Cody 82 ZXT Posted May 9, 2005 Share Posted May 9, 2005 I've finally gotten the time to install the JSK Wilwood brake kit on my ZX. Everything has gone the normal route as far as installation is concerned but, I have what seems to me to be a defective caliper. Here are the details. The passenger side inboard set of pistons are not moving near as much as the outboard side. Meaning almost not at all. On the driver side of the car both sets of pistons move an equal amount. I have bled both sets of piston on the passenger side several times. I don't feel like that is the proublem. I will try to dismount the caliper and put something in between the pads and try to bleed the caliper with the bleed screws pointing perfectly up so I can elimnate this as a possiblity. Any suggestions? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 9, 2005 Share Posted May 9, 2005 Sounds like it just needs to be bled to me. There shouldn't be anything holding the piston in other than friction between the O ring and the piston itself. Have you tried jamming on the pedal really hard? I'd be really surprised if you had it properly bled and you slammed on the pedal if it wouldn't move. Maybe you just have a little stiction on that one piston and it will free up once it starts moving. Worse comes to worse a rebuild kit is like $10. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted May 10, 2005 Author Share Posted May 10, 2005 Sounds like it just needs to be bled to me. There shouldn't be anything holding the piston in other than friction between the O ring and the piston itself. Have you tried jamming on the pedal really hard? I'd be really surprised if you had it properly bled and you slammed on the pedal if it wouldn't move. Maybe you just have a little stiction on that one piston and it will free up once it starts moving. Worse comes to worse a rebuild kit is like $10. Well, I bled both calipers again with the bleeders pointing straight up and that seemed to help it out. I also removed the pad from the offending piston and put another pad in from my factory caliper. Just so happens that it fits and holds in place similar to the superlite pad. Anyway I stepped on the brakes and the pistons came out more than they had before proving that they were not defective. So now I decieded to just take it out for a drive with a pedal that was not as firm as I would like. As it turned out the more I drove and used the pads the better they felt. And let me just say that they are AWESOME. Wow they are so much better than the factory setup. The pads I have were used and I don't remember excatly what part # they are "Polymatrix" but, they are to agressive (lots of dust) so I will still need to find a better street pad. Before when you hit the brakes hard the back would always lock up first. Now the front are way more powerful. I'm now going to try some different pads and see how that goes after that I'll install a popertioning valve and adjust the bias for a better overall setup. Thanks for your help as always. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 10, 2005 Share Posted May 10, 2005 BTW did you turn your rotors before you put them on? Looks like more and more people are saying they had to, just wanted to hear your experience. Quote Link to comment Share on other sites More sharing options...
hat1324 Posted May 10, 2005 Share Posted May 10, 2005 how much was the superlite kit? I got quoted from percision brake company and am wondering what the difference is. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted May 10, 2005 Author Share Posted May 10, 2005 BTW did you turn your rotors before you put them on? Looks like more and more people are saying they had to' date=' just wanted to hear your experience.[/quote'] No, I thought I would have to but, as it turns out it seems to be running true. We'll see what happens after a few more real miles of driving the car. Another factor is that my old rotors both front and rear needed to be turned or replaced and now both ends are new so there has been a huge reduction in pedal pulsation. After a few days I'll have to pay more attention to it again to see if I think it can be reduced further. I also have a very worn out rack and pinion.New one is sitting in the garage waiting to go in the car. I think this worn out rack may be the cause of some of the front end movment as well as anything else. Looking forward to getting the rack in so that I can get the front and rear ends aligned after this last round of mods. The rear is already more solid since I replaced bushings and added the adjusting dodads. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted May 10, 2005 Author Share Posted May 10, 2005 how much was the superlite kit?I got quoted from percision brake company and am wondering what the difference is. The "kit" that I have and seveal others in the Z community is from JSK (link I have is broken) Basically it was rotor hat, cailper braket, and lots of bolts. You supplied the calipers, pads, rotor, brake line adators, and anything else that came up. I have about 700.00 or so into the kit. At the time I bought the JSK stuff there was not a Wilwood kit in the market now Dave at Arizona Z has two kits for the ZX. I would have bought one from him. It's been kinda a pain getting all the right stuff together. Here is the link http://www.arizonazcar.com/510brakes.html. I would have gotten the 13" kit if it was out when I got started. Quote Link to comment Share on other sites More sharing options...
