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Discussion Starter #1
Hi everyone,

So first post here. Hope you guys can help me with an issue that popped up today. I have a 1977 280z 5spd. I was driving on the highway when the dash Brake light lit up. I noticed the car was having troubles accelerating immediately after. I figured the brakes were sticking so I took the first turn off, pulled over, and turned the car off. I could smell burning which I assume was the brakes cooking. After I got out I could feel a fair bit of heat coming from the rear drivers side tire. No smoke, but It definitely smelled like it was burning. I sat a bit to let it cool and after a short while I fired her back up (Dash brake light still on as before). I pulled the e brake and re applied it a few times cause I thought that could be the culprit. Eventually the light went out after pulling and release the e brake several times. The rest of the drive back no problems. So im confused how this happened. I was fine for most of the drive and all of a sudden the brake becomes stuck?

I'm pretty new to these cars and cars in general. Hoping for some help to determine what went wrong.

I did check the master cylinder and all the fluid levels were normal.

Any help is greatly appreciated.
 

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Something like this has happened to me, although in my case it was a disc brake caliper problem. I would focus on the specific corner that had the problem. I believe you have rear drum brakes, correct?

My bet is that there is corrosion in the hydraulic cylinder piston bore for that brake, and the brake is sticking. From time to time it sticks, and sometimes it lets go. If it sticks, the hotter it gets the more it will push on the brake shoes.

It could also be a defective part in the brake assembly such as the star adjuster that's too extended.

I suggest you pull the drum for that corner - I bet it's hard to get off and you will have to back off the adjuster to get the drum off - and look at that specific wheel cylinder.

if you haven't flushed out the brake fluid on that car recently, I would also suggest a total brake flush. Water accumulation in the brake fluid often causes corrosion problems with the brake pistons in Z-cars of all generations. It's also a significant problem with the clutch slave cylinders in cars which operate in humid areas.
 

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It's interesting that the brake light came on as that only happens when the car is not running or the ebrake is down (the brake handle pushes on a small switch. So is it possible you didn't put the ebrake handle down all the way or maybe it popped up somehow?
 

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Discussion Starter #4
Something like this has happened to me, although in my case it was a disc brake caliper problem. I would focus on the specific corner that had the problem. I believe you have rear drum brakes, correct?

My bet is that there is corrosion in the hydraulic cylinder piston bore for that brake, and the brake is sticking. From time to time it sticks, and sometimes it lets go. If it sticks, the hotter it gets the more it will push on the brake shoes.

It could also be a defective part in the brake assembly such as the star adjuster that's too extended.

I suggest you pull the drum for that corner - I bet it's hard to get off and you will have to back off the adjuster to get the drum off - and look at that specific wheel cylinder.

if you haven't flushed out the brake fluid on that car recently, I would also suggest a total brake flush. Water accumulation in the brake fluid often causes corrosion problems with the brake pistons in Z-cars of all generations. It's also a significant problem with the clutch slave cylinders in cars which operate in humid areas.
Yep the original drums.

It could be corrosion. At this point I am thinking it might be best to buy a conversion kit and just put disc brakes on the back as well.

When I get a chance though I pull the drum off and have a look inside. I changed out the wheel cylinders last year and put new springs in but that was about it. Fluids are fairly new as well.

Thanks for the advice, I have somewhere to start now. Also if you have converter to disc breaks please let me know. I have heard mixed things from people about it no being worth it. Im leaning towards the change though.
 

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Discussion Starter #5
It's interesting that the brake light came on as that only happens when the car is not running or the ebrake is down (the brake handle pushes on a small switch. So is it possible you didn't put the ebrake handle down all the way or maybe it popped up somehow?
Handle was all the way down. First thing I checked. I did have the light come on once because my master cylinder was leaking and I had no pressure. I believe the light can signal three things. 1. No hydraluic break pressure. 2. A imbalance in the brakes. 3. E-brake is on. I could be wrong though.
 

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Handle was all the way down. First thing I checked. I did have the light come on once because my master cylinder was leaking and I had no pressure. I believe the light can signal three things. 1. No hydraluic break pressure. 2. A imbalance in the brakes. 3. E-brake is on. I could be wrong though.
Interesting, good to know.
 
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