KDMatt

Ok, it's out and I cleaned it up. My trans looks a little different than "normal" 280z 5-speeds I'm seeing on ebay. I've got a second switch where the fill plug seems to be on other cars -- my fill plug is on the driver's side. Thoughts? Also, what comes next? FSM isn't too clear on removing the spring and the bearing up front. I want to pull the gearbox away from the bell-housing to see which one of these bearing cages got chewed up.

Got it! Thanks Zed Head. There was so much crud on the thing I missed the two 12mm nuts/bolts at the bottom. Now my only problem is that my ramps aren't high enough to let the bell housing slide out, so I need to jack it up a few more inches, d'oh!

Hey guys, quick question -- is there a trick to getting the tranny to come out? I've been at it for a couple of hours now and I can't get it to separate from the engine more than about half an inch. I removed the crossmember that holds it up, and 4 bolts that hold it to the engine, along with the switch wires, speedo cable, and clutch slave ... What am I missing?? I'm supporting the engine with a jackstand just in case, and the trans with two jacks... I've tried raising it up, lowering it down, trying to put it about even with where it was mounted up... whacking on it with a mallet, using a pry-bar... I'm pulling on it as hard as I can (on the ground nonetheless) and it just won't let go. What gives???

Confusion is A-ok at this stage in the game my friend. Just gotta take it slow and go one step at a time. Still sounds to me like you might be having some issues with your booster... but we'll cross that bridge later. Get those new brakelines on there and we'll go from there. If you try to troubleshoot everything at once you're going to go a bit nutty. Trust me, I've been there. Please take lots of pictures as you go forward too -- that really helps us on these forums. I mean, you're in Florida and I'm in Minnesota. My imagination has its limits. To illustrate the reaction disc I did some googling and pilfered these images from another forum. I hope this explains it a bit better.

Hey there VB! I hope I'm not overloading you with info. Ahh yes, if your lines are cracked then yes there's no time like the present to replace them. Once you get that done, bleed the system again and see where you're at. I too had issues with rounded off nonsense, and I think ultimately mine were so corroded into place, I just left them there, and zip-tied the new lines into place alongside. As others have suggested, a vice-grip is kind of your best go-to for cracking those suckers loose, otherwise, worst case scenario, you might just end up replacing sections of your line (like I did -- I think about half of the brakelines at the front of the car have been replaced since the fittings on the old ones were so bad) -- Oh, also, if you feel so inclined, you might want to have a cheap flaring tool on hand, just in case you need to cut/gut bits of hardline on your car. Being able to make a new fitting will make you feel a lot more confident when you're ripping things apart ... but first things first, just try to use a vice-grip to clamp down on that sucker and use a good mallet to whack it loose. Remember, lefty-loosey! As for the reaction-disc, it's a little rubber disc about the size of a quarter that sits on a metal plunger in between your master cylinder and the actuator in the booster (see attachment.) Most people who've had this thing come loose will just clean off the surfaces and just epoxy the silly thing into place so it never moves again. Why, after all of these years, nobody has thought to glue these things down from the factory is beyond me. The tell tale sign of a fallen/slipped reaction disc is in the brake-feel. Your pedal will travel quickly and easily down, and you'll get no braking throughout that movement until you suddenly hit a point where it feels like your brakes are hard on. It's really hard to describe. As for paint, the booster doesn't really get hot, so you can pretty much use anything you want. I had some left-over satin black laying around and hit mine with a few coats of that, and it's worked out fine. Let us know how your troubleshooting progresses!

