This is going to come off as a huge rant and maybe it is but here goes. Previous owner of this car, a friend of mine purchased it with no brakes. He had to replace the master cylinder as far as I know. Ever since I've owned the car it has had really spongy brakes but they worked okay but, I still wanted it fixed. I take it to my friends dealership and we put it on the lift, change the rotors, pads, then bleed the whole system.

Still the brakes are way too soft, I mean marshmallow soft. I've been putting off bench bleeding the master cylinder but, today I finally decided to go on with it because my mom is flying in from new jersey and I wanted my car driving nice, I dunno some paranoid thing, I haven't seen her in over a year.

I start out missing some vital things but, oh well I'll manage. I get the master cylinder off and quickly realize that I have nothing to plug the line holes with. So off my brother and I go driving to multiple stores looking for something that will work. Finally hours later and well into darkness we get some plumbing block off plugs that fit perfectly.

We get back and plug up the holes, fill up the tanks and get my handy new pump out to start bleeding away, air lots and lots of air in the lines, in fact way too much. So we try fitting the hose better, we try tightening up the plugs some more, we try everything and still nothing but, air. We the pull off the bleeder screws and clean them up, they're rusty but in otherwise good shape. As Im putting them back on I realize the problem. Inside the MC there are essentially no threads for the bleeder screws to hold on to, stripped out completely. So everytime we loosened it to let air out, we were letting air in.

Extremely pissed we tighten up the bleeder screws, hook up the hose, and very slightly back off until just barely fluid can come out, hoping that this will do something. We finish up and my brother (as usual) insists on installing the MC himself since thinks he can do everything better than I obviously (younger brother on some power trip to prove himself) he barely even gets the first brake line on and moves onto the other all while letting fluid drip down all over the car and everything under it as well as letting even more air in.

Anyways, we get it back on and it's worse than before but, the car seems drivable. I really appreciate his help but, sometimes he makes things worse by being arrogant and not even listening to what I have to say. I guess now I have to buy a new MC among other things.

 

Damn!

Double Damn!


Rod.

 

Were you able to determine if air in it was indeed the problem or was something wrong with the MC before your bro got ahold of it?


You didn't mention if you changed the brake lines, and I don't know if Z cars have rubber brake lines, but I'd assume they do. I've found on other cars replacing old worn out brake lines (Even on something as new as a 95 model car) with stainless braid supported lines makes a substantial improvement to the pedal.

 

I think you didn't understand how to bench bleed. You dont have to open and close the bleeders like on a brake caliper. You just open up the bleeders a little untill they release just a small amount of fluid. Run a line (rubber or whatever) from the side up and back into the top of the resivours. Just push the master cylinder in with a rod or dowell. I don't know what you needed a 'pump' for. You keep flushing the fluid out and back into the top. The air will escape.

Any automotive store should have a little brake bleeder kit with some hose and plugs for the master cylinder. Should be right on the shelf. maybe $5 or so.

The process of bench bleeding is spelled out in the FSM and the Haynes manual with pictures. or just search online. I found this article with some decent pictures.

http://www.superchevy.com/technical/.../0509sc_bench/

 

My brother didn't really mess anything up he just kind of made things worse when putting it all back together, because of all the air going through the lines it was hard to tell whether or not is was the original problem. I can only assume that it was since I know the previous owner did not bench bleed this MC upon installation.

I bought the pump to make things easier for when I wanted to bleed the brakes but, while reading the book it also mentioned that it could be used for bench bleeding as well. I also bought the pump because it's not only good for brake bleeding but, also checking the entire vacuum system with a detailed description of what vacuum readings can tell you (ie sticky valve, worn piston rings, etc).

I also have the cheapo bleeder kit that I used before but the hose is too small to fit around the bleeder screw and the fittings it comes with are just pointed needle type things that fit inside the hole and easily come loose.

Before I even thought about bleeding the system I read up as much as I could and I guess I didn't find any decent sites or books because none of them mention reusing the fluid. Perfect though because we went through quite a bit of it last night.

Next time I try it with or without a new MC I'll be sure to go over my dad's house so that I can use his vise though, fo sho lol.

 

Oh and how bad is it to have rust in the MC where you have to use the rod to push it in? Because mine has quite a bit but, no visible trash showing in the fluid. This is supposed to be a new MC but it looks like it could be a junkyard piece.

 

Oh and I plan on getting SS lines for the front brakes and the SS line for the clutch line as soon as I get everything working the way it should but, for right now my money is tied up in moving and bills.

 

rust inside the cylinder is bad. That can allow fluid to leak past the seals on that main piston.

you can pull the piston out, replace the rubber seals, hone out the cylinder (if you can find a hone small enough) and then put it all back together. Don't hone a whole bunch. Its not like you're porting it out, just smoothing the surface a little.

now you have a better idea of what you're doing. You'll get it next time. Get the little clear tubes that fit over the end of the bleeders. run them up into the top of the resivours.

 

Okay so I just had the most stressful and upsetting night in my life. This car is seriously starting to **** me off, it's getting to the point where I just want this piece of **** out of my life for good. Most of the problems are thanks to the previous owner who is a complete mechanical retard. Let's start with what I did today.

I went to Oreilly Auto and found out that the store on Pace and Jackson had a reman MC in stock for $37 a new one would have to be ordered and would cost $133. I figured that since I already have rust in the cylinder and because I've had such bad luck with this one I'd go ahead and get the reman MC. Well the reman also came with plugs for the bottom that have holes in them to run line with, although the line was too short I found that aquarium airline tubing (about $1 for 8') works perfectly and it's clear instead of the supplied black tubing.