EZ-E Posted May 10, 2005 Share Posted May 10, 2005 Those kits from Arizona Z look really nice and for the price I cant see it being beat, another great product from the guys at Arizona Z! Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 10, 2005 Share Posted May 10, 2005 I am glad you didn't get a defective caliper. It was probably just a tighter o-ring on one side due to tolerance issues. That won't be an issue because the drag from the oring/seal is negligable compared to the 1200psi of pressure from the fluids during braking. Just make sure that the pads don't hang tight against the rotor when you lift off the brake. I bought the 12.2" kit from AZ. I love it. I have been hammering on it for about a month now and it is phenominal. Cold, it exhibits a slightly high pedal pressure but once it is warmed up just a little, it is amazing. I have "street" pads. The pedal remains firm and the modulation is great. The cockpit proportioning valve is nice too. I did have to turn the front rotors even though they were new. Dave explained that the warp comes from tolerance stack-up during assembly. I have not had it out on the track yet but I can't imagine needing more...at least with my current engine setup. Nothing builds confidence like GOOD brakes. Quote Link to comment Share on other sites More sharing options...
Afshin Posted May 10, 2005 Share Posted May 10, 2005 Hi Cody, glad you got the car back on the road. I absolutely love the big brake set up. Feels good every time. BTW one of my two rotors needed extensive turning when new. Also, I have noticed that the wWilwood calipers are pretty good at trapping air, specially as the pads thin out and the pistons are extended out. Make sure you tap on the calipers when bleeding them, it often can help dislodge some trapped air. Also don't forget to set some toe in on the rear suspension, it really cures the tendency for excessive throttle oversteer and stabilizes the back when pushed. Regarding pads I had a set of Portefield R4-S (aggressive street pad with reasonable track ability in a light car with big brakes that run relatively cool) which where pretty good. I recently replaced them with Hawk HP plus (real track pads, but not serious race pad and safe for street/cold use....) I was told that they work great but generate more dust and noise. I figured I would give it a try and if too much (I hate noisy pads on the street) I would use them on track days only. However, much to my surprise, not only did they work better than the milder portefields R4-S pads, as expected, both hot and cold, but they generate no noise whatsoever with my Wilwood set up (lots of grease on the back) and I can't notice any significant increase in dust. I have not had them long enough to comment about rotor wear, however with the big brake set up on a light car (that is compare to modern day cars, not a 240), I would not expect too much wear. Jon, if you don't mind what has your experience been with the pads? Lastly Cody, what happened with the rear brake set up? Quote Link to comment Share on other sites More sharing options...
johnc Posted May 10, 2005 Share Posted May 10, 2005 Warp: http://www.stoptech.com/whitepapers/warped_rotors_myth.htm Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 10, 2005 Share Posted May 10, 2005 My experience has been limited to some conjecture as to which ones I'm going to buy. I think I'm going with the Hawk Black pads based on John Coffey's experience. My car has been in limbo for a while. I took on WAAAAAAY too many projects at the same time. Thinking that I might have to not get some of them done and just slap it together again. It's been apart for a year and a half and if I can actually get the weather to cooperate and work on it every day I might have it back together by the end of summer. Just for reference I was saying end of summer in Jan 2004 too. It's all about having time/money/parts at the same time. Seems like I always have 2 out of 3... Quote Link to comment Share on other sites More sharing options...
Afshin Posted May 10, 2005 Share Posted May 10, 2005 Hi John, the stoptech article is a nice one, I have a print out and had posted the link for it here on HybridZ a while back. The interesting thin when I got the wilwood rotors, is that they were warped brand new, before braking in the pads (so I could not have screwed that up). WHen turning the wheel after the install the rotor would touch the pads at the same point (like a warped bicycle wheel), I thought it was related to the pistons not being set in since I had not driven it yet. Then on the first drive around the block it knocked so hard I thought something was broken or that I forgot to tighten a caliper bolt..Made sure the hat/rotor bolts were properly torqued (they were done in proper sequence) and all was seating properly....Took it to the shop and indeed the rotor was warped, we turned it and it fixed the problem. I was quite surprised. Quote Link to comment Share on other sites More sharing options...