Just so I understand what's going on: You're replacing your brake lines with SS ones because you've got sloppy/spongey feel in the pedal? Is that where we're at so far? Your original problem (going back in the thread) sounds to me like you had a bad brake booster. If you've bled at the master, and bled at the corners and everything seems good, I'm not convinced that SS lines are going to help you too much. Did anybody warn you about the reaction disc when you put in your new booster? It's a little rubber disc that slips between your master cylinder and your booster that's held in with a bit of grease from the factory. Mine slipped out when I changed my booster and the brake feel I got was very... uninspiring. I'd get all kinds of pedal movement but not a lot of braking until I reached the bottom of the pedal's travel, which translated to me as "sponginess." On your image on the previous page, my booster looked like the one on the right ... I'm guessing maybe you ended up with one for a 2+2, which isn't inherently bad in any way, but it would probably change the behavior of your brakes a bit. No idea if the 2+2 boosters are as notorious for dropping discs either, but I thought I'd mention it in this thread since nobody else had. Just a bit of food for thought. I chased brake gremlins for about 2 years before figuring out I had both poorly adjusted shoes in the back, and a slipped reaction disk in my booster. Fixed those things after I figured out what was wrong, and my stock brakes are tight and firm. The stock brakes on a Z can launch stuff from your rear compartment up front with you if you really slam on them - no SS lines or upgrades required. Oh, and if you pull your booster out again, now is the time to hit it with some paint. That gray "finish" is really just unfinished metal, and it's going to turn into a rust finish in a few years.

I keep hoping I'll stumble across a really great, annotated writeup with tons of pictures to help me feel more confident about this... but it's not happening, lol. I guess you're right though, in that there's no harm in cracking it open just to see how bad it is.

I got a quote for about $700ish to pull it apart and replace the seals and bearings. Price doesn't include doing the synchros. I dunno, I've paged through the FSM and this looks like a pretty complex ordeal. At this point, I'm almost tempted to try to snag another transmission ebay for a couple hundred bucks, and just keep this one shelved until I've got the courage or (savings?) to rebuild it. My Z is, by no means, a looker right now. I'm really torn though -- I can justify both decisions pretty easily. Here's a random question though ... My transmission has two sensors on it (one for reverse light -- the other for...??) -- most of the replacement transmissions I'm seeing on ebay (allegedly out of 77/78 Z's) only have a provision for one.... am I just being dumb and not seeing it or what's the deal? I'll take a pic when I'm home.

I guess I'm going to need to see some pictures to see if this is something I want to do or not. I found this thread, but alas no pics: Generally speaking though, yeah -- that's been my approach to this car over my time with it -- just replace what's broken, and leave things alone that aren't broken and just go from there. Dropping the transmission is a bit labor intensive though, so I don't want to go through all of this trouble only to have to do it again in a year or six month's time. I dunno. Granted, it's probably been "busted" like this for several years/thousand-miles, so who's to say. Is it less labor-intensive to crack it open -- just replace the broken bearings/cages and call it good? Also, I don't have a definitive clue what 5-speed I've got, so there's that. Waiting on estimates from a couple of places in town for a rebuild, and we'll go from there.

Already done. The transmission is ready to come out. I spent all day yesterday getting everything everything out of the way and disconnecting all the monkey-business stuff, like speedo cable, reverse switch, neutral switch, etc. etc. Exhaust is on the floor. Shifter is out. Console is out. Starter is out. Slave cylinder disconnected. I think at this point I just need to put a couple of jacks under the thing and unbolt it. Also, Mark, I did see that thread ... I perused far enough to see the pictures of the bits he removed looked like mine, and that's about where I stopped. If he documented a full tear down, I didn't get that far. Good to know that it's there though -- I'll look closer. $100 seems pretty optimistic, but I suppose there's no harm in calling around. Here's the other rub -- this is a swapped 5-speed that was neither done by me nor the P.O. -- which means it was swapped at some point in the late 80's or early 90's ... and I'm not super sure if it's the ZX tranny or the 77/78 ... which I'm sure will complicate my quest for rebuild kits/components. Sorry for addressing out of order. Yes, that's what I was trying to get at -- bearing cage. Thank you. The transmission never whined or gave any otherwise indications that a component inside had failed or fried, which is why I was astonished to discover such critically important parts just sitting at the bottom. :/

