yem73z Posted April 30, 2011 Share Posted April 30, 2011 So i've been searching through dozens of threads here on hybridz and ratsun.org and can't figure out how to run my new brake lines. Here are a few details of my set up so far...My car is a 1973 240z and I'm swapping in a vq35de motor with mckinney motorsport mounts and r230 rear diff. The whole entire rear suspension is techno toy tuning's 5-lug swap set up using the z32 calipers and custom chromoly cv axles. The rear diff is mounted with techno toy tuning's r230 rear diff swap mount and I Also have the rear lower control arms and billet aluminum mustache bar as well. For the front i have Arizona Z car's 5-lug swap with wilwood calipers. I have a few of the pics in the 6 cylinder forum to better illustrate my build so far. But anyhow back to the question at hand...I bought 25ft of stainless 3/16 hardline and would like to run brand new lines. My main issue is that the rear parking brake mechanism that is used with the z32 hubs/calipers. The 1993 z32 300zx turbo parking brake mechanism that im using is a sort of inner shoe design to work by expanding and thus making contact with the inside of the rotor hat once you pull on the mechanical hand brake line. I don't want to deal with custom fab work at this point trying to make that work since it's only going to serve the parking function. I've come to the conclusion that I want a hydraulic line lock for parking instead. I know Arizona Z car sells them along with the wilwood adjustable proportioning valve and i just want to know where to plump it in the brake system. So I drew up a rough sketch of how i might set this up, but Im new to brake systems and i would like your advice on where to put everything. Please correct any problems you might notice in my diagram and educate me on where to place things appropriately. Quote Link to comment Share on other sites More sharing options...
yem73z Posted April 30, 2011 Author Share Posted April 30, 2011 And if anyone is wondering why im using the r230 out of a 93 300zx turbo, its because it is strong, ratio is close to the 350z diff and most importantly it has the abs rings with the same diameter and teeth count as the differential off of a 350z and would provide me with a speedo reading. Quote Link to comment Share on other sites More sharing options...
Nigel Posted April 30, 2011 Share Posted April 30, 2011 A friend of mine has Arizona Z car brakes on the front and rear of his 280ZX, with a line lock on the rear brakes. If he leaves the car overnight, or any extended length of time, with the lock on, the brakes wont release. I don't know if this is a common problem with using a line lock as a parking brake or not. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
dsommer Posted April 30, 2011 Share Posted April 30, 2011 I bought a kit off ebay that has sections of hard line that need to be bent. It was <$50. I would recomend getting this set up as #1 I don't think 25' of brake line is going to be quite enough (might be wrong) #2 the ends of what I bought are alredy flaired and have the proper metric fittings on them. They are in various length sections and you'll need a tube bender. I haven't started on mine yet but fwiw making all those double flairs is a PITA. My link Quote Link to comment Share on other sites More sharing options...
twofouroh Posted April 30, 2011 Share Posted April 30, 2011 Just my 2 cents, but I would never put in the effort of an entire custom bent setup on anything but stainless. I know stainless is a pain to flare, but it's forever. Wonder if there are still any hard line shops around that make a stainless hard line set for the early 74 260 . . . Quote Link to comment Share on other sites More sharing options...
papa721 Posted April 30, 2011 Share Posted April 30, 2011 what is the total length of those techno toy tuning rear coil overs?.... with the shock in place and evrything from top to bottom what's the length.... btw.... super nice build u got going on Quote Link to comment Share on other sites More sharing options...
yem73z Posted May 1, 2011 Author Share Posted May 1, 2011 i havent put the rear coilovers on yet. when i get a chance, i'll take measurments and pics. However, can anyone give me more advice on my brake line diagram? is everything where it should be? should i put the adjustable prop. valve in the engine bay as factory has it? any advice would help, since this is my first time doing brake lines. Quote Link to comment Share on other sites More sharing options...
bodie Posted May 2, 2011 Share Posted May 2, 2011 im workin right not on making the 300zx parkin brake setup work, using the 300zx cable and just fabbin a cable mount and balance bar. its looks very doable. Quote Link to comment Share on other sites More sharing options...
bodie Posted May 2, 2011 Share Posted May 2, 2011 btw id run the line the say way as oe if space permitted and get ride of the combintion valve. Quote Link to comment Share on other sites More sharing options...
