roller Posted September 19, 2006 Share Posted September 19, 2006 should i upgrade to the 15/16 mc? i did buy the stainless braided front lines. i'm running stock calipers. Quote Link to comment Share on other sites More sharing options...
Miles Posted September 22, 2006 Share Posted September 22, 2006 No you don't need the 15/16 MC unless you are planning on installing the toyota 4x4 calipers or you want to pay less for a new MC ($90.00 vs $140.00). I installed the 15/16 280zx MC before I switched to the Toyota setup. With the stock calipers it will take a little more foot pressure on the brake. You will also have to adjust the master vac push rod out a little longer since the 280zx MC is deeper where the push rod contacts the piston in the MC. There are several write ups you can search for here in the brake section explaining the pros and cons of installing a 1979 280zx MC in a 240z. Miles Quote Link to comment Share on other sites More sharing options...
roller Posted September 22, 2006 Author Share Posted September 22, 2006 how much firmer are we talking? Quote Link to comment Share on other sites More sharing options...
Miles Posted September 23, 2006 Share Posted September 23, 2006 With the Toyota 4 x 4 claipers and 79 280zx MC in place, properly bled, and pushrod adjusted you have to push a little harder on the pedal , not much, but it is noticable. The Toyota 4 x 4 calipers eliminated the brake fade I used to experience making just one hard stop, such as, a red light or car stopped in front of me with no warning. It used to get scary. Fade is much less in those situations. I noticed that when applying the brakes the first time that the car slowed down faster and the nose of the car pitched down like the brakes were working like they were supposed to. The rear brakes have never seemed to do much even with all new parts. You will notice that the pedal travels more, even with the ZX MC extra volume, but that results in a feeling of more modulation. In emergency stops the car nose plows down hard and stops where I want it to even though the pedal feels like it has more travel. To some degree the push rod adjustment will take out some of the long pedal action, but you have to be carefull not to adjust it out too far or the brakes will lock up due to fluid being trapped in the system (long story do a search). I just adjusted the rod out, test drove the car in front of my house , and the brakes locked meaning the rod was out too far. If the brakes lock up you simply take a 10mm wrench and open the MC bleeder screws to relieve the pressure and then carefully drive home. Keep readjusting and test driving in a safe place until you get the pedal feel you want. The push rod can be adjusted with the MC hardlines in place, just unbolt the MC and push it out of the way. The push rod adjusting nut is 7mm and you will need vicegrips to hold the rod while you adjust the nut. You can bend the Datsun hard bridge tubes to fit the Toyota calipers. It was the most time consuming part of the install because you have to be careful not to kink the hard line. You can get longer steel braided lines and eliminate the bridge tubes. DO NOT use banjo fittings on the Toyota calipers as the spot they mount to are not milled for bajo fittings and they will leak. Instead, get stainless lines that screw into the caliper like the original Datsun bridge tubes. Get stainless lines with a 90 deg angle fitting where it goes into the caliper. The toyota calipers are available at Napa p/n 442-6648 and 442-6649 loaded about $300 including core charge. To make this swap work properly bench bleed the ZX MC and the system after installing the Toyota calipers. After years of frustration bleeding Datsun brakes I bought a power bleeder for this job and it worked well. Be sure your booster works and the push rod is adjusted to where it just touches the MC piston. There is an excellent wright up in the Brakes section with photos and measurements for the push rod adjustment. Miles Quote Link to comment Share on other sites More sharing options...
roller Posted September 23, 2006 Author Share Posted September 23, 2006 that a lot of good info you just gave me. thanks. i do have the stainless lines but they have straight ends on them can i still use them to get rid of the bridge lines or do i have to have the 90's? also i wonder how far i have to let the pushrod go in the mc? the reason is this is a street/drag car and i had a guy make an adapter plate out of .750 alum. to eliminate the booster all together so i'm kinda fabing from scratch. Quote Link to comment Share on other sites More sharing options...
Miles Posted September 23, 2006 Share Posted September 23, 2006 The straight ends should work. No booster...just adjust the rod until it just touched the MC piston. Quote Link to comment Share on other sites More sharing options...
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