I'm tackling a clutch job for the first time in my history with this car (11 years/35k miles), and as such, I cracked the drain plug for the first time in at least that long. I have no idea when it was last done -- somewhere I've got a stack of records that would probably tell me if it's been done anytime "recently" in the car's history... but for now it's an unknown. The fluid that came out was pretty sludgy and gray, and as expected there was a pretty thick layer of metal crud on the magnet plug, but, on top of that, I found a couple of bits/chunks of metal. I searched some previous threads and saw someone else with something similar -- it looks like some bits from one of the gear bearings? I have no idea how long these parts have been down there. For all I know these things could have been down there for decades. I'm assuming the worst-case scenario is that I need to crack open the transmission and rebuild/replace these assemblies. That being the case, is there a section in the FSM that covers how to do this? I've never cracked open a transmission before (hell I've never even done a clutch before - so I'm already in unfamiliar territory), but there's no time like the present, I guess? How big of a job are we talking about here? Could it be done in a weekend? An afternoon? If you were me, what would you do?

Tremendous! Thank you!!

Hey everyone! it's been several years since I was last an active participant of this community, so forgive me if things have changed! I've had my Z for almost 11 years, and once upon a time there was a great, definitive procedure for changing the valve-stem seals. I'm wondering, first, if that's archived anywhere (since the original was on Geocities and I can't really find it anywhere now.) Second, what is the tool people are using for this job these days? Back in the day, the tool folks swore by was KD Tools #3087, which was supplanted by a Jet tool #H3349. I can't find either of these anymore, and I'm wondering if anyone has any experience with this one: http://www.amazon.com/Neiko-Spring-Compressor-Universal-Overhead/dp/B009GLIOSE/ref=sr_1_20?s=automotive&ie=UTF8&qid=1461721775&sr=1-20&keywords=valve+spring+compressor It looks to share a lot of the same design qualities as the KD Tools one, but uses its own bar instead of hooking around the cam. Has anyone ever used one of these on a Z, or would I need to be a guinea pig? Thanks in advance! It's good to be back!

Final Update: I think I've got her fixed! I took a break from the car for a while, went out of town, came back to it, tackled the issues one more time, going slowly and methodically, and I have finally achieved the results I was looking for. As it turns out, I had not just one failure/error, but two, if not three, all of them cascading on one another to make my life a living hell for the better part of a year. So as to, in a way, "conclude" this thread, I will go through everything that went wrong. The first ingredient was the rear brake cylinder that popped its seal. The rubber tore and leaked out all of the brake fluid, which in turn prompted me to replace both rear cylinders, and brake shoes. Error 1: It was only recently that I realized I did not have the new shoes adjusted properly, even though I honestly, truly, thought I did. In bleeding the new cylinders I came to the conclusion that my old master cylinder wasn't moving enough fluid, so I replaced it. Error 2: Pulling the pushrod out during the replacement of the master cylinder, which I did twice! ... because... I finally crawled underneath the dashboard and did the contortionist thing to pull the brake booster out of the car.... and sure enough... Error 3: The reaction disc had fallen out. So, in conclusion, it was ultimately a combination of mechanical failures combined with a healthy dosage of inexperience on my part that led to creation of, and prevented my recovery from a seriously bizarre concoction of symptoms, caused by a combination of problems and oversights. I am very confident now that I have rectified the problem. Even though this thread has been a couple of months in the making, I just want to thank everyone that contributed and kept me encouraged. I kind of have my foot in my mouth a little bit on this one too, but those of you shaking your head at me can at least take some solace in knowing that I probably spent a lot of money on this project I didn't really need to! :stupid: Live and learn I suppose! Cheers, everyone!

