Brake issues! Help

[vbgambini]

hmmm I might have to try vice grips again. I did try once and it didnt seem to work. They were small needle like grips. Should I try bigger ones? Any trick to it or just stick on there and turn?

Edited April 30, 2016 by vbgambini

[Zed Head]

File the flats smooth and parallel, really clamp the vise-grips on tight (I use full-size, for leverage and more grip area), get a good view of the nut using bright light, then put some force on it while watching for any slippage.  If it slips at all, stop and reset.  Clean the flats of the nut with crab or brake cleaner and dry them off.  Any oil film will allow slippage.  Use a torch or heat gun to heat up the female side.  Leave room for your knuckles, when it goes it will feel like it broke.

If you're doing the junction, put vise-grips on the other side also.  Don't depend on the fitting on the strut, it will round out too.  If you use two vise-grips, set them up so that you can squeeze them like a motorcycle brake lever.  Or press them together with two hands.

[Mark Maras]

 I've had better success using slip-joint (Channel Lock) pliers on rounded, stuck hydraulic line fittings and bleeders than Vice Grips. I resorted to pliers when the Vice Grips just chewed up a bleeder more than it was before. I've found the pliers and a good grip actually do less damage than Vice Grips.

[Zed Head]

Never mind.

Edited May 1, 2016 by Zed Head

[siteunseen]

I'm talking about the small ones that work for me.

Pull the legs of a roach with these.

[Patcon]

A little PB blaster and bigger vise grips. the needle nose vise grips flex too much to really grip tightly

[KDMatt]

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.

[vbgambini]

2 hours ago, KDMatt said:

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.

Thanks for the response!

Yea my brakes felt very spongy and eventually had no brakes. Since the front 2 flex brake hoses had cracks in them, I might as well change them to SS lines. So I ordered 4 SS lines. 

So I figured it was the booster so I decided to change it and while I was there to do the MC as well. They were both in bad shape, seem to be original parts. Have any picture of what the reaction disc looks like? From what I read it is in the booster itself and not an external piece. Would it be stuck in the old MC? I mean the car stops pretty good now but would want it to be tighter and more firm. Do you feel pressure as soon as you press the brake pedal or does it have to be pressed im guessing an inch or two till you feel it? I had to adjust the rod in he booster plenty of times (such a pain) to get where I am at now. But it is definitely more than 10mm like the FSM says it should be. But the brakes feel pretty good. Just want it better.

As for the adjustment on my rear drums, they seem pretty good. Hand brake goes up 5-6 clicks. I adjusted them a while ago.

Yea I plan on painting it soon. Will high heat spray paint do the trick?

Now I have these rounded brake nuts when trying to put in the SS lines and stuck for now. Had to duct tape the crack in the rubber hoses lol. 

[Zed Head]

1 hour ago, vbgambini said:

Had to duct tape the crack in the rubber hoses lol. 

I've done similar things in the past.  One of the great things about these old cars is that they are primitive enough that you can understand things at a fundamental level, to fix problems.  Ponder how duct tape on the outside is going to withstand the pressure from the inside.  It's not really doing anything.  The "SS" brake lines are really just brake hoses with a braided metal protective sheath in place of rubber (which is probably fiber reinforced).  More durable, but most likely have little effect on performance.  I have a set up front myself, but don't know if I'd buy another.

When your brakes were slowly dying, the first thing you should have done, probably, is to bleed them.  And, as I understand things, when the reaction disc is missing the symptom is an on-off brake action.  Probably why they call it a reaction disc.  It moderates the reaction.  The disc in in the booster, not the MC.

[KDMatt]

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!

 

[vbgambini]

KDMatt no man the more info the better! Keep it coming lol. Thanks for helping me out. I might have to throw the vise grips on there and see. And see I am still confused with that picture because that looks like the inside of the booster right? In order to get those parts in the picture. Sorry for being stupid on this but what I am picturing in my head is a disk that goes on top of the adjustment rod that goes into the master? Am I wrong lol. Should I check my old MC and booster? From what I remember nothing slipped out when replacing it.

As for pedal feel I feel like I have to push down maybe like an inch or more till car starts to slow down. But when I am going like 30-40 mph and not a full slam on the brakes but a good heavy foot it stops pretty good. Jerks to the front of the car pretty solid.

Or in that picture that black piece al the way to the left goes into the master? Im so confused lol.

[KDMatt]

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.