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Afternoon Gentlemen and devious delinquents,

Wanted to thank everyone for the help with the clutch install, twas greatly appreciated and lots of help! Now that I have finally had a chance to romp on it a bit I've found I need to go over the carb, as I get a nice big bog when I hit the floor with the pedal, but nice pull when I gently increase throttle. (Thinking accelerator pump but I'm going to rebuild the entire carb completely this winter anyways so most likely this is a project and writeup for the fall/winter)

***These brakes are still new to me, so if I have described something in error please let me know and I will do my best to correct the OP etc with comments. Ive done some research to try to understand but I do have limited personal experience with lip seal type calipers***

The next upcoming project and reference post is to get some of the brake work done over the next few weekends. Ive done a lot of research on different brake lines, piston seals etc. I deffinetly suggest people considering serious brake work to review some of the other posts and learn about flare types, material choices, typical failure points.

Now that I've been underneath my '76 for some decent time (Thanks 16 hr clutch fix...) I've noticed I have a lot of my steel lines corroding to the point of me leaving extra room between cars for fear of failure. I decided on SS brake lines from zip that are pre-bent with all the corresponding fixtures. Don't forget the screws and clips as well cause fighting rusty bolts is annoying when ~10 bucks buys an entire set. I also purchased a new SS parking brake kit, with new shoes, star wheel, lines, pulley, spring etc etc. Nice kit all in all. Also bought new rotors as I still have my original rivets....

Here is where some of the more interesting topics start to manifest. GM used seals on the pistons of their brakes. This is a bit different then other designs I have worked on for jap bikes and *gasp* mopar where the seal is inside the casting. They also used a lip seal design instead of a square oring type seen on other designs. There are tons of designs with pros and cons, however these lip seals give our C3 corvettes some trouble. Ill list a few of the issues that I have read about and let some others chime in with more experience.

Issue 1) I believe there is a sticky by gtr1999 (http://www.digitalcorvettes.com/forums/showthread.php?t=77063) that details going over and installing new rotors. Some of the reasons he does such a thorough job is because our calipers are fixed. This means that the calipers do not float nor track with the rotor as it rotates. This means all run out of the rotor pushes against the pads, which then pushes against the pistons of the brake caliper. I have not had this happen to me yet *and pray it never does* but this action supposedly causes a pumping action that can fill your system with air as the lip seal is not designed for this type of oscillatory motion. Our brakes are well designed if kept within factory tolerances (e.g. a runout of 2 mils like gtr shoots for). gtr uses shims to reduce this runout, which I think is a great practice. I am actually looking into these Brake Rotor Shims (http://www.rockauto.com/catalog/raframecatalog.php) instead of making my own to make sure that my runout is small. This helps to eliminate the oscillatory motion described above.

(Gotta run to harbor freight for a bit, Ill keep updating later today on this post)

Aight sorry that took awhile, got rather busy at work.

So onto Issue 2)
Metal hit on this some, Stainless sleeves on the calipers. So original castings are iron, and like all cast iron it tends to rust with 30 yrs of use. People started boring the calipers, inserting stainless sleeves to "freshen" the surface. This also provides a nice surface for the piston to seal against. Along with these new calipers was a new piston design, which I believe has a slightly different cut into the piston for an O-ring seal. (means u shouldnt/cant but need to verify use an oring on a lip seal piston). Metal was right that you can get these for 85$ or so for a single caliper, which is pretty cheap for a bolt on. (Im going to buy 2 for the rear as thats where my current leak is) These are touted here and on other forums to fix "leaky" calipers due to non-use.

Now a curious question that I pose is how this will affect the sensitivity to runout of the rotor. If the rotor has significant runout, say 6 tho or so, but one has o-ring style calipers, the oring itself seals in both directions unlike the lip seal. So there is not quite the same pumping action I would think. Also with a nice new stainless surface for the Oring to seal against I would hope that it helps the problem even more. Anyone with specific experience? I am assuming that if one took the time to measure their runout they would most likely not leave it to test the calipers and they would shim as required. I am thinking that they might give us some more leeway in the runout area potentially by utilizing this "updated" design?

Bike calipers that I have torn apart actually use a stainless/brass piston and put the square seal in the caliper (think i mentioned this earlier) and I was curious if newer C4-C7 brakes or even brembos/wilwoods utilize similar methods?

Issue 3)

before I get started working soon, Jet brought to light something that I was curious about. (This is why I love this forum, people are helpful and willing to lend a hand or 0.02$) and that is with these "pre bent stainless lines" how good is the fit? It sounds like Jet had some issues and thats starting to worry me. (Especially when I wanted to replace all my lines in a day, plus calipers and Ebrake lol, I know im nuts and thats most likely a 2 weekend job) I wouldnt think Zip would give out this type of product if it wasnt at least checked for fit, but then again they may purchase from someone else?

Issue 4)

Also brought to light by Jet was the fact of the front to rear solid line that goes along the frame of the body connecting the rear brakes to the front switch. I have "heard rumor" that one must lift the body off to replace this line. Can I lift just the one side or do I need to lift both to get enough clearance? And I am pretty afraid to even look at the mounts atm as I was going to try to replace those this winter and fear what I will find. I have also heard of the "bubba" method, and while I am typically a fan of fixing things right, I do need brakes badly lol. What is the bubba method?

Think I've posted a few good questions to get some dialogged going with some of the experienced members. I will post a semi detailed chronical of my endeavors (similar to my clutch post) so that not only I but others can use as a reference. Out for now......
 

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The next upcoming project and reference post is to get some of the brake work done over the next few weekends. Ive done a lot of research on different brake lines, piston seals etc. I deffinetly suggest people considering serious brake work to review some of the other posts and learn about flare types, material choices, typical failure points.
The brake lines I bought from zip was supposed to be bolt-in, but they didn`t really fit at all:rolleyes:. The lenght was okay, so we bent them to fit the car and installed them. The lines I bought were stainless. You have to remove the body to replace the front to rear brake line. It`s possible to bubba your way around this, but I`d recommend you to install the lines where they are supposed to be installed and without cutting them. Can`t help you with the calipers, I`ve never had to do anything to them. yet...
 

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One recommendation I always make when I hear about someone contemplating an original OEM caliper rebuild is, to save yourself the hassle and buy a set of stainless steel sleeved remanufactured calipers. They're readily available and under $100 each. Bolt in :thumbsup: and you won't have to worry about moisture getting past the seals and corroding the cast iron cylinders, (causing leakage) which is a common problem with the OEMs.
 
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