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HybridZ

Brake issues 1978 280z


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Yeah, when I swapped out my booster, I put the boot into the firewall first, and then installed the booster with a light amount of grease. Works much better that way usually because the boot won't bunch up on the booster.

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Update of what I went through:

 

Installed everything pretty much today. But still have to install my SS lines. I know the rear brake hoses are pretty new, fronts do look like they need changing. So far no leaks seen anywhere.

 

- I had to pull out the booster so many of times to line up the brake pedal inside the car to fit the pin that holds onto the brake pedal and adjust and adjust and adjust. 

 

- Bench bled the MC as much as I can. 

 

- Bled all 4 corners.

 

- Had to adjust the push rod longer a few times because brake pedal felt so spongy. Seems like it is more than 10mm like FSM says. Pumped the brakes with the car off and felt stiff, then when I started the car with my foot on the brake it fell just a little like it should.

 

-Finally got it a little better but for some reason I feel it is still not firm enough. I also feel after I let off the pedal it comes up slowly with a little hesitation at the top top.

 

But I still feel it is pretty spongy. How firm is the pedal to feel when the car is started? Should I bleed the MC again in the car? Is there a way to adjust the pedal inside the car without having to remove everything all over again (Cant spin the adjustment fork without the pedal in the way)?  Too much free play? I would like these brakes to feel as stiff as my newer car and jeep (02 and an 05) Or is it not going to feel that stiff in these older cars with drum brakes?

 

BTW My ebrake goes up 6 clicks like it should so I didn't mess with adjusting the rear drums again. 

 

Im lost right now. What should I do?

Edited by vbgambini
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Update! 

 

Tried to put on my SS brake lines in for the front, but when getting the old metal hard brake lines with a flare wrench, they rounded off. So now the flare wrench cant hold on. My question is how long of a brake line will I need from the brake hose to the master cylinder? Is that hard line even going to the MC? 

 

I want to change the hard line that goes from the hose to the caliper as well, and it seems Z Car Depot has an 8'' one I need. But Z Car Depot has 20-40'' of hard brake line that im figuring for the other line that goes into the engine bay. Which do I order? Never done hard brake lines before and how to bend them. They say you can just use your hands and will not kink. Is that true?

 

Or should I get it done at a shop? But I am worried they wont have the fittings like stock to fit my SS lines. Thanks guys.

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I can't tell you what specific lengths you might need for doing your own brake lines, but i did do a custome brake line setup on a guys old truck from pretty much the master all the way to the calipers. if you're patient its Easy to bend the lines by hand. just make sure you have the right size fittings and tube diameter. idk how confident/experienced you are but if you are any kind of mechanically inclined brake lines are pretty damn easy.

Edited by Equizyme
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Cool. Thanks. I mean im no mechanic but gone through some stuff with all my cars lol. Just want to make sure since this is my brake system. Need it to be safe. Just trying to see if anyone has any first hand experience with certain lengths on how to tackle this right the first time thats all. Thanks for the info. Like the sound of pretty easy lol.

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Suggestions

 

- brake booster: leave the firewall nuts loose (few turns of nuts) until you have the pedal connected.

 

- I use a soft alloy brake line because it is easier to bend and flares well.

 

- The Z uses an inverted flare. Buy the best flaring tool you can afford.

 

- You can bend the lines by hand, but small radius bends are better done with a proper bending tool. I use use two bending tools: one for large bends and one that looks like pliers for very small bends.

 

- I bought the bending tools at Harbor Freight and the brake line stock at Summit Racing.

 

- I suggest that you search the Brake forum for brake line flaring and proper tools. I use use a bench mounted flaring tool that makes perfect flares.

 

- As far as measuring brake lines you can remove the line and use a tape measure or use rope to follow the bends and then measure the rope or you could measure using a coat hanger.

 

- Most autoparts stores sell Japanese style brake lines with the correct fittings and flare. Lengths are typically 12in to 36in.

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For the flex lines you can use a coat hanger to estimate the length. Always move the suspension and steering through full motion to verify the flex lines are not being stretched or rubbing or kinking etc. Someone here recently forgot to do that and his SS flex line abbrated a brake hard line until it cut through the line - no brakes.

Edited by Miles
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Cool. Thanks for that info. Never tackled hard brake lines before so I really want to get this right. I did order my SS lines from MSA so Im hoping they are the right length. Anyone try a good vise on the rounded nuts? If anything a shop can do this right? With the right fittings just in case I mess up? Or does it have to be a specific kind of shop?

Edited by vbgambini
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  • 3 months later...

Update

 

Took the Z out today for a little drive after a few weeks of it parked in the driveway. Last time I drove it is when I installed a new brake master cylinder and booster. Drove fine for about 10 minutes, then I started to smell a burning scent. Thought it was just because I havent driven it in a while but then it continued. As I drove a little more the pedal became stiffer and stiffer. So luckily I was close to home and as soon as I pulled into the driveway, the pedal got very stiff. Same feeling I got before the master and booster were changed.

 

Checked the handbrake, it was fully down, and now it barely can move like as if the handbrake was up. Felt like the brakes were binding or seizing up. History of the brakes are, front pads replaced, rear driver side has new shoes, passenger side had pretty good meat on it left so I left it. New master cylinder bench bled to the best I can, and new booster. Bled the system many times as well. Front calipers are still original I believe.

 

Now it just seems like the brakes are stuck not letting me move as if the handbrake was engaged. Any ideas what to check? I remember when changing the front pads, one of the caliper piston rubber seal did not look too good. Could it be that? Smell seemed like it was coming from the front, but not fully sure. Did not seem to lose any fluids, did not see any leaks on the driveway. Help would be appreciated. 

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Seems like we all went over this with you a while back.

 

You have the push rod adjusted too long such that fluid pressure is building up each time you push the brake pedal causing the brakes to lock.

 

Open the bleeders on the MC to relieve the pressure and readjust the push rod as outlined in the FSM or search in the brake forum.

 

Search the brake forum for "push rod adjustment".

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Sorry about this. I really thought I adjusted it to the right length because when I drove it then it was fine. Actually thought it was too short because I felt the pedal was still too soft.

 

So do I bleed the MC again after adjusting it? Then drive it to see or can I just do this while parked?

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Sorry about this. I really thought I adjusted it to the right length because when I drove it then it was fine. Actually thought it was too short because I felt the pedal was still too soft.

 

So do I bleed the MC again after adjusting it? Then drive it to see or can I just do this while parked?  As stated above, leave the lines attached and push the MC to the side to access the push rod. Adjust the push rod in small increments and test drive after each adjustment. Soft brakes can be another issue.  Solve one problem at a time. If you haven't done so, search and read all of the posts on "push rod adjustment". 

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