dsommer Posted May 14, 2011 Share Posted May 14, 2011 Looking at your diagram, I believe there is a stock proportioning valve prior to the rear T fitting. Also on your front diagram the inlet would be the bottom of the T, not the side.(you probably knew that though). Also there is some type of manifold proportioning valve just after the master cylinder. Look at some stock set ups and you'll see what I'm talking about. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 14, 2011 Share Posted May 14, 2011 (edited) A friend of mine has Arizona Z car brakes on the front and rear of his 280ZX, with a line lock on the rear brakes. If he leaves the car overnight, or any extended length of time, with the lock on, the brakes wont release. I don't know if this is a common problem with using a line lock as a parking brake or not. A guess at the cause might be that he puts the brakes on at night, then the fluid expands when the sun comes up, so now he has the brakes on REALLY hard, and it's hard to release. If possible, might suggest he tries putting them on very lightly. That's a SWAG. For the OP, I think my plumbing came out pretty friggin awesome. I had removed all the fuel lines and brake lines and cut the fittings off of the chassis, so I really was starting from scratch. I was looking at the stock fittings and the brake lines curving under the frame rails, etc, and didn't like it, instead I used bulkhead fittings through the fenders. I did delete the prop valve in the car, so now the line that goes to the rear brakes just goes straight down the trans tunnel. Your's would obviously be a little different because you don't have dual masters, but I think the actual brake setup is pretty similar. I used AN fittings throughout, I think that's a good idea because AN fittings are easier to deal with than double flares. I've done lots of double flares before, so I can say this having experience with both. I used cheapo brake line from Summit and bent it mostly by hand even though I do have a couple of benders. I had to buy another coil of line to remove the prop valve, and I bought that at the local NAPA. The stuff from NAPA was much harder to flare without splitting. I think if I were going to do it again, I'd do cupronickel hard lines. It's supposed to be the easiest to work with. FWIW your sketch looks fine in terms of placement of the prop valve and the line lock, etc. Edited May 14, 2011 by JMortensen Quote Link to comment Share on other sites More sharing options...
Nigel Posted May 14, 2011 Share Posted May 14, 2011 A guess at the cause might be that he puts the brakes on at night, then the fluid expands when the sun comes up, so now he has the brakes on REALLY hard, and it's hard to release. If possible, might suggest he tries putting them on very lightly. That's a SWAG. He never said anything about the linelock being difficult to release, so I don't think that's the issue. I think what is happening is that ordinarily, when you apply the brakes, the caliper piston doesn' t slide in the seal, but rather, the seal flexes. But if you apply the brakes and leave them pressurized, the seal relaxes with the piston extended out. So, now the seal is holding the piston out and causing the brakes to drag. My buddy was telling me that he'd have to rock the car back and forth to get the brakes to free up. Looking at your diagram, I believe there is a stock proportioning valve prior to the rear T fitting. Also on your front diagram the inlet would be the bottom of the T, not the side.(you probably knew that though). Also there is some type of manifold proportioning valve just after the master cylinder. Look at some stock set ups and you'll see what I'm talking about. Why would it matter if the inlet to the T were on the side or bottom? Also, you mention 2 proportioning valves. There's only one prop valve in a Z (near the rear brakes on 70-72 Z's, and on the firewall on 73 and later Z's). What's the manifold proportioning valve that you're referring to? There is a brake pressure differential warning switch on the driver's side inner fender. Is that what you're talking about? According to his diagram, it looks like yem73z has removed that warning switch, and replaced it with the T. On a '73 240Z, the prop valve uses brake pressure to the front right caliper to modulate pressure to the rear brakes. Yem73z has correctly shown the OEM prop valve removed, with the front right brake line going directly to the front right caliper now, and the new adjustable prop valve in-line with the rear brakes. The adjustable valve can go in the cockpit or engine bay. It doesn't make any difference as far as function is concerned. Obviously it's going to be easier to adjust from the cockpit, so long as you can trust your passengers not to fiddle with it. The only issue I see with the diagram, other than the concern I raised earlier about the linelock, is that you show the front reservoir connecting the the front brakes and the rear reservoir connecting to the rear. This should be reversed. Only the early Z's (pre '71 or '72) had the front reservoir connected to the front calipers, and rear to rear. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 14, 2011 Share Posted May 14, 2011 He never said anything about the linelock being difficult to release, so I don't think that's the issue. I think what is happening is that ordinarily, when you apply the brakes, the caliper piston doesn' t slide in the seal, but rather, the seal flexes. But if you apply the brakes and leave them pressurized, the seal relaxes with the piston extended out. So, now the seal is holding the piston out and causing the brakes to drag. My buddy was telling me that he'd have to rock the car back and forth to get the brakes to free up. Weird. That's a new one to me. Interesting though. Quote Link to comment Share on other sites More sharing options...