So far I was very happy because I thought this would solve all of my problems. I went to my dad's where he has a vise and my brother and I began to work. I pulled the old MC off in no time and had everything cleaned up and taken apart. I put the resivours from the old one onto the new one and I put the MC in the vise holding it in place by the mounting flange.

I put in the plugs and hooked up the tubing, filled up both resivours and I grabbed a phillips screw driver. I started pumping and clearly saw bubbles going through the lines, the more I pumped the fewer there were until I saw none, I let it rest and pumped a few more times just to make sure. Then I took the caps there were on the bottom and put those on since they would be easier to remove once we mounted the MC.

So, I loosely mount the MC and go to hook up the first line, fugging great, the damn nut on the brake line seems to be stripped. I mess with it for several mintues until my brother takes over, then he moves on to the rear brake resivour line and gets that on easily. I go back to trying at the front brake line nut and finally after about fifteen minutes finally get it to thread and it tights up perfectly, I just had to apply some pressure while threading it.

Ryan hopes in the car and starts it, pumps the brakes and keeps pumping, doesn't say **** which pisses me off and then says it feels the same as before even worse maybe. I get in the car and it is worse, super soft right to the floor. I slowly back up and I have no brakes, so I pull back up and use the E-brake. The resivour was just barely low, I mean only a little bit so I top it off and I don't know what happened but then the brakes worked. but there was still no pedal pressure.

I lift up the front end just to see if bleeding the front brakes will show any improvement (by now it's well past 10:00pm so I really don't feel like doing all of the brakes) I bleed them up front until I see no bubbles and we try it again. Still the same, no improvement. I say fugg it Im done for the night I love this car but I have all this bullshit I have to put up with.

Then I drain the radiator cleaner that's been in my car since wednesday and I flush it out with fresh water, then put in some new coolant and distilled water, Im sitting there for more than 30 minutes waiting for the thermostat to pop and it never does, so either it was still open from when it popped during the "just water" flush or it froze up, because I can't see any water moving from the top hose. Great something else to fix.

Only to make things worse, brake fluid is leaking from somewhere, it's all over the paint on my car and my brakes are even worse than before and Im scared to drive but I have to have a car by monday for work. I tried to be as detailed as possible incase I overlooked something, I can try and bleed the rear brakes but, I highly doubt there is so much air in the lines that my pedal will go all the way to the floor and the brakes will hardly work.

 

If you're not getting any pedal pressure and you've got fluid leaking then its possible your reman'd unit is bad/leaking. Improper bench bleeding can damage a MC also. Man up and get a new MC If there is one area of your car that you really dont want to cut corners its the brakes. Your life depends on them working properly.

 

I looked at it closer and I think the fluid is either leaking from where the resivour meets the MC or from that damaged blake line nut but at this point Im still not entirely sure if Im even losing any fluid. Between Ryan and I going back and forth bleeding and checking and tinkering it's possible that we just lost some and forgot to top it off. if the rubber hose lines up front were severely damaged could that cause this kind of problem? I noticed that up front the lines are cracked and dry rotted, I know they can stretch but I didn't think I would lose total brake feel because of it.

Then again it could be a combination of things I suppose, air in lines, busted rubber hoses etc.

 

Make sure there are NO leaks at the MC at all.

Unless your rubber lines are leaking then they're not going to cause this much of a problem. Excessive stretching of the lines will cause a squishy pedal, but not as bad as you're explaining. There'd have to be a hole or tear in the line. But replace them anyways...no sense in having them on the brink of failure.

 

Okay so here's the update, over the weekend I bought two bottles of high quality DOT3 and flushed the entire system starting from the passenger rear, driver rear, passenger front, driver front. During the bleed/flush I saw almost no air in the system, From the get go I had no leaks air or fluid. I still have a very soft pedal that occasionally firms up to almost normal, most of the time my brakes work just barely enough to drive around town, the only thing that saves me is downshifting. I've already put on new rotors, pads up front and the rear is plenty fine, I put on the reman MC and bench bled it until no bubbles whatsoever, I have ordered some new brake hoses for the front. Anyone have ANY ideas?

 

the master could still be letting fluid past the piston. It doesn't necessarily have to be losing fluid to not work. The piston seal may not be sealing properly and so fluid is pushing past the piston which creates extra volume in the brake system. That could be your squishy pedal. Just an idea since all other options seem to be dead ends. Another thing could be fluid leaking at the caliper seals.

Like I said before, improperly bench bleeding (or just improper bleeding in general) can damage a MC. And if your reman'd unit wasn't completely overhauled or maybe shouldn't have been a candidate for an overhaul then its failure could've come easy. Regardless it should have some sort of warranty on it so you should try exchanging it for another. If its under warranty then its at no cost to you (except more brake fluid )

 

Thanks a lot J, I'll end up taking it back or at the most extreme, buy a new one altogether. If I can find my old Z at the junkyard I might try and get that MC if it's still in good condition because that one was new and proven to work properly. How exactly could I have damaged the MC while bench bleeding, to avoid doing that again?

 

not centering in the cylinder bore before pumping it (make sure whatever you're using to bench bleed is centered in the cylinder and that you push it straight in). Pumping it too far in(Don't pump it til it stops. Get a feel for it and stop short). Pumping to rapidly (smooth and steady). All those can cause failure. I guess damage was a harsh word. Failure is a better word.

 

Uhm wow, so you just told me that I did it all wrong HAHAHA. Yeah so Im going to go ahead and return this MC because I definitely pumped it all the way in each and every time and Im sure I went too fast a few times. . ugh seems like some sick reference to sex but, oh well at least we (you) figured out the problem. Only thing is, I have to return this MC but, they have to order another one from the warehouse, so I won't have a car for however long I have to wait, most likely a few days if not just one day.