Update: @madkaw: I pushed the fluid through the system backwards and got clean results at the master. So as far as I can tell, the lines are bled and A-OK. Here's an interesting development however, and see if you guys can follow me on this one. I remember reading a while back about the adjustment of the pushrod from the booster to the master, and that one of the symptoms of having one adjusted out too far was premature brake locking (i.e. while driving), and that the only way to fix the system was by relieving pressure in the master. Seeing as my symptoms are essentially the opposite of this problem (i.e. won't lock at all, and seeming lack of pressure in the system) I figured there was no harm in fiddling with the pushrod. I adjusted it out a pretty significant amount (don't worry, it's marked so I can put it back the way it was originally if need be), and to my surprise (if not amazement?) the pedal began to feel much more like I remembered it feeling long ago. What's more, when I took the car for a quick spin I was able to get the brakes to lock when I slammed on them, which was something I was completely unable to do before. I'm starting to think perhaps I did lose my reaction disc after all, and the adjustment of the pushrod outward is just compensating for the distance lost. I'll fiddle with it a bit more (certainly as my adjustable proportioning valve seems to need, well... adjusting), but I'm curious to hear your guys' thoughts? Does this seem like a plausible explanation? I still find it odd that my pedal travel was met with some resistance all the way through its travel before, but then again this is all pretty new territory for me. I just want to make sure that if this does indeed rectify my issue, that it isn't only masking what might be a more serious, latent problem. Thanks for sticking with me, guys!

@madkaw: Should I try to force it back up to the master, or should I be cracking open the bleed screw to do it?

Oh goodness, I didn't see that this thread had still more replies after my last one. ... and no, this isn't a "Zombie Thread" as I am still very much in the throws of frustration! I apologize that I haven't been keeping everyone up to date here, but I've been swapping ideas with some of my local Z guys to get their two cents on this. The general consensus was that we shouldn't completely rely on the Autozone MC, so I ordered the $160 one from MSA. I also decided that I didn't want to risk the possibility of air leaking in through either the proportioning valve nor the check valve, so I ditched those as well. I now have the front brake circuit running off of a T-fitting, split directly from the master cylinder, with a 10mm union uniting a couple of the pieces of line. For the rears I got an adjustable, inline proportioning valve. Also, T-Man, to avoid using the cheapie flaring tool I have, I ended up just buying a lot of pre-made brake lines of differing sizes to do this work, just to make sure the flares were solid. So, now, I've got all of this new stuff on there... bled the crap out of everything. I even bought a special tool for bench bleeding the master. Everything is coming out totally clean, bubble-free, and fresh looking. I can hear and see the brakes engaging, and yet the pedal still feels super soft. I'm still picking the brains of my local chapter of guys, but at this point I'm really starting to lose faith in this car. I know I said I'd take off the brake booster, but I never did get around to doing that. I removed the air hose going to it because the reversed air coming out with each pedal push was making this horrible groaning noise in the check valve. I'm guessing it's normal for air to flow out of it when the pedal is being pushed down? Should I try pulling off the calipers and letting the "pucks" (as one previous poster referred to them as) run out, and then squeeze them? I'm getting close to that point where I either need to get it towed to a qualified brake shop and let them deal with it, or I'm just going to part it out, sell it, and just be done with my 8-year Datsun love affair. The brakes on this thing haven't been "right" since Fall 2011.

@Blue: Alright, I'll do the gymnast thing again and get my head under the dash to adjust the pedal a bit better. Question though: How do I check the rod going into the master? Would that really cause the pedal to feel THAT funny?? The note that I forgot to make in the video is that as I go down the line of brake fittings, the squishiness/sponginess gets progressively worse as I connect more and more things. @ Pete: Alrighty! I've read up on the reaction disk, and while my symptoms are quite different from what most people experience, I'm really not above ruling that out either. Is there a way to make sure it hasn't slipped out with the booster still on the car?? I could yank the thing out I guess, but I really don't want to! Taking it apart looks like a nightmare! @ Travel'n Man: Yep! It's a Fenco rebuild from Autozone: Fenco Reman/Master Cylinder (Brake System) (M51658) | 1976 Nissan/Datsun 280Z 6 Cylinders H 2.8L FI | AutoZone.com If I could find the paperwork on it, it does have a lifetime warranty, and I could always make them deal with this instead of me! I'm curious about the 15/16" and 1" master. Do you have any links I could read up about that on? I've toyed with the idea of going with discs in the back at some point in the future, but never took steps to actualize that. It would certainly fit within the Z -mantra of "Well since I'm replacing <x thing> anyway I might as well do..." I'm already going to lose the check valve, and probably go with an aftermarket/universal proportioning valve, just to keep both circuits truly isolated from each other and keep things nice and simple. @ LeonV: That's what I thought too... I guess now I'm not so sure? I don't think it's totally "dead" as it does at least move fluid, but it certainly doesn't feel rock solid. At this point I'm just guessing! ... also, have I mentioned lately how much I hate flare fittings? haha

