GIchiro Posted April 4, 2017 Share Posted April 4, 2017 So I have modified a Z31 dual-diaphragm booster and also bought the MC. -The MC has 2 outlets though for the front brakes. -Can I plug one of the outlets? OR -Do I need to plumb lines separately to the front calipers? Currently I have: Toyota 4 pistons up front Mustang calipers rear Thanks, GI Quote Link to comment Share on other sites More sharing options...
Miles Posted April 4, 2017 Share Posted April 4, 2017 Does your MC look like this? What diameter piston does it have? You do know that it is a fast fill MC. See the bulge on the side. Has to do with reducing pad drag on the rotors by using "low drag calipers". Google what a "fast fill MC" is. With your particular caliper combination you would need a 15/16in. to 1in. diameter MC to flow enough fluid. Search the brake and FAQ forums to see if another member has used this MC. Opinion: Why would you do all of the unnecessary plumbing when tried and true bolt on solutions are available. Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 4, 2017 Author Share Posted April 4, 2017 It is a 15/16 bore MC. -If the MC is not recommended, can I use the 280zx MC with Z31 booster. - I have a ZX MC but thought the dual diaphragm would brake the car better since it will have a 3.0 liter in it. -I just need to know if I can plug the one outlet and run the one to the 240Z prop valve Thanks, GI Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 9, 2017 Author Share Posted April 9, 2017 -I read up on the "fast fill MC aka Quick uptake MC". - It does not say you can use a non-low drag caliper with a fast fill MC. -But, it did say you cannot use low drag caliper with a regular MC. -So my question is: -Can I block off one of the front caliper ports, since it has 2 for the front, and run it with regular calipers? Thanks, GI Quote Link to comment Share on other sites More sharing options...
Miles Posted April 9, 2017 Share Posted April 9, 2017 The only member I recall doing something like this is Tooquick260. You might PM him or google "Tooquick260" If you do plug the outlet use a plug made for inverted flair M10 x 1.0. Quote Link to comment Share on other sites More sharing options...
98blackbell Posted April 9, 2017 Share Posted April 9, 2017 We did the Z32 mastercylinder and booster, as well as the z32 front and year brakes.. We drove it for about 2500 miles and a couple events. The booster from the z32 over powered the breaks and made them very touchy. Hard to modulate. Had to go back to the stock booster and m/c. Seems the S30 is a lot lighter and does not need the over boost. The z31 may be ok. You can only try and see. The z32 booster is bigger. Do you have a comparison in booster size. Quote Link to comment Share on other sites More sharing options...
98blackbell Posted April 9, 2017 Share Posted April 9, 2017 Comparison, s30 left and z32 right. Quote Link to comment Share on other sites More sharing options...
Miles Posted April 10, 2017 Share Posted April 10, 2017 (edited) A one inch Wilwood MC paired with a 280Z booster is what I am using with the Toyota - 240SX combination. Pedal is not stiff. Just feels like normal power brakes. Originally used a 280ZX MC with stock 240Z booster, but the pedal was too stiff. There are several posts here and at ClassicZcars.com describing the 280Z booster swap. Edited April 10, 2017 by Miles Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 11, 2017 Author Share Posted April 11, 2017 The Z31 booster is the same diameter as the 73 z, just dual diaphragm. I hesitate with wilwood product quality is why I haven't looked at their 1" MC. Thank you, GI Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 15, 2017 Author Share Posted April 15, 2017 So I have the 15/16" ZX MC mated up to the Z31 booster but the BB to MC pin seems a bit short. I usually run .020" clearance but with the original MC spacer/mount I am not even close. Does anyone make a longer rod that is adjustable? Thanks, GI Quote Link to comment Share on other sites More sharing options...
Miles Posted April 15, 2017 Share Posted April 15, 2017 Did the reaction disk fall into the booster? Quote Link to comment Share on other sites More sharing options...
NewZed Posted April 15, 2017 Share Posted April 15, 2017 -So my question is: -Can I block off one of the front caliper ports, since it has 2 for the front, and run it with regular calipers? Thanks, GI It's gotta be two ports just to handle the fluid volume that the calipers use. Blocking a port should work. But, as noted, you're kind of reinventing one of many wheels. Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 16, 2017 Author Share Posted April 16, 2017 NewZed, -that makes sense about the amount of fluid for the calipers. -I am extending the booster to MC pin since the 240z booster spacer make the MC sit too far out. -I will post some pics soon. Thanks, GI Quote Link to comment Share on other sites More sharing options...
GIchiro Posted April 27, 2017 Author Share Posted April 27, 2017 What if I run lines directly to the front calipers and plug off the prop. valve at those three sites and run a line from the MC rear port to the prop. valve rear inlet? GI Quote Link to comment Share on other sites More sharing options...
Miles Posted April 27, 2017 Share Posted April 27, 2017 Because Z brake systems changed year to year, you need to tell us what year Z you have. Post some pictures of what you are calling a "proportioning valve" would help. Quote Link to comment Share on other sites More sharing options...
GIchiro Posted May 10, 2017 Author Share Posted May 10, 2017 I have a 1973 with the wheel well mounted prop valve and then firewall mounted that feeds passenger front brake and rear brakes. I have been able to mount the stock 15/16 ZX booster to the Z31 brake booster. I made new lines for that. I did by an adj. prop valve. -Is the firewall mounted proportioning valve a "damper" device of some sort. I do not know why there would be 2 proportioning valves. I did take it apart and cleaned it (wow was it nasty, both of them actually). Thanks, GI Quote Link to comment Share on other sites More sharing options...
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