Bluto Posted May 10, 2005 Share Posted May 10, 2005 Talking to prieth (who has the azc big brake set up) and he told me that dave told him he would "need" to turn his rotors after they were mounted to his hats. I'm not sure if this was because of his hats or because of rotors that arent square and true. I have the jsk hats myself but have not had a chance to put them on a lathe to check'em. If these hats atrent true I will not be a happy kiddie. I'm not sure if you would even be able to have a spare set of just rotors that could be turned befor hand and remounted on the same rotors and the same orientation. May need a spare set of hats also.. very annoy9ing if this turns out to be the case. Preith ran into this out the hard way at his school/race event. Sam Quote Link to comment Share on other sites More sharing options...
Mike Mileski Posted May 10, 2005 Share Posted May 10, 2005 Good luck on getting any spare JSK hats. I think JSK Innovations is now a thing of the past. That's based on 10 months of unanswered emails and phone messages and now a defunct website. Mike Mileski Tucson, AZ Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 10, 2005 Share Posted May 10, 2005 I know Stoptech makes some really good stuff, but: I disagree with their theory that rotors don't warp. Now, there is absolutely no doubt that pad buildup on the rotors cause all the same symptoms as a warped rotor. One of my good friends has a brake lathe and does all my rotor work, and I've seen rotors that from the point the cutter first touches the rotor it takes 15 thou more cut to get the cutter cutting all the way around the rotor. There is no doubt that the rotor itself is warped, not just a matter of pad buildup. I've never had to turn a Wilwood rotor, I'm speaking of stock vehicle rotors, mostly Dodge pickup stuff since that's what we use in my business. Regarding the Wilwood rotors, I've been thru six sets since I put the DPR kit on my car, Superlites and 12.2 x 1.25 rotors, and I haven't had a new one have any shake to it yet. The DPR kit uses the GT48 series rotor and they've all been straight as a gun barrel. John Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted May 11, 2005 Author Share Posted May 11, 2005 Lastly Cody, what happened with the rear brake set up? Heres sneek peek http://album.hybridz.org/showphoto.php?photo=2532&cat=500 http://album.hybridz.org/showphoto.php?photo=2533&cat=500&page=1 84 300ZX non-turbo rotors 11.5" I think Caliper bracket is made out of 1/2" steel I think you can see how it was made from the pics. Let me know if more pics would be helpful. So far it seems to work well. Before I installed the front kit the rears were over powering. It was also like this before the larger rotors and all. Basically it seems as thou the stock caliper with the larger rotor made a small differnce in braking power over the stock rotor. It also looks alot better then the 10" rotor with the 17" rims. I ordered some of the Poterfield R4S pads for the front today and I'll have to see how everything works out after I get them in and broken in some. I think I may need 1 or 2 things or maybe even both beofore I get finished with the brakes. 1. New pads for the rear. I think I'll try the Potorfields for the back also if I like the fronts. 2. Proportioning valve to help balance out the system. It may take both items to get a good balance. I'll report back on the rear setup as soon as I can get some real miles on it. Quote Link to comment Share on other sites More sharing options...
johnc Posted May 11, 2005 Share Posted May 11, 2005 Carroll Smith wrote that article on the StopTech web site and he is talking about racing pads and rotors. Also, part of the article mentions rotors changing shape as a result of being firmly fastened to the hats. I think that can be carried forward to street rotor installations and can be a reason rotors change shape. Quote Link to comment Share on other sites More sharing options...
Afshin Posted May 11, 2005 Share Posted May 11, 2005 Thanks for the pictures Cody, looks good The rotor appears significantly larger than the 280zx, it should improve the rear braking torque nicely and help it better match the new large front rotors. Would you have a photo of the caliper mounted to the bracket (from behind the rotor) ? Keep us updated. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted May 11, 2005 Author Share Posted May 11, 2005 Thanks for the pictures Cody' date=' looks good The rotor appears significantly larger than the 280zx, it should improve the rear braking torque nicely and help it better match the new large front rotors. Would you have a photo of the caliper mounted to the bracket (from behind the rotor) ? Keep us updated.[/quote'] Take a look http://forums.hybridz.org/showthread.php?t=101230 Quote Link to comment Share on other sites More sharing options...
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