Okay, now that I've already routed it...can the steel brake line supplying fluid to the front brakes be mounted ABOVE the master cylinder at any point in it's wandering journey from "T" fitting to caliper? (I ran the one for the passenger's side along the top of the firewall for lack of a better way to go...master cylinder and booster are firewall mounted now). Half of me thinks that the master cylinder should be the highest point in the system, and the other half thinks the first half thinks too much...who's right?
Your not suppose to, when the master is not the highest part of the hydraulic system you have to run a residual valve to keep the fluid from draining back into the master cylinder. I just plumbed the brake system on the roadster and had to run two of them cause the master is under the floor.
I have a master under the floor of my 50 Chevy Pickup without residual valves. I haven't had problems with mine but thats not to say someone else wouldn't.
Hey Hack, Residual check/pressure valve. Check here for more info: http://www.wilwood.com/products/master_cylinders/rpv/rpv.asp
yeah , just use the residual valves inline and not worry about it.....most hot rods have the master cylinder under the floor ,so at some point the brake line will be above it
Every rod built with the master cyl under the floor and the wheel cyls at the top of the backing plates has the same problem you have. No biggie. Run the residual valves and you'll be fine.
I've also heard that some master cylinders have residual valves built into them, and ther's away to check it, but don't remember how.
A master cylinder that was made for drum brakes, before proportioning valves, will have a residual pressure valve in it already. It's necessary so the brake return springs don't retract the shoes too far back from the drums. A master that was made for disc/drum, with a proportioning valve, doesn't have one, though the proportioning valve may have one built in. on the drum side. The disc side won't have anything, so if you've got discs up front, with a lower master, you need a residual pressure valve in that line.
not to highjack a post, but will a residual pressure valve "close off" the line behind it if there is a blow out in the line? a current daily driver project that i am putting together has a boosted single cylinder deal on it, and i'd like some more security than just the "one line wonder." if a residual check valve won't close off the line following it after a blow out, what exactly is it that does??
Yep, residual valve would be a good idea. If the line goes up and then back down it may be hard to bleed. Air tends to collect in those spots.
Before I installed the master cylinder in my car I took the check valve out of the master cylinder to prevent the front brakes from locking up. I was running a 5 pound residual valve in the front and a 10 lb to the back. I am running front disk and rear drum and an early chevy master cylinder. The master cylinder is below the floor board and below the brake lines. It stop pretty good. I hope this helps. Slick Willie
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