Brake issues! Help

[vbgambini]

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. 

[Patcon]

If the push rod from the master cylinder through the booster is adjusted too long then the fluid can't push back from the brakes. They getter firmer and firmer and then heat up causing them to lock down. If you crack open a bleed port, fluid will probably spurt out and the car will roll again...It can be trial and error to get the booster rod adjusted right. Don't drop the reaction disc!!!

[madkaw]

Did you replace the rubber lines?
Rebuilt calipers are like 40$ a side, just do it


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[sweatybetty]

15 hours ago, vbgambini said:

.rear driver side has new shoes, passenger side had pretty good meat on it left so I left it.

one other thing. generally, it is standard practice to change all the brake shoes at one time, not just one side. brake shoes, turning the drums and new hardware are fairly cheap.

[KDMatt]

16 hours ago, Patcon said:

If the push rod from the master cylinder through the booster is adjusted too long then the fluid can't push back from the brakes. They getter firmer and firmer and then heat up causing them to lock down. If you crack open a bleed port, fluid will probably spurt out and the car will roll again...It can be trial and error to get the booster rod adjusted right. Don't drop the reaction disc!!!

+1

This is exactly what it sounds like to me. I think he mentioned that he replaced the booster -- I can't remember since it's been a while, but replacement boosters typically include new rods don't they? I think I remember seeing that OP's replacement booster was for a 2+2, which might explain why the rod length changed. 

[vbgambini]

Tried to replace the rubber front lines at least to the stainless ones I ordered but the nut started to strip, even using the flare wrench. So I stopped on that for now. As for calipers, eventually I will replace them as well. Just wanted to make sure I have everything else correct before doing that.

As for the push rod, I messed with it so much before when installing the booster, really thought I had it right. But thats would I will check as son as I can. Can anyone try to explain to the best or their ability on how soft the pedal should feel? When I was installing the booster and MC I felt the pedal still soft. To me at least but I am also comparing to newer cars on how stiff they are. Thats maybe why I have the rod too long. 

MSA also asked to check the check valve too. Could that be the same issue as well? 

Im leaning towards the push rod though, but just seemed like when I had it adjusted before it seemed fine. 

[KDMatt]

20 minutes ago, vbgambini said:

Tried to replace the rubber front lines at least to the stainless ones I ordered but the nut started to strip, even using the flare wrench. So I stopped on that for now. As for calipers, eventually I will replace them as well. Just wanted to make sure I have everything else correct before doing that.

As for the push rod, I messed with it so much before when installing the booster, really thought I had it right. But thats would I will check as son as I can. Can anyone try to explain to the best or their ability on how soft the pedal should feel? When I was installing the booster and MC I felt the pedal still soft. To me at least but I am also comparing to newer cars on how stiff they are. Thats maybe why I have the rod too long. 

MSA also asked to check the check valve too. Could that be the same issue as well? 

Im leaning towards the push rod though, but just seemed like when I had it adjusted before it seemed fine. 

Did you ever check your reaction disc? Be careful you don't lose it in the booster if you mess with the rod!

[vbgambini]

never checked it. Just started to adjust it the way it was. Isnt that disc inside? I just started to adjust as the booster came.

[Patcon]

The pushrod on the master cylinder side of the booster just sits inside the booster. There is a small rubber disc maybe an 1" in diameter and a 1/4" thick that just sits between the pushrod and the main plastic disc inside the booster. If you pull out the pushrod to adjust it, the disc can fall down into the booster. Then you have to remove the booster and shake it to try to get the disc out. No fun! The brakes should get firm. If they don't I would suspect worn rubber brake lines flexing or air in the system somewhere. Make sure the bleed screws on the front calipers are on the top! Sometimes you have to resort to really tight channel locks to get the brake lines loose but many times that requires some new lines