Hey guys, sorry it's been a while since I posted. I decided to shoot a video to better illustrate what's going on. Hopefully the running commentary along with the visuals will help inform the issue here. I'm thinking master now? Let me know what you folks think. Thanks again for the help.

I'm going to bleed the master one more time before I say for certain one way or the other, but yeah, I'm kind of feeling this. I might shoot a quick video to go along with this too, just so people can really get a sense of how much play I'm getting in the pedal. I really want to be 100% sure that the master isn't functioning properly before I order ANOTHER one. Also, I'd be tempted to go with another provider if I do indeed need to replace the master cylinder again. MSA is almost prohibitively expensive, but I'm curious to hear thoughts on Black Dragon? $100 is steeper than the $40 I paid at Autozone, but a definite improvement over the $270ish at MSA. @ altnernativez: Thank you for the words of encouragement and Zen approach to bleeding! I concur with the note about "gravity bleeding," and I will definitely give this a shot. Thing is, at the moment, the master cylinder is isolated and plugged off, so there's nothing to bleed again just yet! Also, I'm thinking of using some couplings and a T-fitting to bypass/remove the check valve -- I get the sense that most of us car savvy drivers don't really need it anyway, and it's just one more thing that complicates stuff. Hell, I might even get rid of the stock proportioning valve and get an inline one for the rears -- it should certainly make things a lot simpler if I decide to do a rear disc conversion ... assuming I can get all of this working again... :x Also thinking, at this point, Speed Bleeders might be a worthwhile investment. Yes? Thoughts and opinions, as always, are appreciated.

Quick Update: I'm not sure, but I might be on to something now. I plugged off the outlets on the master again, and started to give it another round of bleeding, and I'm noticing that when it's sealed off, closed up, and plugged off, the pedal still has a bit of squishy give to it. It's been so long since I've had 'normal' brakes, I can't remember how much give is normal in the pedal, but I feel like with the master cylinder isolated and blocked off (and properly bled, well theoretically) there shouldn't be any movement in the pedal, or at least very, very little, yet I still get some. I was having these symptoms with the original master that was in the car, and while it does seem a bit unlikely that the rebuilt unit I have in there now would also be bad, I'm having trouble ruling it out entirely. It was a relatively inexpensive rebuilt unit from Autozone, and at this point I'm not above casting some doubt on it. What are you guys' thoughts? How much 'give' should my brake pedal have with nothing attached to the master cylinder?

The Flex lines have all been replaced. The rears were done last year, and the fronts were done two years ago. Thanks for the suggestion though.

Hmm... the last time I tried, I couldn't get my wheels to lock at all... It seems like the further down the line I go (in terms of plugging fittings and testing for pressure), the less power I have. Could I have had two bad master cylinders in a row? I'm still very puzzled about the behavior of these brakes.

Yes, the check valve for the booster should be correct, as I replaced the booster several years ago and have had no issues with with anything brake related up until now. In fact, even now, the booster is still giving me more braking power when the engine is running as it's supposed to. I'm having a different problem than user "djwarner" as my pedal is not stiff, but spongey. I'll double check the rod for the master, but as I mentioned before, I was having issues before I even touched the master cylinder, so I don't think this is my problem either. Still curious to hear what people think about the proportioning valve.

Hmm... I suppose that's possible? Thing is, I had this problem with both my old master, and now with my new replacement one. When I plug off the outlets from the master, the squishiness goes away, to the extent that the pedal will barely move (as you might imagine it would) which leads me to believe that the master is in pretty good working order. I don't notice any pedal sponginess returning until I get the proportioning valve hooked back up, so I'm really not sure what that's all about.