240playtoy

Common problems include reaction disks. Replaced master cylinders can sometimes have different depths in the plunger, making your booster move before actuating the master cylinder. Here's some literature for you, I believe both problems are mentioned in it. http://forums.hybridz.org/showthread.php?t=113240&highlight=reaction+disk

Got most of my stuff from rockauto.com. Including my brake swap equipment....

I made the split gauges from 4 Norskog digital gauges. Removed the LED's, wired them up back on with wire extensions then put the whole setup back into the slightly modified gauge cluster.

My original parts are my sets of dual combo gauges. (Off and on) Now I've also installed Speedhut electroluminescent green tach and speedo covers and now I've got the dual gauges of volts and fuel level in place of amps and fuel.

As far as I can tell from what it does when it's gone, the reaction disk seems to allow your booster to modulate the force being applied to the MC. All the booster mechanisms still move when the reaction disk is missing, the only thing that's different is that when you press down on your pedal. You'll get essentially no braking power until a point, then nearly full braking power (locked up brakes). If all of your MC's (including your original) appear to "have the same problem" in that the pedal is soft, it's a very good chance it's your RD. Is your brake system stock? No swaps of different year MC's, boosters or anything like that? The one thing that's confusing me is that your brake light comes on, I don't remember that happening when I was having my myriad of brake problems. In my 240 only 2 things turn that light on, my parking brake and that "distribution" block the MC feeds into. I believe it shuts off front or back brakes if there's a loss of pressure on one side?

Gracias, Jon. I thought I'd seen something about that in a thread about how the cylinder works, but I figured I'd stay away from that as I didn't know much about it.

I don't know about pre-loading, if there needs to be some, then I need find a different adjusting screw as mine is out as far as it will go without falling out. I probably have less than a mm between my rod and piston, less than an inch of travel in my pedal before I get resistance.

I had to adjust mine due to using one of the ZX masters. But then, I think I also had an aluminum diamond spacer that went over all four of the bolts on the booster (~1/2" thick). In addition, your MC housing looks like it's got a deeper "shroud" on the back end of it than my original did. Does your MC fit flush against your booster without you having to tighten it down?

Just moving the plunger in and out doesn't mean your reaction disk is still in place. The reaction disk sits in a metal recess and the plunger moves into it as well. Check this for visual (my reaction disk is missing in the pictures). I do immediately notice a difference between your booster and mine (240z). Your adjusting nut in your picture appear to be between 1/4" and 1/2" longer than that on the 240. I now know why massive adjustment of mine was needed to remove my excessive pedal movement.

Here's the VATS bypass I used, a bit bigger. didn't see the other one from LT1350.com back then. Pretty sure it wires to a blue wire off the PCM, that and ground and power. I've got it hooked to a switch for a poor man's antitheft system.

The pedal is rock hard. (I've also got the stainless braided flex lines).

ich.... Which brakes lock up, front, rear or all? Then there's the common question I've seen asked "are you bleeders on the top of your calipers?". I have a feeling I'm not going to be of any further help. I'd recommend starting up a post about it with everything you've learned is not the problem.

If you "upgraded" to the ZX master cylinder, your rod may not actually be touching the back of the piston. I found mine hissed and wasn't firm until I was about 1" from bottoming the pedal on the floor. There was over 1/2" between the rod and the piston when I measured. Here's a quick little writeup that I posted a while back, but it seems you know about it (you were the only one who posted). So what issues are you trying to fix (description of sounds, pedal pressure and braking)?

I looked at my old booster, it seems that either I didn't have any retainer holding in the plunger or I lost it. the area surrounding the plunger was a piece of metal with a rubber gasket covering it. It pulled right out without issue.

after I got my booster off the car and the plunger out, I just shook it for about 10-15 seconds and magically, my reaction disk fell out. I think I was just lucky. Of course, this was after I purchased a rebuilt booster.