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1983 Spider Veloce
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Discussion Starter · #1 ·
Hi all, I need some help with my brakes.

My '83 Spider Veloce lost it's brakes while driving today. The pressure slowly went down until I couldn't brake at all (over the course of ~5 miles or 10 minutes of backroad driving). I puttered into work using my parking brake.

The brake pedal regained it's stiffness for a short time while sitting in the parking lot. Continuous pumping revealed air bubbles coming up through the rear of the fluid reservoir when letting off of the break. A buddy held the reservoir down tight and I pumped the brakes again with fewer bubbles coming through. Also, there were no leaks until after securing the reservoir down with a pipe clamp, at which point the bubbles nearly stopped, but fluid very slowly dripped down from the middle of the master cylinder where it meets the booster(? idk the big round thing's name) after pumping the pedal hard.

Our hypothesis: the rear O-ring on the fluid reservoir has dry rotted and needs to be replaced. I've heard of replacing these, but I genuinely have no idea how to get the reservoir off of the car without breaking it! Is there a way to remove the brake fluid reservoir without taking off/replacing the whole master brake cylinder? Any other suggestions for where I should check?
 

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They rot in the air and ozone and heat. You pry the reservoir off with a big screwdriver or pry bar. If the seals are perished it should come out readily. You can get new seals by themselves, but if they're that old I'd sure question the state of the brake MC. And you're going to need to bleed, most likely, so replace?
Andrew
 

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1983 Spider Veloce
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Discussion Starter · #3 ·
They rot in the air and ozone and heat. You pry the reservoir off with a big screwdriver or pry bar. If the seals are perished it should come out readily. You can get new seals by themselves, but if they're that old I'd sure question the state of the brake MC. And you're going to need to bleed, most likely, so replace?
Andrew
Thanks Andrew! I've found the grommets on Centerline for $17, so i'll definitely try those first. I have heard of kits to replace the internal o-rings. Do you know where I could find one of those? The kit on centerline only shows boxes, so I'm not sure what I'm getting if I ordered that one.
 

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That's totally different. The rubbers on top are on the gravity side, sealing the reservoir to the master cylinder. The o-rings inside, you're rebuilding the master cylinder. If you haven't done it before I wouldn't start now. I'd buy a new MC, install, bleed. Watch out for the o-ring on the end of the MC that seals the vacuum into the booster. And look in the booster for any fluid, having maybe leaked out of the MC into it.
Bleed afterwards. You know how to do all this?
Andrew
 

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1983 Spider Veloce
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Discussion Starter · #5 ·
Okay. I do know how to do all of it except for looking inside the booster (I assume I look through where the MC is?) Attached are some images (sorry for the blur, but you guys understand). Would finding an o-ring to replace the seal at the booster be an option? I also think the rubbers on top are bad because the brake reservoir wiggles pretty easily compared to the new trans fluid reservoir.
1697359
1697360
 

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1983 Spider Veloce
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Discussion Starter · #6 ·
Note that the zip-tie is not permanent, but it did seal the system by putting pressure on the reservoir, thus it allowed me to drive home
 

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it's almost a alfa romeo spider
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Okay. I do know how to do all of it except for looking inside the booster (I assume I look through where the MC is?) Attached are some images (sorry for the blur, but you guys understand). Would finding an o-ring to replace the seal at the booster be an option? I also think the rubbers on top are bad because the brake reservoir wiggles pretty easily compared to the new trans fluid reservoir.
View attachment 1697359 View attachment 1697360
the photos are why on things that can rust, and are importand.. i give it a 2 quick shots of black spray paint.. keeps the rust off the parts, and keep any rust from migrating into the threads
 
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