I bought my 68 vette a few years back and the brakes needed to be bled but you could get away with running it around town safely. just needed to press on them a little harder. But the other day I went to step on the brakes and nothin happened. SO I went home bled all the the lines. Tried it again and still nothing. The brake would go right to the flood and nothing would happen. Could this be the master cylinder that is bad? I have no clue when it comes to brakes. Any info would be handy. Thanks.

 

when you bled the brakes did you get air or fluid?
did you keep the master cylinder full......if not you got more air.

start over , follow the proper procedure for bleeding brakes...
and DON'T DRIVE CAR UNTIL YOU HAVE GOOD PEDAL PRESSURE!!!!

 

Step 1 should be to bench bleed the master cylinder.

Ensure 100%; that no air is left in the master cylinder and maintain a good level throughout the brake bleed process.






Dan

 

If you had brakes before and now have none, first check for leaks. If there are no leaks, then the master cal is usually bad. The rubber cups leak and the fluid bleeds back over them instead of going out to the brakes. Vette brakes are a pain to bleed unless you have a pressure bleeder like Motive. I love mine and it makes the job so easy. Best of luck

 

Yea I bled them got fluid coming out of all the lines. Not as much as I would have liked to see But enough to think I should have some stopping power... Is there anyway to test the master cylinder to see if it is bad?

 

You just did.

 

I was also told that it could be the other part that the master bolts to?? the pump or something like that? Or should I just get a master and go from there

 

I think your BEST bet would be to find a knowledgeable mechanic
who had experience with a corvette brake system and let him or her (?)
find the problem.....Don't mess around with brakes when you don't know what you are doing.........

 

Have you ever seen kids play "whack-a-mole"?

You are getting 100% perfect advice, however I will bet that whatever you fix first will lead you to another problem.

Having played this game myself, I would agree that the master cylinder is the first place to go. Might as well change the rubber hoses at all 4 corners just to get this out of the way, and its relatively cheap.

Make sure you bleed all 4 bleeders in the rear.

My adventure felt something like the opening sequence to "Land of the Lost", however after doing two masters, proportioning valve [original leaked], and changed rear calipers and corresponding hoses, I finally have a satisfactory brake system.

 

To check master cylinder unhook brake lines from master cylinder and install plugs in the holes. Pedal should be rock solid. If its not bench bleed master cylinder and try this test again.

Roger

 

But I think you'll search 'til doomsday finding a female C3 Vette brake tech.

 

since you left it go this long, I'm going to go out on a limb and suggest you take it to a shop and have them do it right. you;'re probly not mechanically inclined.

 

cheap radio is ok, less than perfect carpet is no problem but....

NEVER cut corners on things having to do with going or stopping

A life is always worth more than a few dollars saved in a repair shop

 

Why has no one asked if this car has power brakes. If the booster is bad it can allow the pedal to keep getting lower and lower the worse the booster is.

Case in point, I was having a problem with my brake pedal going lower and lower until finally I said enough is enough. I tested my master cylinder which was only about 4 years old using the same method that roger3 described. Brakes were rock solid. I hooked up a vacuum pump and gauge to my booster and found that when I pushed the pedal down about two inches I would lose vacuum which meant that I had a hole in the diaphragm in the booster. After removing the booster I found that it was probably the original and had fluid in it from a previous master cylinder. New booster and now have more brake then I ever imagined.

After installing the new booster and a new master cylinder just to be on the safe side I decided to start with fresh fluid in the whole system. I started by just opening up each bleeder one by one, starting with the right rear, left rear, right front and then left front, letting the fluid drain into a container through a piece of clear 3/16 ID tubing stretched over the end of the bleeder. I let the fluid gravity feed until I got clean fluid at each bleeder. After I did that I had solid brakes with no additional bleeding. If you do this, DO NOT LET THE RESERVOIRS GET EMPTY or you have to start all over again.

Look at the other thread I posted which tells what I did to raise my brake pedal from being a max of 4" off the floor to about 5 1/2" height.

http://forums.corvetteforum.com/c3-t...-question.html

 

tmylott55,

That's good advice. Just to put all the steps in order:-

1. Check if the MC is good or bad by above test (roger 3). If you can push the pedal down with the plugs in, then fluid is passing the rubber seals, therefore the MC needs to come out and have a rebuilt kit put through it. Follow Big Block Dave's advice and replace all four rubber hoses.

2. Bench bleed the rebuilt MC in a vice or in the car. You can do this by obtaining two one foot lengths of brake line with appropriate fittings for each outlet. Screw them into the MC outlets and carefully bend them up and back and down so that the ends sit under the fluid level in the MC. Slowly pump the pedal until no more air bubbles come out of the pipes. One at a time, remove these bleeder lines and replace the factory brake lines.

3. Open the bleeder(s) on any cylinder and wait until gravity pushes the fluid and air (bubbles) out, using Red 71's method. Make sure you keep the MC fluid level up. When only fluid comes out, lock the bleeder and go to the next caliper, any order, remembering the rear calipers have TWO bleeders.

You will then have a good brake pedal.

Regards from Down Under.

aussiejohn