapt a fitting to make the correct MC work?
