someone is always saying that they have terrible brakes ,and they want something better.when new what was the stopping distance from sixty mph.and how does that compare with todays cars ?me i have great brakes ,thats why i wondered why so much trouble.

 

Well, the thing about the C3 brakes is not that they don't stop the car well, 'cuz they do. When they are working properly. And there lies the rub. They are troublesome and finicky. I'm having trouble with my brakes right now, and I replaced the rotors, calipers and lines in 2008.


Scott

 

Agree with the OP. I had the light come on in our '81 and found a weaping RR caliper and a quick search had me thinking the worst about replacing all four. I went ahead and ordered all VBP calipers and lines and just replaced them like on any other car I've done, except for the 2 each rear bleeders, and have not had one problem with them since. The car has never stopped as well as it does now and we couldn't be happier. Was it just dumb luck to do the brakes with no problems?

 

I just started having issues with my 75's brakes. Everything was great, a mechanic bled the brakes before I got the car a few weeks ago. Yesterday morning I was pulling it into the garage before it rained (the top and seals badly need to be replaced), and the car wouldn't stop. Luckily I wasn't going very fast, but I wasn't able to respond with the e-brake before the car crashed into my cabinets. The brake was basically on the floor and I was still going forward slowly. Going in reverse it seemed like the brakes were alright again, but it was not a good start to my day.

Anyway, I know the car has standard rubber brake hoses, so I'm going to be upgrading to stainless steel hoses (and replacing any lines that may have leaks which I haven't found any evidence of).

From reading it sounds like most of the issues with the breaks come from poorly designed calipers? Something about leaking seals... I'm not sure.

I was wondering if anyone had some suggestions about what I should upgrade my brakes to without breaking the bank (calipers, rotors, etc). I've been searching the net for different options. I've seen things from bolt on replacement kits that are equivalent to C6 brakes (very spendy) to some kits that cost as little as $500. I'm not looking for track performance, but something more reliable. I know this model is equipped with power breaks. I'm doubting that I need to replace the master cylinder or the power break system.

I've come across this kit on ebay, but I have no idea if it's any good. http://cgi.ebay.com/ebaymotors/Wilwo...Q5fAccessories

Thanks in advance for any tips!

Tim


Update:
I noticed VBP had been mentioned in a previous post. Their kits seem like pretty good deals! It looks like they come with new hoses, but it doesn't say if they're stainless or not.
http://www.vbandp.com/C2-C3-Corvette...-5-Brakes.html
Any reason to change out the rotors if nothing is wrong with them? Are these higher performance rotors or something? (trying to determine if I could just get the caliper upgrade kit)

 

The C3 brakes were the best out there in their day...and they are still pretty good by today's standards. Obviously, they don't have computers and pulsed-braking, but on a 3000 pound car, they will do the job. As built for production, they will begin to fade when worked hard; but different pads and some air to cool them will help a lot.

The biggest problem for today's drivers is that the components in the C3's braking systems are 40 years old!!! There are things to make them better:

1) change out ALL of the brake fluid. DOT 3 absorbs moisture and most C3s' fluid haven't been changed out for many years (just added to as needed or when bled).
2) replace or rebuild the master cylinder. A simple device that has seals and valves which wear over time.
3) the rubber lines at each wheel are only good for about 10 years (max) without expecting problems [some potentially dangerous].
4) P-valve (or distribution block) can wear or get sticky. Easy rebuild or replacement.
5) owner's have little knowledge or experience at properly bleeding brake systems.

Air gets trapped in the calipers during bleeding and the calipers need to be rapped with a rubber mallet as they are bled to get rid of it. Also, the 'outlet' line from the calipers needs to be charged with fluid at the start so it will help suction the air out of the system. Lots of little 'tricks' to help get that trapped air moving and out of there. The Chevrolet Chassis Service Manual has a pretty good procedure to follow...if it's used.

Many owners, when confronted with brakiing problems, don't read up on how to make their existing system better; they just go spend a bunch of money on "bigger, better" parts...which when installed haven't done anything to fix the existing cause of their problems. It is really better to get the C3 system up and running as it should first. THEN if the brakes aren't adequate (can't imagine that for a street vehicle), bigger and better might actually improve what's there.

As little maintenance as most folks do on these old braking systems, I'm amazed they still work at all. Keep them in good shape and they work great, IMO.

 

I tinkered with mine and until I went thru the entire system from M/C rebuild to right rear with O ring seals has it performed exceptionally well. I now run silicone fluid and after 8 years, pedal is still nice and tight.

