jakesae101 Posted June 29, 2016 Share Posted June 29, 2016 so in my rally car it has a factory dual line proportioning valve so both lines from the master enter the valve and it splits into the 4 wheel lines there , Now i have wanted to add a hydro handbrake as the factory handbrake setup isnt overly robust but with dual lines after the proportioning valve how do I achieve this i know there are a few options , Not so keen to goto a dual cyl hydraulic handbrake as they are quite bulky and they don't make one that has a long enough handle for where i want to mount it , it will be certed on a MSNZ authority card. The options so far from internets research and thinking 1.T the rear lines togeather and pass them through a standard single master in the hydro and then split them again (i don't know is that legal?) 2. use a tandem master with a reservoir like in a standard car and T into each of the rear lines but id need to find something that has equal primary and secondary chambers in it and modify a standard hydro to fit it 3 use a dual piston 4 port master cylinder from willwood or somewhere and make or modify a hydro setup (they are hella expensive ) so os populace any advice / recommendations ect would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
Rookie Posted June 29, 2016 Share Posted June 29, 2016 I would just bin the factory proportioning valve, and get an adjustable one, then run a single rear line through the hydraulic hand brake and then t it afterwards. I don't see any need to keep it factory. Quote Link to comment Share on other sites More sharing options...
jakesae101 Posted June 29, 2016 Author Share Posted June 29, 2016 id have to change around every line in the car for that as the factory valve splits the system diagonally i think , So i could remove it and feed the primary in the master to the front brakes then M/cyl secondary >proportioning valve > Hydro > T to rear lines seems a bit more work than i really wanted to do but i spose there may not be much choice in it anyone know where the best place to get the fittings is ? Quote Link to comment Share on other sites More sharing options...
Nominal Posted June 29, 2016 Share Posted June 29, 2016 I get my brake bits from ABC in Martin Square in Wellington. Quote Link to comment Share on other sites More sharing options...
Valiant Posted June 29, 2016 Share Posted June 29, 2016 Is it a disc brake rear end? If it is you could add a couple of extra calipers to the rear and plumb it separately. Quote Link to comment Share on other sites More sharing options...
jakesae101 Posted June 29, 2016 Author Share Posted June 29, 2016 nope drums all the way on the rear the other complication is id also have to install a residual pressure valve in there somewhere for the dums as it has to be in the prop valve if they are split diagonally Quote Link to comment Share on other sites More sharing options...
KKtrips Posted June 29, 2016 Share Posted June 29, 2016 Not sure on how your setup is or what car you are talking about but be aware that your system could be a diagonal split brake system - as in the left front and right rear are on the same circuit and vice versa. (this is always the setup on FWD vehicles and often the case when both m/cyl. lines feed into the same proportioning valve and each wheel is output on a separate circuit) Quote Link to comment Share on other sites More sharing options...
jakesae101 Posted June 29, 2016 Author Share Posted June 29, 2016 Not sure on how your setup is or what car you are talking about but be aware that your system could be a diagonal split brake system - as in the left front and right rear are on the same circuit and vice versa. (this is always the setup on FWD vehicles and often the case when both m/cyl. lines feed into the same proportioning valve and each wheel is output on a separate circuit) internets says yes they are in the early mazda 323s and that would make sense why they are all fed through the prop valve Quote Link to comment Share on other sites More sharing options...
KKtrips Posted June 29, 2016 Share Posted June 29, 2016 Quote Link to comment Share on other sites More sharing options...
KKtrips Posted June 29, 2016 Share Posted June 29, 2016 So you would need to avoid diagonally split and ditch the proportioning valve then go through the science of figuring out a m/cyl with the correct dual bore and re-run the brake lines. The front brake circuit would be off the the same bore of the m/cyl and the rear circuit would come off the other half which would run a single brake line to the hydraulic handbrake with a T- split after going to each rear wheel Quote Link to comment Share on other sites More sharing options...
jakesae101 Posted June 29, 2016 Author Share Posted June 29, 2016 bugger might just get a dual cyl cyl and tap each line then Quote Link to comment Share on other sites More sharing options...
jakesae101 Posted June 29, 2016 Author Share Posted June 29, 2016 ala Quote Link to comment Share on other sites More sharing options...
sr2 Posted June 30, 2016 Share Posted June 30, 2016 Mate, sounds like a great project but you're rapidly painting yourself into a corner. My feeling is that you're delaying the inevitable which is simply fitting a dual master cylinder, adjustable balance bar pedal box. I'm ex the automotive brake industry (worked for PBR in Aussie and APPCO Brake & Clutch in NZ)and have been building race/rally cars for the last 20+ years, all I can say is there is a reason why all low tech (i.e. non traction controll/abs) rally cars run this setup. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.