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Looks like the problems are growing a little bit . You said you have already removed most of the old fluid in the master cylinder and replaced with fresh . So now you have to try to keep fluid in the master as you undo lines and hoses , Dont let it run dry up there as it will get air in and then you have to bleed the whole system .Maybe if you can get help while you replace each line ,get someone to keep an eye on it and just top up as needed. Or if you work quick enough you can do one line and recheck yourself
If you decide to replace the short steel line ,make sure you brace the brass block as the pressure you put on that line nut to undo it will try to turn the block over with it , I use a big open end spanner on the top edge of the block , its awkward to work down in the area for sure but it is doable.
That small nut on the line looks to me anyway like someone did hammer on a too smaller spanner to get the nut on , Vise-grips make way more of a mess
After all the lines and washers are replaced then its onto the bleeding …….
Looks like the problems are growing a little bit . You said you have already removed most of the old fluid in the master cylinder and replaced with fresh . So now you have to try to keep fluid in the master as you undo lines and hoses , Dont let it run dry up there as it will get air in and then you have to bleed the whole system .Maybe if you can get help while you replace each line ,get someone to keep an eye on it and just top up as needed. Or if you work quick enough you can do one line and recheck yourself
If you decide to replace the short steel line ,make sure you brace the brass block as the pressure you put on that line nut to undo it will try to turn the block over with it , I use a big open end spanner on the top edge of the block , its awkward to work down in the area for sure but it is doable.
That small nut on the line looks to me anyway like someone did hammer on a too smaller spanner to get the nut on , Vise-grips make way more of a mess
After all the lines and washers are replaced then its onto the bleeding …….
Not so much of good down here at the moment ! wet cold and windy this morning / today ! go find some washers and get into it and get that nice car back on the road
I didn't realize there was an issue with the prop valve. Is this one that has the "leak protection" or whatever they called it back then? Those can be a pain to bleed.
If you want to vacuum bleed, I highly recommend the "genuine" mity-vac vacuum pump. https://amzn.com/B00265M9SS is one example.
My brake line arrived today. The car has been sitting for about 3 weeks now without being driven (I only moved it into the middle of the garage during that time). And before that, I've driven it probably an hour total since I bought it in February, because it was apart for a good amount of that time as I was trying to remove the gas tank and get to the build sheet.
Yesterday, I noticed a drop of brake fluid on the cardboard under the DS brake caliper, in what appears to be a very slow leak. My question: is it possible that it is leaking due to lack of use, in which case it might go away once I start driving it more? While I am certainly willing to do it if I have to, the last thing I want to do right now is down the car for even more time while I figure out how to rebuild a caliper.
The brake hose is dry and the drip appears to originate from the outboard half of the caliper. Interested in your thoughts--
If you witness "One" drop now, you will see ten drops when pressure is applied. You know what you have to do! Grab that For Sale sign and . . . .
Just kidding.
Must be the "O" Ring between the halves. Off comes the caliper . . . . . again.
No other part of the C3 gets cussed at more than the brake system. Frustrating.
Last edited by HeadsU.P.; Jul 25, 2018 at 06:49 PM.
I going out on a limb here and assuming that you definitely knew that none of the calipers had any leaks before this whole project started. If they did have even a slight leak, then you found the answer to the pulling. I am also assuming that the collapsed brake hose theory is dead?
BTW-I have been gravity brake bleeding my system for 30+ years with success. If the system in totality is operating correctly, you should not have to do anything special to bleed the brakes.
I going out on a limb here and assuming that you definitely knew that none of the calipers had any leaks before this whole project started. If they did have even a slight leak, then you found the answer to the pulling. I am also assuming that the collapsed brake hose theory is dead?
BTW-I have been gravity brake bleeding my system for 30+ years with success. If the system in totality is operating correctly, you should not have to do anything special to bleed the brakes.
Thanks for your input. I can't say for sure that there were no leaks before, but now that I'm seeing the drips, I wouldn't be surprised. As far as the hose theory, I suppose it doesn't matter much as I'll replace them either way.
Do I need to do a full rebuild of the caliper? Or as HeadsU.P. said, can I just replace the o-rings? And BTW, my plan is to try gravity bleeding. Been checking it out online. This video really helped me with the concept:
If you are going to pull the caliper apart anyway, then just replace the piston seals as well. It is easy to do. I had a SS caliper that developed a leak in the early 90's and I pulled it apart, replaced the o rings and lip seals, slapped it back together and all has been perfect since that time.....fairly easy and straight forward
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
A vette brake rebuild is easy so don't sweat it. Just listen to what the guys here are saying on how to do it. I bleed my brakes by gravity and followed by the tried and true method of pumping the brake and cracking the bleeder to remove any trapped air.
See one drop of fluid and change your repair strategy? I think not. You need to replace the brake line and change all four of those old, rotten-inside hoses, to be sure.
Can a caliper brake lose any fluid just sitting there for a long period of time? Don't know...maybe. But, when working around that caliper, you should check out the caliper and piston seals.
To those who have not had a rotten hose cause a partial apply in one wheel: You haven't had this happen to you, so you don't believe it. That doesn't mean that it is bogus and can't happen. Those of us who have had this occur can attest to that.
Last edited by 7T1vette; Jul 26, 2018 at 10:02 AM.
See one drop of fluid and change your repair strategy? I think not. You need to replace the brake line and change all four of those old, rotten-inside hoses, to be sure.
Can a caliper brake lose any fluid just sitting there for a long period of time? Don't know...maybe. But, when working around that caliper, you should check out the caliper and piston seals.
To those who have not had a rotten hose cause a partial apply in one wheel: You haven't had this happen to you, so you don't believe it. That doesn't mean that it is bogus and can't happen. Those of us who have had this occur can attest to that.
I've already decided that I'll be changing the hoses. But when seperating the caliper halves, what would I see that would make me know I need to change out the piston seals? Along those lines, would there be any reason I would need to change out the pistons themselves? I'm just not sure what I'm looking for.
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Those parts are relatively cheap to buy so while your in there......... If the pistons are pitted you can replace them but if not just buy the seals and 'O' rings for the caliper halves. Probably all you need comes in a rebuild kit sans pistons.
Last edited by resdoggie; Jul 26, 2018 at 02:16 PM.
based on your description of brake fluid flow when you have partially opened the system, I am assuming the brake hose collapse possibility may not be the cause. Of course, a collapsed brake hose could always be a possibility, but I think in your case, that may not be the cause of the pulling...just to be clear for some that are making broad assumptions about what I proposed for THIS case.
based on your description of brake fluid flow when you have partially opened the system, I am assuming the brake hose collapse possibility may not be the cause. Of course, a collapsed brake hose could always be a possibility, but I think in your case, that may not be the cause of the pulling...just to be clear for some that are making broad assumptions about what I proposed for THIS case.
Thanks. I actually haven't opened any part of the system up yet. I've only removed the wheels. The plan was to replace the DS brake hose, but as you know the brake line fitting was rounded. Just gathering all the facts and learning as much as I can before I do anything. Normally, I don't like to just throw "parts" at the problem.
go find some washers and get into it and get that nice car back on the road 
You definitely get my vote for the funniest forum member!
