I have a question; it might be controversial but i still have it. I was reading i think on here and can't find the thread. If you have a modern master cylinder from a mid 80s pickup in an older car do you need to run a proportioning valve? If i recall, there were a few guys saying with 4-wheel disc setup and new master cylinder the prop valve renders its self-useless?? I did a 4-wheel disc setup on my demon and just wondering as I will be doing a line lock and if i can get rid of the prop valve I will.
True or false? and any comments or experience is welcome.
I know I ask a lot of questions i should know the answers to.
A proportioning valve is needed for disc drum systems. It's not required for drum drum or disc disc. It would be beneficial in those cases for fine tuning though.
BTW, that 80s truck MC has 2 problems with disc disc systems. 1 it may have a residual pressure valve, no bueno for disc brakes. 2 the reservoir for the rear brakes is much smaller than typically found on disc brakes, if you keep an eye on fluid levels this isn't a problem.