 

I'm extremely new at working on cars, so this may be a dumb question... I'd never heard of silicone fluid (DOT 5) so I went and read up on it. It seems like a less hassle fluid than the DOT 3. What did it take to change to that type?

 

 

Your C3 can still out-stop the majority of modern cars on the street using stock components. In 60-0 distances the C5 Z-06 stops less than 10 feet faster.

As others have said, it's lack of even basic maintenance at the root of brake problems on these cars, not design faults.

 

OK, here's the thing, if you ask someone who has never experienced problems with their brakes, they will say "I don't know what you're talking about, they work great and I've never had any problems, these people who have problems must be idiots."
If you ask someone who has replaced every part of their braking system with brand new parts, and is having problems, they will say something like " This is crazy. It should just work. What a crappy design."
I think the real answer may be a little from column A, a little from column B.


Scott

 

I have changed everything but the hard lines an still dont like the pedal after bleeding it a gazillion times.The pedal is getting harder just not wild about the pedal travel.As far as dot 5 gose I would change all the seals and flush all the lines out if dot 3 is what you have in it now before converting over.MOst people dont have any problems till something starts leaking and then after replacing componets have trouble with air in the sysytem.

 

As one who has owned my '69 convertible for 41 years this coming August, I think I can speak with some authority on this subject. Yes, these brakes can be very hard to bleed completely. That being said, if all the components are in top notch condition, then the only thing left is the system isn't completely bled. Reread 7T1's post above, he has it nailed! Bang the snot out of each caliper, not to the point of harming the calipers, but hard enough to knock the trapped air bubbles loose so they come out.

Personally, I have found that Speed Bleeders, a small container that holds the tube below the level of brake fluid as the receptacle for the old fluid, and the two person method is best. My receptacle is smaller than the master cylinder reservoir, so I don't ever run the reservoir dry. But others swear by other methods, so pick your poison, but get the air out!


Pete

 

http://www.roadandtrack.com/tests/ca...orvette_page_2i found what i wanted .go to to the bottom of the page .compare the other cars stopping to the vette .both of them are lighter .the vette braked good then and it can be made to brake good now.

 

Well, a couple weeks ago, when that dumba$$ young girl made a daredevil left turn...at speed & right in front of my oncoming C3...I had no problem putting it in an immediate 4-wheel drift to miss her (and get out of harm's way from the guy behind me). Yep, they still work OK.

 

Understand that people have different likes/dislikes for DOT 3 vs DOT 5 and my explanation may not be technically precise but you'll get the idea. But in general it requires less maintenance once you change over. DOT 3 has an affinity for moisture so when there are breaches in the system, it attracts the moisture. Thus parts rust.

With DOT 5, it does not have the affinity toward moisture but does have an affinity for air or oxygen. If there is a breach, than it attracts air and you get a spongy pedal. My experience was that this gets worse at higher altitudes...like mountains. I live at sea level, so once my brake system was rehauled, it has remained solid.

7T1 hit on it that the entire system must be flushed and than cleaned with denatured alcohol. You are working to minimize DOT 3 contaminants when you add the DOT 5 fluid. That's why its easiest to make this change when you are changing out calipers and master cylinders which have been rebuilt and have been cleaned of DOT 3.

 

If your brakes are in good condition then there's no need for anything else. If working right, they brake well even by today's standards considering there's no ABS.

 

I agree they are very good, but seriously how could they possibly perform as well as ABS brakes???

 

Well, it took me over three weeks to get it done, but I finally did it...

I examined the brakes and determined that one of the calipers and the master cylinder had bad seals. I also figured out that the portioning valve had gone bad and the brake fluid had broken down because it hadn't been flushed in probably 15 years (just bled every time they pulled it out to drive it for the year). Reading your posts and doing some online research, I decided that DOT 5 brake fluid is the way to go for old cars. I wasn't confident that I would be able to adequately flush the system of DOT 3, so I ended up buying a complete set of stainless steel brake lines.

Here's what I'm now running...
Stainless steel lines
Braided stainless steel hoses
VB&P O-ring style stainless steel calipers (powder coated)
New master cylinder
New proportioning valve
VB&P supplied performance brake pads
DOT 5 brake fluid


The rotors appeared to have hardly any wear (couldn't even feel a lip on them). These aren't super high performance rotors or calipers, but braking performance is now awesome! HUGE difference over the old ones. Had the previous owner try it and she couldn't believe the difference.


Thanks for your advice guys!


By the way...
Anyone thinking about doing brake lines, some of the bolts going to the rear brakes are terrible to get out. Pre-bent lines are pretty much impossible to get to the front-right wheel without removing the radiator shroud (which is a much bigger pain that I imagined).