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Discussion Starter #1
Hello, my name is Joey, and i am new to the forum. I have done some research on this subject, and i cant seem to find people that have had the same exact issue. Basically, to make a lot story short I i recently purchased my first alfa spider:001_tongue: . When i got it home i realized the brakes were TERRIBLE! They were like glue every time i depressed the brake! So, needles to say i bought master cylinder, lines, brakes, rotors, and rebuilt the calipers. Due to the overwhelmingly low price i bought the car at i was prepared to put in the cash and labor. After that fact they worked perfectly. Until after a few miles or so they lightly stick for a brief moment and come back to normal (almost every time i depress the brake). Could it be that the pistons in the calipers are expanding a bit and cause some stick? Could it be something as simple as a weak return spring on the brake pedal? Or maybe my expectations are to high? Or maybe all lol? Any thoughts? Here are some pics of the parts i rebuilt/installed.





 

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The rotors pictured... All the front rotors I have ever seen, and installed had lug studs already in them. Why do the ones you have pictured (only the fronts) not have that?
 

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Does your Spider have suspended pedals or ones that are pivoted at the floor?

On the older 105 series cars with floor pivoting pedals, and Bonaldi master cylinders beneath the driver's floor, the Master Cylinder push rod length is critical.

If it is a mite too long, it will lead to your type of problem.

Fortunately this rod is adjustable. Check the manual for length and adjust this rod.

Unfortunately we never saw Spiders with hanging pedals in my neck of the woods so I'll let someone else chime in here with a fix for those.

Enjoy your Spider.
 

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Joey,

As asked in another post, does your car have floor mounted or hanging pedals?. I have a '76 Spider that had a similar sort of problem you mention after I installed a new brake booster. In my case, the brakes were dragging slightly after driving a few miles and warming up. My car has hanging pedals, and the master cylinder rod isn't adjustable. My temporary fix was to place .020 in. shims between the master cylinder and brake booster; creating the equivalent of a shorter rod. This was intended to be temporary until I could find a proper solution, but has lasted until the end of the autocross season, and I need to solve the problem before my fellow BB'ers attack me for a kludge type work around.

Hello, my name is Joey, and i am new to the forum. I have done some research on this subject, and i cant seem to find people that have had the same exact issue. Basically, to make a lot story short I i recently purchased my first alfa spider:001_tongue: . When i got it home i realized the brakes were TERRIBLE! They were like glue every time i depressed the brake! So, needles to say i bought master cylinder, lines, brakes, rotors, and rebuilt the calipers. Due to the overwhelmingly low price i bought the car at i was prepared to put in the cash and labor. After that fact they worked perfectly. Until after a few miles or so they lightly stick for a brief moment and come back to normal (almost every time i depress the brake). Could it be that the pistons in the calipers are expanding a bit and cause some stick? Could it be something as simple as a weak return spring on the brake pedal? Or maybe my expectations are to high? Or maybe all lol? Any thoughts? Here are some pics of the parts i rebuilt/installed.
 

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Discussion Starter #6
Joey,

As asked in another post, does your car have floor mounted or hanging pedals?. I have a '76 Spider that had a similar sort of problem you mention after I installed a new brake booster. In my case, the brakes were dragging slightly after driving a few miles and warming up. My car has hanging pedals, and the master cylinder rod isn't adjustable. My temporary fix was to place .020 in. shims between the master cylinder and brake booster; creating the equivalent of a shorter rod. This was intended to be temporary until I could find a proper solution, but has lasted until the end of the autocross season, and I need to solve the problem before my fellow BB'ers attack me for a kludge type work around.
Hello conedriver,

This was my first post on the forum i think you may be thinking of someone else. Were definitely having the same problem though. Maybe we can try to readjust the pistons in the calipers, maybe they are not positioned right like that post below is suggesting. I would say if that doesn't work i will end up making an adjustable rod on the lathe maybe that would work? So, the shims work well, because my pedals are hanging too with no adjustment? Its an 86' spider btw.
 

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Discussion Starter #8
Does your Spider have suspended pedals or ones that are pivoted at the floor?

On the older 105 series cars with floor pivoting pedals, and Bonaldi master cylinders beneath the driver's floor, the Master Cylinder push rod length is critical.

If it is a mite too long, it will lead to your type of problem.

Fortunately this rod is adjustable. Check the manual for length and adjust this rod.

Unfortunately we never saw Spiders with hanging pedals in my neck of the woods so I'll let someone else chime in here with a fix for those.

Enjoy your Spider.
Thank you for your time! I will keep this in mind!
 

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Discussion Starter #9
For anyone else viewing this post... I would just like to say that i fixed it, but now i have to figure out why... I unplugged the master cylinder brake booster, and it works great. The brakes are amazing. So now, for the big question. Why does the brake booster make the brakes so sticky? The brakes now feel like race brakes because they are a little more difficult to depress, but im okay with that.

Has anyone had similar issues? Does anyone know how a brake booster works exactly? I used to think i knew, but now, i think its time to learn some more.
 

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It sounds like a defective vacuum control in the booster self applying the master.
 

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It would be a component of the diaphragm/valve assembly. As to whether replacements are available some one else will have to step in. Sorry I can't be more help.
 
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