Bartman Posted November 18, 2004 Share Posted November 18, 2004 I'm putting Toyota 4-piston calipers with vented rotors on the front and disk brakes on the rear of my 1973 240Z. It will primarily be used on the street, but I would like to be able to take it to the track now and then. My question's are: Should I remove both of the existing mixing/proportioning valves and replace them with one aftermarket proportioning valve? Should I replace the brake master cylinder and/or booster? Whatever I need to replace, let me know what you think I should replace it with. The build tally is growing fast, so a cost effective solution is preferred. As always, any advice is appreciated. Quote Link to comment Share on other sites More sharing options...
2126 Posted November 18, 2004 Share Posted November 18, 2004 Don't use the search function what ever you do! Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 18, 2004 Author Share Posted November 18, 2004 Don't use the search function what ever you do! Before I posted I used the search function and I've found some information about upgrading to later model Z or ZX 15/16" master cylinders, and about proportioning valves. My question is pretty specific in regards to my vehicle and how I intend to use it. In what I read it appears removing the existing valves is still questionable depending on the year of the vehicle. Also things change over time, and there may be better solutions now. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted November 18, 2004 Share Posted November 18, 2004 I don't believe there is any performance difference between any of the years of the S30 in regards to the brakes. Generally, any upgrade that includes larger than OEM caliper pistons will require a larger MC to keep the ratios correct at the pedal. An aftermarket proportioning valve is recommended (IMHO) due to differences in the effects of drum verses caliper brakes using the same fluid pressures. I did remove any OEM valving first before installing the adjustable valve. Quote Link to comment Share on other sites More sharing options...
auxilary Posted November 18, 2004 Share Posted November 18, 2004 70-72 240zs had 1 prop valve, 73-74 (not sure about 280) had 2 prop valves. I took both out, and I'm planning on running direct lines to the front brakes, and a prop valve to the rear brakes to control rear pressure. My setup is same as yours: 15/16 mc, 4 pot toyota front, 240sx rear Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 19, 2004 Author Share Posted November 19, 2004 I just purchased a new zx master cylinder from eBay for $60! I was perplexed with my 73 having two proportioning valves, but now I know I can just remove them both and put in one Wilwood proportiong valve. My next task is to make some new brake lines. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted November 19, 2004 Share Posted November 19, 2004 Dude, have you price checked them at your local parts counter....cheaper than $60!!!! Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 19, 2004 Author Share Posted November 19, 2004 Dude, have you price checked them at your local parts counter....cheaper than $60!!!! #$%@! I looked around online and the prices were much higher than $60, but i didn't check my local parts counter. Before I waste more money, where can I get the best deal on a wilwood proportioning valve? They're going for around $35 on eBay. Quote Link to comment Share on other sites More sharing options...
Savage42 Posted November 19, 2004 Share Posted November 19, 2004 That's a fair price for the Wilwood proportioning valve, as they retail for $39.99 at http://www.precisionbrakescompany.com. Quote Link to comment Share on other sites More sharing options...
auxilary Posted November 19, 2004 Share Posted November 19, 2004 i bought my rebuilt 15/16 nabco MC from kragen for $51, and could've gotten 7 back on core refund. Quote Link to comment Share on other sites More sharing options...
Phantom Posted November 19, 2004 Share Posted November 19, 2004 There also has been some discussion about the check valves in the master cylinder for rear drum brake cars vs cars with rear disk brakes. I went to the 79-81Zx master cylinder on my '77 for that reason. I have not yet done anything with the proportioning valve. The set-up I have at this point bias's the braking to the front (12.2" Willwood front with 240SX/300ZX calipers/rotors in the rear). I haven't taken the time to determine if it requires a proportioning valve on the front yet or not. What you do with a proportioning valve is extremely dependent on the specific brakes you install. Quote Link to comment Share on other sites More sharing options...
hanomon Posted November 19, 2004 Share Posted November 19, 2004 Bartman, I'm assuming you have the rotors and pistons for this up-grade? I think the second prop-valve you refered to is in fact the brake-warning switch. If it has a wire to it, then thats what it is. Your prop-vlv is located either on the fire-wall, or above the rear suspension. Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 19, 2004 Author Share Posted November 19, 2004 Bartman, I'm assuming you have the rotors and pistons for this up-grade? Yes, I have everything now but the proportioning valve. Quote Link to comment Share on other sites More sharing options...
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