74.5 347Z Posted November 18, 2004 Share Posted November 18, 2004 I have pumped up my brakes and bled them several times without the engine running, but when the engine is on the brake pedal has no feel to it. At first, the pedal would go all the way to the floor, so I done some searching and found many post of people that had the same problem. I went thru the rod adjusting, bench bleeding, and even the mityvac routines that others had recommended. When I adjusted the rod, the only change is that the pedal doesn't go to the floor now, it seems to stop about halfway. I have the 4-runner kit in the front and the 240sx calipers/300zx rotor kit in the rear, both from Ross. A 280zx MC and Wilwood proportion valve. Every brake line, both hard and braided lines are new, so I gravity bled, bled and then used the mityvac to bleed atleast 10 resoviors of fluid. Still, I can pump the brakes up and bleed them with the engine off but no pedal with the engine on. It does have pressure on the rotors when the engine is on, but I have no way to tell how much. I hope that someone can point out something that I have missed because this is the last hurdle (HOPEFULLY) before I can take that long awaited trip around the block. Mark Quote Link to comment Share on other sites More sharing options...
DaleMX Posted November 18, 2004 Share Posted November 18, 2004 Sounds like what happened to mine. The reaction disk fell out of the power booster when someone changed the master cylinder. I bought a new booster and it solved the problem. By then I had replaced the entire braking system and still had the pedal to the floor problem. If the rod is pulled a bit from the power booster when the M/C is removed then the reaction disk will fall out and cause this problem. Quote Link to comment Share on other sites More sharing options...
74.5 347Z Posted November 18, 2004 Author Share Posted November 18, 2004 I know for sure that my rod has been pulled out several times by me, time to call NAPA. I did read some of the old post where that was mentioned but I don't remember if anyone said that that had caused their problem, unless I read over something. There is quite a few post where many others have the same complaint. Other than having no pedal pressure, do you know if the full pressure is being applied to the rotors? Thanks for your input. Mark Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 18, 2004 Share Posted November 18, 2004 Dale is right. It's the reaction disk. Quote Link to comment Share on other sites More sharing options...
74.5 347Z Posted November 19, 2004 Author Share Posted November 19, 2004 Great call. I replaced the booster today and everything works fine. Just got back from the first test drive. The brakes are not perfect, but I still have yet to adjust the proportion valve and bleed the entire system after reinstalling the MC. Thanks for the help. Mark Quote Link to comment Share on other sites More sharing options...
JoshB 240Z Posted November 19, 2004 Share Posted November 19, 2004 Mark, Which brake setup did you go with? Are you running stock or something aftermarket? Josh EDIT-Sorry. I missed your setup in the first post. Quote Link to comment Share on other sites More sharing options...
74.5 347Z Posted November 21, 2004 Author Share Posted November 21, 2004 I had the one that was in my car when I bought it. I replaced it with a remanfactured on. Quote Link to comment Share on other sites More sharing options...
mc Posted November 25, 2004 Share Posted November 25, 2004 ...what is a reaction disk?is it inside the booster or out???im having this same problem on the wifes 91 Nissan.....its driving me nuts and wasting alot of money. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.