Posted by T.L. (209.254.240.67) on April 10, 2001 at 20:36:16:
In Reply to: Junction block/Prop Valve posted by rickyracer on April 09, 2001 at 22:24:38:
Most of what you said is true, however it does NOT take "longer" for the fluid pressure to reach the rear brakes because there is (supposed to be) no air in the system and fluid does not compress...makes no difference if it's 2 feet or 10 feet with hard lines. It would make a huge difference if the lines were flexible...then there WOULD be a lag time. Also, the JUNCTION BLOCK has no springs in it...it's only purpose is to connect all the lines to the corresponding brakes...
: Brake systems are very misunderstood. Junction block only distrubutes the fluid to all connections. Since front brakes are closer and each have their own line they get more & fluid faster. Rear takes longer and spits cutting the pressure & volume in half.
: Disc brakes use a proportioning valve which has a differenial spring in it to control fluid flow to the closer but larger front disc caliber pistons. There by they get pressure first until it reachs a certian presure, Preset point depending on the spring, then the fluid starts to move toward the rear brakes. That's the real difference required for disc vice drum front brakes.
: Also remember that disc brakes use a clamping action and drum use a expanding action. Different braking methods. Drums work better when stopped to remain stopped and disc stop you quicker and better. Next week we'll talk Hydraulics 102.
: : Well I didn't mean for y'all to go at each other that way. But we did get some pretty interesting things going on. :-) Thanks for the help Gentlemen. I changed the junction block. I'll let you know how well it works when I get it done. By the way, my Son drives this car, I can't take any chances :-)
: : Thanks again
: : Willy