DAT240Z Posted May 25, 2005 Share Posted May 25, 2005 I replaced my whole break system (calipers, wheel cylinders booster and master cylinder) and now I have no breaks. When I apply the beaks the peddle goes all the way to the floor and barely function. I have bled the system more time than I care to remember. I have searched and read that sometimes the reaction disk in the booster falls out so today I took the old unit in and got another and still no beaks. When I replaced all the beaks components I up grade to the 280zx master, as someday I would like to do the Toyota four piston calipers swap. What I wonder is would the master cylinder be the problem because I’m still running the stock 240z calipers? Any idea would be greatly appreciated, as I would like to get my 240zt back on the road. P.S when the car is off I have a fairly good peddle but when the car is running it fades. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 25, 2005 Share Posted May 25, 2005 The reaction disk is one issue, adjusting the length of the rod going from the pedal into the booster is another. Most report needing to lengthen that thing by at least 3/4 of an inch. Were you getting fluid out as you pumped the brakes during bleeding. if the rod is too short, the MC won't pump until the pedal is almost on the floor. Quote Link to comment Share on other sites More sharing options...
Clifton Posted May 25, 2005 Share Posted May 25, 2005 If the rod is out to far it will not allow fluid in either. 71's usually need it lenghted but with out pulling you MC back off there isn't a way to know. You should be able to do it with out taking the brake lines off again. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted May 25, 2005 Share Posted May 25, 2005 Make sure the large reservoir ( for front disc) line is going to the right place. I remember that my 240 disc reservoir was reversed of the 280zx one. Quote Link to comment Share on other sites More sharing options...
DAT240Z Posted May 25, 2005 Author Share Posted May 25, 2005 Mike the reservoir's are the same size (79-280z) I have the reservoir in the back closest the the fire wall going to the front and the reservoir in front going to the back is this correct? One thing I have notice is that when The beark is appiled the car pulls VERY HARD to the right Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted May 26, 2005 Share Posted May 26, 2005 I have a 72 240 that I'm giving a 15/16 master; both the 72 and the later master have "F" and "R" markings, and they are in the same relative positions. Pulling hard to the right indicates two things to me- a) The master cylinder is moving at least some fluid, and You have a problem with the left front caliper/brake, as it is not applying (or at least not nearly as hard). Did you change the rubber flex lines? I've heard of a flex line failing in such a manner that the inner lining acts like a flapper valve, and blocks flow in one direction. (Not something I've personally experienced). Assuming that the bleeder is on the top of the caliper where it belongs, you may be able to get more air out of the left side... odd that the pressure doesn't equalize. Piston(s) stuck?? Quote Link to comment Share on other sites More sharing options...
orklc Posted May 26, 2005 Share Posted May 26, 2005 You said you changed the calipers. The left and right caliper are not interchangeable as far as I know. Are you sure they are in the correct side? We made that mistake in our rebuild and it was a pain to diagnose. Once we flip flop them, all bleeding went fine and pedal pressure was normal. My .02 cents. I am sure not everyone makes a mistake like we did. Quote Link to comment Share on other sites More sharing options...
DAT240Z Posted May 26, 2005 Author Share Posted May 26, 2005 I went out and check and the bleeder is on the top and the hose was changed two years ago when I relpaced the entire breaking system. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted May 26, 2005 Share Posted May 26, 2005 Mike the reservoir's are the same size (79-280z) I have the reservoir in the back closest the the fire wall going to the front and the reservoir in front going to the back is this correct? One thing I have notice is that when The beark is appiled the car pulls VERY HARD to the right You got it right. Some early Zs 70-71 and some early 72s have the large reservoir at the front like mine did. Those you have to reverse the lines, all other Zs have the large reservoir towards the back. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted May 26, 2005 Share Posted May 26, 2005 Any updates??? Quote Link to comment Share on other sites More sharing options...
DAT240Z Posted May 26, 2005 Author Share Posted May 26, 2005 no updates as of yet Bill I 'm flying to Ney York for the weekend I will be back Tue. I took tue. off work to work on it hope to have some info than. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted May 27, 2005 Share Posted May 27, 2005 Thanks, I've got to put a new Master Cyl in and when I do, I want to make sure that I do everything I need the first time. I am putting in a 15/16 ZX replacment, and my booster is new but it was shipped and I don't know if that disk fell out or what. Of course, I can't do much testing as my car has no engine... Quote Link to comment Share on other sites More sharing options...
DAT240Z Posted June 10, 2005 Author Share Posted June 10, 2005 I would like to thank everyone that responded to my post. I got my brakes fix and all due to this site and classiczcars.com. It turns out my reaction disk fell when I was adjusting the rod length. I search this site for brake problems and found a post about the reactions disk. So this morning I pull the booster out and took out the push to find the disk had fallen in the booster, I got it out clean off all the grease and super glued it the push rod, adjusted the length of the rod and my brakes are working perfectly Quote Link to comment Share on other sites More sharing options...
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