Nigel Posted May 14, 2011 Share Posted May 14, 2011 Weird. That's a new one to me. Interesting though. Check out page 39 (second last page) of this Lexus Technical Training document: http://www.autoshop1...rms/brake04.pdf Nigel Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 14, 2011 Share Posted May 14, 2011 (edited) A friend of mine has Arizona Z car brakes on the front and rear of his 280ZX, with a line lock on the rear brakes. If he leaves the car overnight, or any extended length of time, with the lock on, the brakes wont release. I don't know if this is a common problem with using a line lock as a parking brake or not. Nigel '73 240ZT My original line lock, locked in the up position, or open position. I called Dave at AZC and he promptly sent a new one. I took the old one that was locked, and squeezed it in my vise. Fluid came squirting out of it, as the button freed up. I think fluid gets around the "seal" internally, over time. I don't think they were engineered for long term use. back to original topic. Edited May 14, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 15, 2011 Share Posted May 15, 2011 Check out page 39 (second last page) of this Lexus Technical Training document: http://www.autoshop1...rms/brake04.pdf Yeah, but that's talking about the pistons moving out as the pads wear. I always assumed that there was a limit to the elasticity of the piston seals, and after that was reached the piston then pushed through the seal and closer to the rotor. In this case the piston is sliding through the seal due to prolonged pressure on the pedal. I'm not taking issue with you or saying you're wrong, it's just different than what the Lexus manual shows, and not the usual scenario. For comparison, if you have 280ZX rear calipers and you pull the ebrake, the pistons still move in the seals to push on the pads, but they don't commonly slide past the seals and require retraction. Maybe there is a return spring in there and that's why they require the screw adjuster, I don't know. Quote Link to comment Share on other sites More sharing options...
Nigel Posted May 15, 2011 Share Posted May 15, 2011 Yeah, but that's talking about the pistons moving out as the pads wear. I always assumed that there was a limit to the elasticity of the piston seals, and after that was reached the piston then pushed through the seal and closer to the rotor. In this case the piston is sliding through the seal due to prolonged pressure on the pedal. I'm not taking issue with you or saying you're wrong, it's just different than what the Lexus manual shows, and not the usual scenario. For comparison, if you have 280ZX rear calipers and you pull the ebrake, the pistons still move in the seals to push on the pads, but they don't commonly slide past the seals and require retraction. Maybe there is a return spring in there and that's why they require the screw adjuster, I don't know. I don't want to side track this thread too much, but I wouldn't say that what I described is 'different' than what the Lexus manual shows. The Lexus manual doesn't talk about what happens if brake pressure is held for an extraordinary amount of time, and as you indicate, is not the usual scenario. So I was theorizing that if brake pressure were held for a long time with the piston extended, the seal could slide back to the position it would normally be in as if the brake pedal were released. Consequently, when the brake pressure is released, the seal would no longer act as a spring to pull the piston back in. Regardless, your comparison to a a caliper with an integrated parking brake is a good one, and after finding what information I could (not much) about the internal workings of one, it would appear that my theory probably doesn't hold up. I can't find anything that would indicate that the piston gets pulled back in mechanically when the parking brake is released. It looks like the piston floats at the end of the screw. It's probably a faulty linelock like cygnusx1indicated. Nigel Quote Link to comment Share on other sites More sharing options...
ZT-R Posted May 18, 2011 Share Posted May 18, 2011 i have a 72 240z and at the rear differential there are 2 "tees". i was thinking one was an actual tee and the other was a balance bar or something? Quote Link to comment Share on other sites More sharing options...
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